2014-2015 Report to President
The Department of Earth, Atmospheric and Planetary Sciences (EAPS) studies Earth, Planets, Climate, and life and has broad intellectual horizons encompassing the solid Earth, its fluid envelopes, and its diverse neighbors throughout the solar system and beyond. The department seeks to understand fundamental physical, chemical, and biological processes that define the origin, evolution, and current state of these systems and to use this understanding to predict future states. The department comprises 41 faculty (including two with a primary appointment in the Department of Civil and Environmental Engineering (CEE), one with a primary appointment in Engineering Systems Division (ESD), and another with a primary appointment in the Department of Aeronautics and Astronautics (Aero/Astro),) and more than 240 research staff, postdoctoral appointments, and visiting scholars.
EAPS is notable for its emphasis on interdisciplinary problems and is involved in numerous laboratories, centers, and programs that address broad questions in the Earth sciences, including those that are among the most pressing societal issues of our time: change in climate and environment, natural resources and hazards, and the origin and evolution of life on Earth and, perhaps, elsewhere. For example, the Earth Resources Laboratory (under directorship of Prof. Bradford Hager) integrates faculty, staff, and students across disciplinary, department, and school boundaries to investigate geophysical and geological problems in energy and resource development. The Center for Global Change Science (under directorship of Prof. Ronald Prinn) builds cross-institute activity in meteorology, oceanography, hydrology, chemistry, satellite remote sensing, and policy. The Lorenz center (founded in 2011 under directorship of Profs. Kerry Emanuel and Daniel Rothman) aspires to be a climate think-tank devoted to fundamental scientific enquiry. Furthermore, EAPS is MIT’s largest participant in the MIT-Woods Hole Oceanographic Institution (MIT-WHOI) Joint Program supporting its mission of graduate education and research in ocean sciences and engineering.
The EAPS faculty is committed to the development and maintenance of vibrant education programs at both the undergraduate and graduate level. The past year saw a major change in the way EAPS conducts oversight of these programs. The EAPS faculty voted to replace the Undergraduate Education and Graduate Education Committees with the Committee on the Education Program [CEP]. The CEP membership comprises the Associate Department Head, the Graduate Officer, the Undergraduate Officer, and the Education Officer. The new committee is in charge of regular oversight of teaching and student progress. The committee will create a specific taskforce, with membership from the broader faculty, for any special project that might arise. Student engagement with the education program is a continuing departmental goal. Students meet with the Department Head and Associate Head at least once per term to discuss concerns and issues arising in their respective programs with the goal of sustaining active and open conversation around educational issues.
EAPS has vigorous graduate educational programs in the areas of Earth, Planets, Climate, and Life, including geology, geochemistry, geobiology, geophysics, atmospheres, oceans, climate, and planetary science. In fall 2014, EAPS had 154 graduate students registered in the department, including 73 students in the MIT-WHOI Joint Program and three Fifth-Year Master’s students. Women constituted 41.6 percent of the graduate student population, and 5.8 percent were members of an underrepresented minority group.
The excellence of the EAPS graduate program is built not only on the strength of teaching and supervision by the faculty but also on the involvement of EAPS graduate students in departmental activities. Students develop formal and informal ways of improving their educational experience as well as the student life of the department. For example, the graduate students continue to take responsibility for an expanded orientation program for incoming graduate students. They plan a number of social events to introduce the newcomers to EAPS, MIT, and the Cambridge area. The department graduate students are well organized and meet regularly, with one student presenting his/her research to the student body at the weekly Graduate Student Seminar. Undergraduate majors are encouraged to attend these talks. The departmental Graduate Student Mentoring Program continues as a well-received approach to provide peer support for new students. In this past year, the graduate students expanded the program to provide a mentor to each EAPS senior.
EAPS awards an annual prize for excellence in teaching to highlight the superior work of its teaching assistants. During the 2015 academic year, Ms. Neesha Schnepf, Mr. Tom DeCarlo, Mr. David Wang, and Ms. Emily Zakem were recognized for their contributions.
Our students were also recognized by their respective professional societies. In April, 2015, Mr. Julien de Wit received the “ Prix Scientifique aux Jeunes de l’Association des Ingénieurs de l’Université de Liège 2014". At the 2014 Annual Meeting of the American Geophysical Union the Outstanding Student Paper Award was presented to Mr. Jean-Arthur Olive for his research on Mechanical and Geological Controls on the Long-Term Evolution of Normal Faults and Mr. Jörn Callies for his research on atmospheric and oceanic wave fluctuations. Mr. Sudhish Bakku received the Best Student Poster Paper presented at the 2014 Society of Exploration Geologists Annual Meeting for his research on Monitoring hydraulic fracturing using distributed acoustic sensing in a treatment well. Mr. Jared Atkinson was a member of the team that won this year's Caltech Space Challenge, a 5-day international student space mission design competition. Other student awards for AY15 can be found at http://eapsweb.mit.edu/news/2015/spring-newsletter-student-awards.
EAPS graduated a total of 24 doctoral students and six master’s students in AY15. Details can be found at http ://eapsweb.mit.edu/news/2015/degrees-awarded-2015.
In fall 2014, EAPS had 23 undergraduate majors, 87 percent of whom were women, and 13 percent of whom were members of an underrepresented minority group.
We note that the EAPS undergraduate population has always been small but that standard satisfaction is high and that we continue our efforts to increase the number of majors. These activities include events for incoming freshman, involvement through freshman advising and teaching beyond EAPS, widened use of social media, and increased visibility on campus. We again had a good number of freshmen choosing EAPS as a major, with ten new students joining us in fall 2015.
Beyond our own undergraduate program, the department maintains a strong presence in undergraduate education across MIT so that the general MIT student body has ready access to education in geo-scientific aspects of climate and environmental change, natural hazards, and natural energy resources. In addition to co-teaching classes cross listed with other departments in the School of Science and the School of Engineering, the department supports and provides leadership of two major undergraduate programs at MIT, Terrascope (under directorship of Prof. Samuel Bowring) and the Experimental Studies Group (under directorship of Prof. Leigh Royden). EAPS also offers a relatively large number of Freshman Advising Seminars. With the combined enrollment of Terrascope and the advising seminars, EAPS connected with 6.4 percent of the students in the freshman class on a weekly basis. Similarly, EAPS is an active participant in three interdisciplinary minor programs; the broadly based Energy Minor, the Astronomy Minor (with Physics) and the Atmospheric Chemistry Minor (with, Chemistry, Aero/Astro, and ESD).
At the 2015 Student Awards and Recognition Dinner, the Goetze Prize was awarded to Ms. Casey Hilgenbrink (advised by Prof. Kerry Emanuel) in recognition of her outstanding senior thesis. Ms. Molly Kosiarek (advised by Prof. Richard Binzel) received the W.O. Crosby Award for Sustained Excellence, recognizing her achievement, both academic and intellectual, as well as general contributions to the department. Ms. Madison Douglas and Ms. Judy Pu were the recipients of the EAPS Achievement Award, which recognizes a rising senior from across the EAPS disciplines. The award is presented to a student who has distinguished her or himself through a combination of high GPA, focused course work, and leadership within EAPS. Ms. Judy Pu was recognized as an outstanding undergraduate teaching assistant for her work with the students of 12.001 Introduction to Geology.
Beyond EAPS, Ms. Kelly Kochanski won the MIT International Science and Technology Initiative’s Suzanne Berger Award for Future Global Leaders for work in India during the past two summers. This included fieldwork in Ladakh, Pakistan (led by Profs. Benjamin Weiss and Oliver Jagoutz) and a research internship with Shell International.
EAPS graduated six bachelor degree students in AY15. Details can be found at http://eapsweb.mit.edu/news/2015/degrees-awarded-2015
The department continues in its efforts to hire the best young scientists and help them develop successful careers.
Geobiologist Dr. Gregory Fournier joined EAPS as a new Assistant Professor in July 2014. We are excited to have the opportunity to bring such talent into our department.
Dr. Kristin Bergmann, who received her PhD from Caltech and recently finished a Junior Fellowship with the Harvard Society of Fellows, joined our faculty as an Assistant Professor in July of 2015.
Dr. Timothy Cronin a former EAPS graduate and currently a postdoc at Harvard, has accepted our offer and will join our faculty in July of 2016.
We are now halfway through the forth year of the new junior faculty mentorship program introduced in January 2012. Each junior faculty is assigned a mentor team comprising a primary mentor (often a close colleague) and two senior faculty members from outside the candidate’s disciplinary group. They meet – as a group – once a semester and report to the Head of Department. Junior and senior faculty alike are satisfied with the new system, but feedback solicited from junior faculty will be used to make further improvements.
Promotions (Effective July 2015):
Assistant Professor of Geochemistry Shuhei Ono was promoted to the rank of Associate Professor with Tenure.
Associate Professor of Atmospheric Chemistry Colette Heald (joint CEE/ EAPS) was promoted to Associate Professor with tenure.
Assistant Professor of Engineering Systems and Atmospheric Chemistry Noelle Selin (joint ESD/ EAPS) was promoted to Associate Professor (without tenure.)
Honors and Awards:
Robert R. Schrock Professor of Geology Samuel A. Bowring was elected to the National Academy of Sciences.
Cecil and Ida Green Professor of Atmospheric Science Kerry Emanuel has been invited to give the Bjerknes Lecture at the Fall 2015 meeting of the American Geophysical Union. A paper [Aerts et al., 2014], (see also Faculty Research Highlights) of which he was a co-author, published last year, was awarded a prize by Lloyds of London.
Professor of Civil and Environmental Engineering and Earth, Atmospheric and Planetary Sciences Dara Entekhabi was elected a Fellow of the IEEE (Institute of Electrical and Electronics Engineers) for contributions to microwave remote sensing of soil moisture.
Professor of Oceanography Glenn Flierl was awarded the Henry Stommel Research Award of the American Meteorological Society “For fundamental insights into the dynamics of vortices and geostrophic turbulence and their impact on marine ecosystems.” He was also elected as a Fellow of the American Geophysical Union.
Associate Department Head and Cecil and Ida Green Professor of Geology Timothy Grove was awarded a Doctorat honoris causa de l'Universite de Lausanne. In addition Asteroid (9276) Timgrove (2014) was named in his honor in July 2014. He was inducted into the National Academy of Sciences in May 2015.
Professor of Physical Oceanography Paola Malanotte-Rizzoli has been honored with the Fellowship of the International Union of Geology and Geophysics (IUGG), Prague, 2015
Cecil and Ida Green Professor of Oceanography John Marshall has been invited to give the ‘ The Bernhard Haurwitz Memorial Lecture’ of the American Meteorological Society "For seminal contributions to atmospheric, oceanic, and climate dynamics and the creation of innovative modeling tools and educational resources."
Class of 1941 Professor of Physics and Planetary Science Sara Seager was elected to the National Academy of Sciences. She was also a 2015 recipient of an MIT Amer G. Bose Award which she plans to use to map biochemical space as she persues her search of life beyond Earth. Seager also received an honorary doctorate from the University of British Columbia.
Asteroid (9522) was named ‘Schlichting’ in recognition of Professor Hilke Schlichting’s work on the Kuiper Belt.
Ellen Swallow Richards Professor of Atmospheric Chemistry & Climate Science Susan Solomon received honorary doctorates from Brown University, and the University of British Columbia.
Cecil and Ida Green Assistant Professor of Geology Taylor Perron was awarded a James B. Macelwane Medal in recognition of “significant contributions to the geophysical sciences by an outstanding young scientist.” Perron was also made an AGU Fellow at the same AGU meeting.
Professor of Geophysics Daniel Rothman was elected as a Fellow of the American Geophysical Union.
Emeritus Professor Carl Wunsch has been selected as the 2015 recipient the Walter Munk Award of the Oceanography Society for “distinguished research in oceanography related to sound and the sea.”
Schlumberger Professor and EAPS Department Head Robert van der Hilst was elected to the American Academy of Arts and Sciences in October of 2014.
Throughout the term the EAPS calendar is crammed with events, lectures, and seminars, which are, in general, open to the public.
Notable community events during AY15 were the Carlson, Kendall, and Brace Lectures “Planets and Life”, a widely appreciated series exploring human and planetary perspectives on life on planet Earth, and the annual EAPS Fall Geology Fieldtrip.
The 4th Annual Carlson Lecture at the New England Aquarium, entitled “Big Cats, Panama and Armadillos: A Story of Climate and Life” was given by distinguished Craaford Prizewinner and former EAPS faculty member Peter Molnar. Molnar’s entertaining lecture explored what may have triggered the shift in climate that kicked off the cycle of ice ages Earth began experiencing three million years ago.
The 2nd Annual William Brace Lecture, “The Inference Spiral of Earthquake System Science”, was given by former EAPS’ Department Head, Thomas H. Jordan. Professor Jordan’s lecture highlighted efforts to develop and validate earthquake forecasting models based on the coupling of rupture and ground-motion simulators, focusing on how this modeling framework can be used to pose interesting questions of contingent predictability as physics problems in a system-specific context. Jordan is currently the W. M. Keck Foundation Professor of Earth Sciences at the University of Southern California.
Climate expert Jochem Marotzke delivered the 15th annual Henry W. Kendall Memorial Lecture co-sponsored with the Center for Global Change Science. In “Recent Global Temperature Trends: What do they tell us about anthropogenic climate change?” Marotzke discussed the apparent recent warming “hiatus” as well as the abilities and limitations of climate models. Marotzke, who currently serves as the Director of the Max Planck Institute for Meteorology in Hamburg, Germany, was a member of the EAPS faculty in the 1990s.
“Planets and Life”, the brain child of EAPS researcher Dr. Vlada Stamenković and Prof. Michael Follows, drew together experts both from within MIT and outside for a series of ten public lectures complemented by two panel discussions (hosted at the MIT Museum), to explore the grand environmental changes – from a natural planetary perspective – that might endanger the survival of the species Homo sapiens. The series was very well attended and drew a broad cross-institute audience of both students, and faculty, as well as the general public.
Open to the entire MIT community, each year the EAPS Fall Geology Field Trip provides an opportunity to participate in a two day tour of the geology of Central Massachusetts encompassing 200 million-year-old dinosaur footprints, lava flows and sandstones (some with fish fossils) deposited during the early stages of the rifting of North America from Africa, deposits of sand and gravel from melting glaciers, glacial lake deposits, and other evidence for starkly different past. The AY15 trip, led by Profs. Samuel Bowring, Thomas Herring, and Gregory Fournier, visited all the usual sites, camped overnight at Barton Cove, Gill, MA, and wrapped up with a fascinating curated tour of the Beneski Museum of Natural History at Amherst College, Amherst, MA, home of an enormous trove of Connecticut River valley dinosaur footprints.
The arrival of new Senior Development Officer, Angela Ellis, in July 2014, accelerated work to define and strengthen the EAPS “brand”. The communications team, headed by EAPS Communications Officer Helen Hill, has worked closely with Ms. Ellis to strengthen how research and fundraising news and opportunities are shared on the EAPS website and in our regular publications such as the renamed annual newsletter (EAPS Scope) and the biennial e-newsletter (EAPSpeaks.)
Other print materials were either updated or new materials developed to suit audiences at donor meetings and outreach events throughout the year, and plans are in place for a fresh suite of development materials in FY16 to both reflect the campaign and to convey EAPS four defining research themes: Earth, Planets, Climate, and Life.
Thanks to the talents of Ms. Jennifer Fentress, our in-house graphic designer, EAPS materials are now consistently attractive and professional, and reflect a unified and professional look that is recognizably “EAPS.”
EAPS social media audience continues to grow with the EAPS Facebook page, ably managed by Ms. Heather Queyrouze, providing a rich and vibrant open window on EAPS daily life and culture.
Significant projects during AY ’15 have included development of a new website (scheduled for launch in the fall of 2015) and commissioning of a short (5 minute) professionally produced promotional video (also due to be released in fall of 2015.) Both these initiatives were motivated by the continued perceived need to raise EAPS profile both within MIT, especially for the purposes of engaging more undergraduates, and externally among alumni and philanthropic communities, specifically in support of increasing graduate student fellowship and discretionary support.
The new website, a full-featured Drupal content management system based on a template developed by MIT's School of Science, will give EAPS the state of the art online tool it needs to efficiently and effectively recast its messaging.
The promotional video will be a vital tool in succinctly communicating the extreme relevance of the research and education taking place in the department.
FY15 has been a banner year for fundraising in EAPS, in large part because we were fortunate to receive four 7-figure gifts to establish new funds: namely, the Peter H. Stone and Paola Malanotte Stone Professorship Fund, the Norman C. Rasmussen Fellowship Fund, the Callahan-Dee Fellowship Fund, and the A. Neil Pappalardo Fund for EAPS. We also received seven other 6-figure gifts to support EAPS research and fellowship funds, including the Whiteman Fellowships, the J.H. and E. V. Wade Fellowship Fund, the Frederick A. Middleton (1971) Fellowship, a new EAPS Graduate Student Support Fund and major grants from the Simons Foundation for Origins of Life Research. New gifts and pledges to EAPS for FY15 totaled $13.45M, representing a 222% increase over FY14.
Our new Senior Development Officer, Angela Ellis, has focused fundraising energies on fellowships, meetings with alumni and friends, stewardship of major donors, and outreach events. In April 2015, we launched the EAPS Patrons’ Circle to celebrate donors who have given $70,000 or more towards endowed or expendable fellowships for EAPS graduate students. EAPS Visiting Committee member Neil Rasmussen '76, SM '80 graciously agreed to be the Founding Chair of the Patrons’ Circle and spoke passionately at the inaugural event about the importance of funding future leaders to act as trusted scientific advisors to government and industry partners, especially on societal issues such as climate change and natural hazards. 45 Patrons, students and faculty enjoyed the event, hearing compelling stories from four of our graduate fellows about their paths to MIT. Our first Madden fellow was also introduced to some of the leadership donors whose gifts had helped the Theodore Madden ’49 Fellowship Fund to reach its $1M threshold during the prior year.
In April, President and Mrs. Reif, Vice President for Research, Maria Zuber, and School of Science Dean Michael Sipser joined EAPS faculty and friends for a special reception held in the Ida Green Lounge to honor Emeritus Professor Peter H. Stone and Professor Paola Malanotte Stone (Rizzoli), and to celebrate their generous gift of a new professorship for EAPS. Other notable events for EAPS alumni and friends during the past year included the 4th Annual Carlson Lecture (community events.) Hosted by the Lorenz Center, and funded by John Carlson, this public lecture was attended by over 200 people, and was followed by a special dinner that provided opportunities to thank existing Lorenz Center and EAPS major donors and to meet potential new supporters.
Throughout the year, EAPS faculty members have been invited to lead tours with the MITAA travel program, and to give talks to MIT alumni in Denver, Palo Alto, Berlin and in Cambridge, at the Emma Rogers Society Annual Lunch and for the School of Science breakfast series. EAPS alumni and friends also had the opportunity to network and to meet Department Head Rob van der Hilst and other EAPS faculty at receptions held at the annual Society of Exploration Geophysicists and the American Geophysical Union meetings. Events such as these offer valuable opportunities for EAPS leaders and staff to meet with alumni and friends, to share news about the Department and to make helpful connections for future fundraising efforts.
The Senior Development Officer has also worked closely with colleagues in the School of Science and in MIT Resource Development during the past year to share news about EAPS research and current fundraising priorities (e.g. through regular meetings, the “Campaign Toolkit” etc.), and to foster awareness and excitement about EAPS research among MIT fundraisers, MIT alumni and new prospects. Discussions have been ongoing with fundraising colleagues about potential prospects for a proposed new EAPS Building, and a draft case statement has been prepared – in the hope that our building will become an institutional fundraising priority. Sustainability and climate research and education remain one of the areas of greatest interest to MIT alumni and friends, and in FY15 four gifts ($4.6M in total) were directed for the support of graduate students focused in these important areas. We are confident that as EAPS research and faculty and student achievements in these and other areas become more widely known, and as MIT frames its response to the climate challenge, that philanthropic support for EAPS will continue to gain momentum.
Faculty Research Highlights
Professor Binzel is working with graduate student Ms. Alissa Earle while completing preparation for the July 2015 New Horizons mission to Pluto through the analysis of images received inbound on approach. These images are being used to examine Pluto for seasonable variations on Pluto using maps of Pluto Binzel made in the 1990’s as a basis for comparison.
In a project spanning EAPS and Aero/Astro, Binzel is overseeing the final assembly of the student-built Regolith X-ray Imaging Spectrometer (REXIS) instrument scheduled for launch in September 2016 aboard NASA’s OSIRIS-REx asteroid sample return mission.
During the past year, experimental work in Professor Bosak’s group (in collaboration with EAPS Professor Perron) has demonstrated the dependence of microbial ecology, morphology, and biogeochemical activity on sediment reworking and flow [Liang et al., 2014; Mariotti et al., 2014 a,b, submitted].
Her group has also described a previously unknown mechanism for microbially-mediated production of macroscopic sedimentary features in sand, including simple horizontal trails previously attributed to early animal locomotion and used to argue for the presence of moving macroscopic organisms as far back as the Paleoproterozoic [Mariotti et al., 2014b, submitted a,b].
Their studies of fossils preserved in carbonate rocks during a Snowball Earth event identified a new fossil that resembles some modern red algae [Cohen et al., in press].
A collaboration investigating the evolution of microscopic eukaryotes related the evolution of some testate amoebae to changes in the cycling of C and Si in the Phanerozoic [Lahr et al., submitted].
In collaboration with Prof. Roger Summons and postdoc Dr. Florence Schubotz, members of the Bosak Group studied phosphate-lacking lipids that are abundant in various oxygen deficient waters and sediments where phosphate limitation is not thought to be a major environmental stress. Results showed that sulfate reducing bacteria produce phosphate-lacking lipids when limited by phosphate [Shubotz et al., in prep.], thereby alleviating the requirement for phosphate in phospholipids.
During her sabbatical in Berkeley, CA, Bosak investigated various genes responsible for the synthesis of these lipids.
Cohen, P.A., F.A. Macdonald, S.B. Pruss, E.D. Matys, and T. Bosak, Fossils of putative marine algae from the Cryogenian glacial interlude of Mongolia, Palaios. (in press)
Liang, B., T.D. Wu, J.L. Guerquin-Kern, H. Vali, H.-J. Sun, M.S. Sim, C.-H. Wang, and T. Bosak (2014), Cyanophycin mediates the accumulation and storage of carbon in non-heterocystous filamentous cyanobacteria from coniform mats, PloS One, vol. 9, no. 2, doi: 10.1371/journal.pone.0088142
Mariotti, G., S.B. Pruss, R.E. Summons, S. Newman, V. Klepac-Ceraj, and T. Bosak, Where is the ooid factory? (submitted)
Mariotti, G., S.B. Pruss, T. Perron, and T. Bosak (2014), Microbial shaping of sedimentary wrinkle structures, Nature Geoscience, vol. 7, no. 10, pp. 736-740, doi:10.1038/ngeo2229
Mariotti, G., S.B. Pruss, X. Ai, and T. Bosak, An alternative origin for early animal trace fossils (submitted)
Mariotti, G., T. Perron, and T. Bosak (2014), Elongation of stromatolites through feedbacks between flow, sediment motion and microbial growth on sand bars, Earth and Planetary Science Letters, 397, 93-100, doi: 10.1016/j.epsl.2014.04.036
B. Clark Burchfiel
Professor Burchfiel continues to carry out geological research in China, Eastern Europe and Scandinavia.
Burchfiel, B. C., and R. Nakov (2014), The multiply deformed foreland fold-thrust belt of the Balkan orogen, Northern Bulgaria: Geosphere, v.11, no. 2, p. 1-28 doi:10.1130/GES01020.1
Professor Boyle’s group submitted a manuscript on the first-ever Pb isotope data from the Indian Ocean, where they showed that the surface layers have a distinctive isotope composition matching the anthropogenic aerosols from that region. They also showed a clear difference in isotopic composition throughout the entire water column between the Arabian Sea and the Bay of Bengal they attribute to isotope exchange with sinking crustal and anthropogenic particles. In the Southern Ocean sector, the isotopic composition was consistent with natural crustal Pb isotope values. [Lee et al.]
Completing almost two decades of research at the Hawaii Ocean Timeseries station, the Boyle Group submitted a manuscript containing the largest number of measurements of the essential ocean micronutrient iron ever gathered from a single site in the ocean, with resolution varying from one day to 15 years. There was as much variability in a week as there was throughout the entire duration of the record. [Fitzsimmons et al.]
Fitzsimmons, J.N., C.T. Hayes, S. al-Subiai, R. Zhang, P. Morton, R. Weisend, F. Ascani, and E.A. Boyle, Daily to decadal variability of size-fractionated iron and iron-binding ligands at the Hawaii Ocean Time-series Station ALOHA, Geochimica et Cosmochimica Acta (in press.)
Lee, J.-M., E.A. Boyle, T. Gamo, H. Obata, K. Norisuye, and Y. Echegoyen, Impact of anthropogenic Pb and ocean circulation on the recent distribution of Pb isotopes in the Indian Ocean, Geochimica et Cosmochimica Acta (in press.)
Professor Cziczo’s group is focused on atmospheric chemistry, specifically the interrelationship of particulate matter and cloud formation. The motivation for their work is that the formation and persistence of clouds is currently the foremost source of uncertainty in our understanding of climate. To reduce this uncertainty the Cziczo Group utilizes laboratory and field studies to elucidate how small particles interact with water vapor to form droplets and ice crystals. Experiments include using small cloud chambers in the laboratory to mimic atmospheric conditions that lead to cloud formation and observing clouds in situ from remote mountaintop sites or through the use of research aircraft.
Since joining MIT, Cziczo’s research has expanded to include studies of cloud formation on other planets. These include Mars, since clouds are critical in understanding that planet’s water cycle, and exoplanets, since clouds are critical for detection of surface features and, ultimately, their ability to support life.
In the past year the Cziczo Group completed and published 3 experimental studies broadly concerning the formation of clouds by various particles of atmospheric importance with a focus on those created by human activities.
While continuing past activities, the Cziczo Group also initiated several new studies. These included:
· Studies of possible cloud formation mechanisms around exoplanets and Mars,
· Development of new instruments for studies of clouds at field sites and from aircraft and
· A novel study to use atmospheric instruments to retrieve an aerosol record from ice cores.
Cziczo also took time during his Fall 2014 junior faculty leave to initiate a new project on determining the organic content of mineral dust aerosol, critical for understanding their radiative and cloud formation properties (during two months spent at NOAA in Boulder, CO), and a new joint project using femtosecond lasers to probe aerosol surfaces (during two months at Kahlsruhe Institute of Technology (KIT) in Karlsruhe, Germany, co-hosting an international workshop on aerosol chemistry.)
Research talks given in the past year:
D. J .Cziczo et al. “Combining Field and Laboratory Studies to Understand the Dominant Sources and Mechanisms of Cirrus Cloud Formation”, Juelich Research Center Atmospheric Science Seminar, Juelich, Germany, December, 2014 (INVITED).
D. J .Cziczo et al. “Understanding Cloud Formation Using Single Particle Mass
Spectrometry”, ETH-Zurich Institute for Atmospheric and Climate Science Atmospheric Chemistry Seminar, Zurich, Switzerland, December, 2014 (INVITED).
D. J .Cziczo et al. “Combining Field and Laboratory Studies to Understand the Dominant Sources and Mechanisms of Cirrus Cloud Formation”, ETH-Zurich Institute for Atmospheric and Climate Science Colloquium, Zurich, Switzerland, December, 2014 (INVITED).
D. J .Cziczo et al. “Understanding Cloud Formation Using Single Particle Mass
Spectrometry ”, Karlsruhe Institute of Technology Atmospheric Science Seminar,
Karlsruhe, Germany, November, 2014 (INVITED).
D. J .Cziczo et al. “Combining Field and Laboratory Studies to Understand the Dominant Sources and Mechanisms of Cirrus Cloud Formation”, Telluride Science Research Center, Telluride, CO, August, 2014 (INVITED).
Professor Emanuel and his research group continued several lines of research and initiated several others.
Graduate student Ms. Morgan O’Neill received her PhD for work on the atmosphere of Saturn which became the cover story of an issue of Nature Geoscience. O’Neill et al. (2015) argues that the recently discovered giant polar vortices on Saturn can be explained by the systematic poleward migration of the cyclonic members of convectively generated vortex dipoles that are strongly evident in Cassini images. O’Neill’s two-and-a-half layer model showed which non-dimensional parameter regimes are likely to give rise to such features, and predicts that we should not see them on Jupiter.
Graduate student Mr. Vince Agard and Prof. Emanuel continued studying how severe local storms, which produce damaging wind, hail, and tornadoes, respond to climate change.
New graduate student Ms. Diamilet Perez-Betancourt and Prof. Emanuel are beginning an exploration of the dynamics of spiral rainbands in hurricanes.
Aerts, C. J. H. J., W. J. W. Botzen, K. Emanuel, N. Lin, H. de Moel, and E. O. Michel-Kerjan (2014), Evaluating flood resilience strategies for coastal megacities, Science, 344, 473-475, doi: 10.1126/science.1248222
O'Neill, M.E., K.A. Emanuel, and G.R. Flierl (2015), Polar vortex formation in giant planet atmospheres due to moist convection, Nature Geosciences 8, 523-526, doi: 10.1038/ngeo2459
Note: A complete list of 2014-2015 references can be found at http://eaps4.mit.edu/faculty/Emanuel/publications/research_papers
Professor Evans’ group studies physical properties of rocks, including elastic and inelastic mechanical behavior and fluid transmissivity, at pressures and temperatures found in the Earth’s crust.
Recently, his group has investigated the physical mechanisms of inelastic deformation during rock creep; the interactions among fluids, mechanical loading, and permeability; and relations between inelastic deformation and chemical reactions.
Using techniques borrowed from solid-state device fabrication, graduate student Ms. Alejandra Quintanilla-Terminel marked rock samples with grids of titanium/gold and subsequently deformed them at temperatures between 400-700 °C and confining pressures of 200-400 MPa. Comparison of the grids before and after deformation allows strain to be mapped at a scale of 10 micrometers. Combining these measurements with electron-back-scattered diffraction observations and other optical and electron microsopy, the Evans Group are able to quantitatively determine the partitioning of inelastic strain among such mechanisms as twinning, grain-boundary sliding, and dislocation slip. Comparison with similar observations in naturally deformed rocks gives improved understanding of creep and localization in the Earth’s crust.
In another project, researchers Dr. Yves Bernabe and Dr. Ulrich Mok used rock physics experiments at reservoir pressures and temperatures to understand the changes in permeability of rock matrices and the transmissivity of joints during the flow of aqueous pore fluids and during rock fracture. These experiments are providing data that are important for such applications as carbon-dioxide sequestration, metamorphic alteration, and reservoir exploitation.
In a project led by Prof. Bradford Hager, Evans and co-workers are working with groups led by Profs. Herbert Einstein and John Williams (CEE), and Prof. German Prieto (EAPS) to investigate the evolution of rock properties during hydrofracture processes in tight reservoirs. The project uses laboratory experiments, micro-seismic observations, and numerical calculations to describe the changes in the rock mass at several spatial scales. The project is funded by Total.
Raffaele Ferrari and his group made significant progress on several lines of research.
Prof. Ferrari showed that the drop in atmospheric carbon dioxide concentrations during glacial climates are associated with changes in the ocean circulation. [Ferrari, 2014]
Together with postdoc Dr. Ali Mashayek, Ferrari showed that the waters that sink in the ocean abyss at high latitudes return to the surface along the continental shelves in weakly stratified boundary layers. This is in contrast to the textbook view that these waters come back to the surface uniformly in the open ocean. The new theory appears to be supported by radiocarbon observations and implies that the exchange of carbon between the surface and abyssal ocean is much faster that previously assumed. [Ferrari et al. submitted]
Together with graduate student Mr. Jörn Callies (see also graduate student awards), Ferrari studied dynamics of upper ocean fronts, which regulate the exchanges of heat and carbon between the ocean and atmosphere. [Callies et al., 2015]
Together with postdoc Mr. Alexandre Mignot, Ferrari used a combination of float measurements and numerical models to study phytoplankton blooms in the North Atlantic and their role in driving ocean carbon uptake.
Callies, J., R. Ferrari, J. Klymak, and J. Gula, (2015), Seasonality in submesoscale turbulence, Nature Communications, 6, doi: 10.1038/ncomms7862
Ferrari, R. (2014),What goes down must come up, Nature, 513, 179-180, doi: 10.1038/513179a
Ferrari, R., A. Mashayek, T. J. McDougall, and M. Nikurashin (2015), Turning ocean mixing upside down, J. Phys. Oceanogr., (submitted)
Professor Flierl has been reassessing the theory of mixing by eddies and turbulence using an exact formalism and providing examples which show in detail how it works for both dissolved substances, for substances which are changing via chemical or biological interactions. This research shows that eddies do not simply move, for example, phytoplankton from regions of high concentration to low ones, but may end up transporting them in directions which depend on where their predators are.
Researchers in the Flierl Group have also been examining a simple model of the coevolution of predators and prey, showing that it can produce “arms-races” in which the traits of the predator are changed to make them more efficient while those of the prey are changing to reduce their vulnerability. These are temporary and become “see-saws” wherein the predator shifts towards one kind of prey which then decays, while a different kind takes advantage of the reduced grazing pressure; the predator now shifts back. These are really changes in which species is dominant. After longer times and at higher resource levels, the system exhibits speciation with discrete types of organisms.
Flierl has also been working with a company, iGlobe Inc., which produces high resolution, portable, spherical displays for visualizing climate data and
models. Flierl’s involvement in the project is in coupling the spherical display with a second display for presenting other kinds of complementary information such as images of the vertical structure corresponding to the global horizontal maps pictured on the sphere.
Work is also underway to use the globes to directly visualize data stored in databases so that researchers or educators can generate as needed displays of geophysical data. This project has involved outreach events to schools, the New England Aquarium, and the Cambridge Science Festival.
Chen, R., G.R. Flierl, and C. Wunsch (2015), Quantifying and Interpreting Striations in a Subtropical Gyre: A Spectral Perspective, J. Phys. Oceanogr., 45, 387-406, doi: 10.1175/JPO-D-14-0038.1
Chen, R., S.T. Gille, J.L. McLean, G.R. Flierl, and A. Griesel (2015), A
Multiwavenumber Theory for Eddy Diffusivities and Its Application to the
Southeast Pacific (DIMES) Region, J. Phys. Oceanogr., 45, 1877-1896, doi: 10.1175/JPO-D-14-0229.1
Flierl, G.R. and N.W. Woods (2015), Copepod aggregations: influences of physics
and collective behavior, J. Stat. Phys., 158, 665-698, doi: 10.1007/s10955-014-1162-0
Goluskin, D., H. Johnston, G.R. Flierl, and E.A. Spiegel (2014), Convectively
driven shear and decreased heat flux, J. Fluid Mech., 759, 360-385, doi: 10.1017/jfm.2014.577
O'Neill, M.E., K.A. Emanuel, and G.R. Flierl (2015), Polar vortex formation in giant planet atmospheres due to moist convection, Nature Geosciences 8, 523-526, doi: 10.1038/ngeo2459
Professor Follows’ current research investigates global ocean cycling of carbon,
nitrogen, iron and other elements on seasonal to glacial-interglacial timescales. His group has a particular focus on the ecology of marine microbes and the cellular-scale physiological traits that govern their interaction with the environment and one another. Their tools are largely idealized theory and numerical simulations, but the group also employs analysis of significant data sets, seagoing observations and (collaboratively) laboratory culture studies.
This year the Follows Group:
· Developed the first global-scale simulations of mixotrophy (combining photosynthesis and predation) in the marine plankton, suggesting this lifestyle may dominate marine primary and secondary production.
· Developed a mechanistic, quantitative physiological modeling framework to describe key traits of microbial populations in ocean models, replacing current “black box” parameterizations. This biologically meaningful platform connects with tools from modern, cellular “Systems Biology”.
· Contributed modeling support for the interpretation of the TARA Oceans global survey of the microbial populations of the surface ocean; the first such on a global scale. The expedition identified unique microbial populations and biogeochemical signatures associated with Aghulas Rings in the South Atlantic. Follows’ Group models have provided an explanation for these features and a contextual support for the sparse observations. With their co-authors, Villar et al. (2015) suggests how the special environment of the rings “filters” the plankton communities passing from Indian to Atlantic basins.
Villar, E., G.K. Farrant, M.J. Follows, et al. (2015), Environmental characteristics of Agulhas rings affect interocean plankton transport, Science, Vol. 348 no. 6237, doi:10.1126/science.1261447
This was Gregory Fournier’s first year as Professor of Geobiology within the EAPS Department at MIT. There have been two appointments to his lab: Postdoctoral Associate Dr. Joanna Wolfe, and visiting graduate student Ms. Cara Magnabosco.
Professor Fournier’s current goals consist of continuing to establish his research group, recruiting postdoctoral associates, graduate students, and undergraduate students. Additionally, he is continuing to develop his lab’s main computational resource in his lab a new18-node bioinformatics computing cluster, housed at the Massachusetts Green High Performance Computing Center (MGHPCC), expanding the software and database resources available, and training personnel in its application.
Particular accomplishments include participation in several invited lectures and events:
· Prof. Fournier participated as a speaker and panelist in the MIT Museum Soap Box Series, “How to Make Life and Influence Planets”, which discussed the coevolution of planetary systems and life across Earth’s history.
· During IAP, Prof. Fournier also organized a special departmental seminar on the Origin of Life, inviting speakers with backgrounds in synthetic biology, prebiotic chemistry, computational biology, and evolution to present their current research and views on the subject.
· Prof. Fournier also represented MIT at the NASA/Smithsonian Early Earth Exobiology Workshop held at the Smithsonian Museum of Natural History.
· Finally, Prof. Fournier was involved in the development of a web-based educational tool with PBS/NOVA as part of the Life on Earth Project at Harvard University. The purpose of this tool (Evolution Lab) is to provide a series of games, where students construct evolutionary trees of organisms from biological data, in order to teach principles of evolution and Deep Time.
Fournier’s Lab was awarded a grant this year as part of the Simons Foundation Collaboration on the Origin of Life. The purpose of this five-year award is to use genome-based approaches to investigate a set of questions about early life evolution and the early Earth. These questions include four major aims, including reconstructing the history of the planetary microbial sulfur cycle, the origin of ancient protein families involved in establishing the genetic code, and calculating the evolutionary rate and divergence times for major groups of microbes, in order to establish their impact on the establishment of geochemical cycles.
During the spring semester, Fournier was co-instructor together with Prof. Roger Summons teaching 12.007 Geobiology: History of Life on. The curriculum was updated to include more detailed aspects of prebiotic chemistry, early life, genomics, and the evolutionary history of major groups of organisms.
Several research projects within Fournier’s lab were started this year, supported by departmental startup funds and in collaboration with research groups at MIT and other institutions:
· Dating the Tree of Life: Using computational techniques and genome sequence data, this project attempts to combine genomic, paleontological, physiological, and geological/geochemical evidence to calibrate the evolutionary histories of major groups of microbes, in order to estimate when they likely evolved, and how their metabolisms influenced the planetary system. So far, this project has focused on the history of Archaea, and Proteobacteria, the latter in collaboration with the Polz Lab in CEE. Important findings to date include evidence that many major groups of Proteobacteria likely evolved around the same time as the major lineages of multicellular animals, ~700-600 million years ago during a time of extensive glaciation events, and that one of the most important metabolic pathways on the planet, methanogenesis, likely evolved within Archaea very early in Earth’s history, around 3.4 billion years ago. Additional calibrations and the development of more precise models will continue to improve these dates, as well as reveal additional connections between microbial evolution and planetary change.
· Genomes and the Rise of Oxygen: This project, a collaboration between NASA Astrobiology Institute’s “Foundations of Complex Life” team at MIT, and the “Alternative Earths” team at UC Riverside, CA, together with Prof. Roger Summons and Postdoctoral Associate Dr. David Gold, investigates the history of the emergence and spread of oxygen-related genes across microbial lineages. Mapping the evolutionary histories of these genes using phylogenies based on genome sequence data reveals how and when major groups of microbes likely first encountered oxygen, and adapted to changing levels of oxygen across 2.5 billion years of planetary change. So far, important preliminary findings of this work include the detection of separate origins for many oxygen-related genes within the photosynthetic cyanobacteria, providing independent evidence that this group pre-dates the rise of oxygen in the atmosphere ~2.3 billion years ago. Similarly, it seems that many groups of oxygen-using Archaea that live in extremely hot ocean vent environments acquired oxygen-related genes fairly recently (within the last 800 million years), independently supporting hypotheses that the deep sea may have only become oxygenated during a later stage of Earth’s history.
Professor Grove and his students have completed the first comprehensive investigation of the melting behavior of the upper mantle beneath subduction zone volcanoes as a function of variable temperature, pressure and water content. Using this new dataset in conjunction with results from previous hydrous experimental studies, Grove’s team developed a model for estimating the amount of dissolved H2O and the melt generation temperature of a mantle-derived magma as a function of varying pressure. These new experiments provide the first quantitative characterization of the influence of magmatic water content of the composition of melts produced during melting in subduction zones. Since the continental crust is largely produced from crystallization of arc parental magmas like the ones produced in this study, the work is of importance for understanding how the Earth’s continental crust has been generated through time.
Behn, M.D., and T.L. Grove, Melting systematics in mid-ocean ridge basalts: Application of a plagioclase-spinel melting model to global variations in major element chemistry and crustal thickness, Geochem. Geophys. Geosystems (in press).
Collinet, M., E. Médard, B. Charlier, J. VanderAuwera, and T.L. Grove, Melting of the primitive Martian mantle at 0.5 – 2.2 GPa and the origin of basalts and alkaline rocks on Mars, Earth and Planetary Science Letters (in press).
Donnelly-Nolan, J.M., D.E. Champion, and T.L. Grove (2015), Late Holocene volcanism at Medicine Lake volcano, northern California Cascades, U. S. Geological Survey Scientific Reports (submitted).
Grove, T.L., and C.B. Till (2015), Melting the Earth’s Upper Mantle: Chapter 1, In Encyclopedia of Volcanoes, 2nd Edition, Sigurdsson, H.R., ed., Elsevier.
Mandler, B.E., J.M. Donnelly-Nolan, and T.L. Grove (2014), Straddling the tholeiitic/calc-alkaline transition: the effects of small amounts of water on magmatic differentiation at Newberry Volcano, Oregon, Contrib. Mineral. Petrol. 168: 1066, doi: 10.1007/s00410-014-1066-7
Mitchell, A.L., and T.L. Grove, Melting the H2O-undersaturated mantle: Origin of high MgO, high Mg# basaltic andesites and andesites, Contrib. Mineral. Petrol. (in press).
Teaching activities and institute service:
Professor Grove taught a graduate class, Thermodynamics for Geoscientists (12.480) and a Freshman Advising Seminar, Meteorite from Mars Kills Dog (12A03) in the fall. In the Spring he taught Structure of Earth Materials (12.108) and helped Prof. Leigh Royden by providing two lectures for 12.002. Grove led a seminar with Prof. Taylor Perron that prepared undergraduate and graduate students for a field trip to the Sierra Nevada and southern Cascades that will take place in August 2015.
Professor Grove continued as Associate Dept. Head and worked to improve the EAPS graduate and undergraduate programs. This year’s efforts included: developing a collaborative teaching in Geobiology with the Biology Department, implementing a new set of graduate admissions procedures, and working with the junior faculty on graduate and undergraduate teaching efforts. He continues to explore a joint educational efforts in the area of the Geobiology and the Environment with Biology and CEE.
Other service and community outreach:
The American Geophysical Union (AGU) has appointed Prof. Grove to be chair of the AGU Task Force on Privacy. Prof. Grove also serves on AGU’s Development Board.
Prof. Grove serves as Chair of the Joint Committee for Marine Geology and Geophysics in the MIT/WHOI Joint Program.
Prof. Grove was a member of MIT’s Innovation Deficit Committee chaired by Marc Kastner which produced a report entitled “The Future Postponed”. He participated by contributing a chapter on Space Exploration. The report is aimed at 2016 Presidential Candidates and makes the case that reduction in Federal funding is causing the US to fall behind in science and technology.
Prof. Grove continues as Executive Editor for Contributions to Mineralogy and Petrology, and serves as an Editor for the Proceedings of the National Academy.
Professor Hager’s research involves understanding dynamical processes in the interiors of the Earth and other rocky planetary bodies on spatial scales ranging from reservoirs to the whole Earth and time scales from the present to the age of the solar system. Most of his work focuses on the relationship between observations of surface deformation, pore fluid pressure changes, earthquakes, and geodynamical (or geomechanical) processes. Hager has expertise in tectonic earthquakes in regional fault systems, as well as deformation, gravity changes, and earthquakes induced by reservoir production. He also leads a new multidisciplinary investigation of the fundamentals of hydrofracturing.
Professor Hager’s most important current research focuses on two areas.
· The first significant effort is in developing a mission jointly sponsored by NASA and its Indian counterpart, ISRO, to fly a dual L- and S-band InSAR satellite dedicated to observing surface deformation, ice sheet motions, and above-ground woody biomass. This mission, now called “NISAR, will be the most advanced InSAR mission ever flown. Hager is co-chair of the NISAR Science Study Group, responsible for earthquake, hydrocarbon, and carbon sequestration applications. NISAR has just been given the go-ahead to proceed to Phase B.
· The second significant effort is devoted to understanding earthquakes induced or triggered by human activities, including hydrocarbon production, CO 2 sequestration, hydroelectric reservoirs, and pumping of aquifers. Hager’s group has carried out the first fully coupled poroelastic model of the tragic 2011 Lorca, Spain earthquake, demonstrating that the changes in Coulomb stress from pumping of a nearby aquifer likely triggered the event. Hager has participated in an industry-funded effort to assess triggering of past and future earthquakes in Italy associated with hydrocarbon production and wastewater injection and lead a project assessing how to minimize earthquake risks associated with production of natural gas in the Netherlands.
Professor Herring is using primarily global positioning system (GPS) data to develop geophysically based models of Earth deformations on global, regional, and local scales and changes in the rotation of the Earth. He is also using interferometric synthetic aperture radar to study small surface deformations and geodetic methods to study Earth’s gravity field.
The Herring Group is using high-precision GPS measurements in many different study areas, including over much of the southern Eurasian plate boundary and the western United States. Group members are investigating processes on time scales of years leading up to earthquakes, transient deformation signals lasting days to many weeks, postseismic deformation after earthquakes on time scales of day to decades, surface wave propagation during earthquakes using high rate GPS data and ice dynamics. All of these measurements have sub-millimeter to few millimeter precision.
The group is also monitoring and modeling human-induced deformations in hydrocarbon fields and on tall buildings, including the Green building at MIT.
Jha, B., F. Bottazzi, R. Wojcik, M. Coccia, N. Bechor, D. McLaughlin, T. A. Herring, B. H. Hager, S. Mantica, and R. Juanes, Reservoir characterization in an underground gas storage field using joint inversion of flow and geodetic data, International Journal for Numerical and Analytical Methods in Geomechanics, NAG-15-0034, (in revision.)
Ju B., D. Gu, T. A. Herring, G. Allende-Alba, O. Montenbruck, and Z. Wang (2015), Precise orbit and baseline determination for maneuvering low earth orbiters, GPS Solutions, GPSS-D-15-00050 (in revision.)
Stevens, L. A., M. D. Behn, J. J. McGuire, S. B. Das, I. Joughin, T. Herring, D. E. Shean, and M. A. King (2015), Greenland supraglacial lake drainages triggered by hydrologically induced basal slip, Nature, 522, 73–76, doi:10.1038/nature14480
Members of the Jagoutz Group continued their research on the formation and evolution of the continental crust.
Professor Jagoutz has been working in northeastern India in the Himalayan mountains, since ~ 2008 to unravel the history of the ocean that separated India and Eurasia before India-Eurasia collision. Jagoutz et al. (2015), co-authored with MIT colleague Prof. Leigh Royden, showed that their precollsional scenario, constrained from their field work, could explain the unusually fast drift velocity of India during its trajectory to Eurasia. Their numerical simulations indicated that the anomalous high drift velocity of India between 80-50 million years ago was the result of complex interactions between two subduction systems. The paper was highlighted in a News and Views article in Nature Geoscience and has been covered by MIT News and the wider media including, among others, the New York Times.
Graduate student Ms. Claire Bucholz completed her PhD work at MIT and has accepted a faculty position at University of Southern California.
Third year PhD student Mr. Benjamin Klein and Jagoutz are studying how magmatic processes in the deep crust of arcs form continental crust.
Incoming graduate student Mr. William Shinevar and Jagoutz will work on an algorithm to convert seismic properties to chemical compositions to better constrain the compositional variations in the lower continental crust.
Jagoutz, O., L. Royden, A. Holt, and T. Becker (2015), Anomalously fast convergence between India and Eurasia linked to double subduction, Nature Geo. 8, 475-478, doi: 10.1038/NGEO2418
Note: A complete list of 2014-2015 references can be found at http://eaps.mit.edu/faculty/jagoutz/Publications.html.
John Marshall and his research group continued several lines of research.
Professor Marshall’s collaborative project -- with Research Scientist Dr. David Ferreira and Profs. Alan Plumb and Susan Solomon -- on the climatic implications of the ozone hole, led to an important publication in the J. of Climate. The response of the Southern Ocean to a repeating seasonal cycle of ozone loss was found to comprise both fast and slow processes, rapid cooling followed by slow but persistent warming. This work may account for the observed increase in Antarctic sea ice over the past few decades, in contrast to declining Arctic sea-ice. [Ferreira et al., 2015]
Graduate students Mr. Yavor Kostov and Mr. Brian Green are progressing well with their theses. Kostov, who is studying the role of the ocean in transient climate change, expects to graduate by the end of 2015.
Ferreira, D., J.C. Marshall, C.M. Bitz, S. Solomon, and R.A. Plumb (2014), Antarctic ocean and sea ice response to ozone depletion: a two timescale problem, J. Climate, 28, 1206–1226, doi: 10.1175/JCLI-D-14-00313.1
Note: A complete list of recent publications can be found here
Professor McGee’s research continues to focus on understanding the response of precipitation patterns to past climate changes in order to offer insight into the sensitivity of the hydrological cycle to changing forcing and boundary conditions.
Two recent papers from his group – one led by his graduate student Ms. Elena Steponaitis and a second currently in press – use stalagmites from a Nevada cave to reconstruct past shifts from wet to dry conditions in the U.S. Great Basin. The records, anchored by high-precision uranium-thorium dating from his laboratory, document systematic relationships between high latitude conditions in the northern hemisphere and western U.S. precipitation. In both the current interglacial period and the penultimate interglacial, warming of the high latitudes is associated with pronounced drying recorded by Mg/Ca ratios recorded in the cave’s stalagmites.
Field work conducted this winter in northern Chile with graduate student Ms. Christine Chen laid the groundwork for studies of past precipitation changes in the Altiplano and Atacama region where Chen and McGee mapped and sampled ancient shorelines in hydrologically closed basins. Precise dating of these shorelines in McGee’s lab has now enabled him to confidently tie wet periods in the Atacama to northern hemisphere cool periods.
Other research investigates past and present fluctuations in windblown dust emissions from North African and East Asian deserts, offering insights into changes in continental aridity, atmospheric circulation, and dust-related climate impacts.
Albani, S., N.M. Mahowald, G. Winckler, R.F. Anderson, L.I. Bradtmiller, B. Delmonte, R. Francois, M. Goma, N.G. Heavens, P. P. Hesse, S. A. Hovan, K.E. Kohfeld, H. Lu, V. Maggi, J.A. Mason, P.A. Mayewski, D. McGee, X. Miao, D.R. Muhs, B.L. Otto-Bliesner, A.T. Perry, A. Pourmand, H.M. Roberts, N. Rosenbloom, T. Stevens, and J. Sun (2015), 12,000 years of dust: The Holocene global dust cycle constrained by natural archives, Climate of the Past 11, 869–903, doi: 10.5194/cp-11869-2015
Cross, M., D. McGee, W.S. Broecker, J. Quade, H. Cheng, and R.L. Edwards, Great Basin hydrological changes during the penultimate deglaciation: A speleothem trace element and stable isotope record from Lehman Caves, NV, Quaternary Science Reviews (in press.)
Hayes, C.T., J.N. Fitzsimmons, E.A. Boyle, D. McGee, R.F. Anderson, R. Weisend, and P.L. Morton, Thorium isotopes tracing the iron cycle at the Hawaii Ocean Time-series station ALOHA, Geochimica et Cosmochimica Acta (in press.)
Steponaitis, E., A. Andrews, D. McGee, J. Quade, W.S. Broecker, Y.-T. Hsieh, B. Shuman, S.J. Burns, and H. Cheng (2015), Mid-Holocene drying of the U.S. Great Basin recorded in Nevada speleothems, Quaternary Science Reviews, doi:10.1016/j.quascirev.2015.04.011.
Frank Dale Morgan
(1) the exploration for Potable River Water and Groundwater in the Island of St Lucia, (2) innovating new electronics and field deployment methodologies for Spectral induced Polarization and (3) electrochemical causes of earthquake inception.
Paul O'Gorman and his group have continued to investigate how the atmosphere behaves in different climates.
In a paper published in Nature, Prof. O'Gorman investigated heavy snowfall events in climate-model simulations and observations. An optimal temperature for heavy snowfall was shown to be a key factor for the behavior of snowfall in different climates. In particular, snowfall extremes were found to be less sensitive to climate warming as compared to seasonal snowfall accumulations in many cases. [O’Gorman, 2014]
Graduate student Mr. Michael Byrne received his PhD for thesis research on land-ocean contrasts in the climate system. Byrne’s research explains why the prevailing paradigm for the response of precipitation to climate warming -- wet-gets-wetter, dry-gets-drier -- is not applicable over land. [Byrne and O’Gorman]
Byrne, M.P. and P.A. O'Gorman, The response of precipitation minus evapotranspiration to climate warming: Why the "wet-get-wetter, dry-get-drier" scaling does not hold over land, Journal of Climate (in revision.)
O'Gorman, P.A. (2014), Contrasting responses of mean and extreme snowfall to climate change, Nature, 512, 416-418, doi: 10.1038/nature13625
Professor Ono and his research group continued several lines of research focusing on stable isotope geochemistry.
Graduate student Mr. Andrew Whitehill received his PhD on mass-independent sulfur isotope fractionation for research demonstrated its origin and link to historic stratospheric volcanic events. [Whitehill et al., 2015]
Ono’s Group have developed a novel laser spectroscopy instrument to measure doubly isotope-substituted methane (13CH3D) and used it to test origins of methane from diverse settings. With graduate students Mr. David Wang and Ms. Danielle Gruen, together with postdoc Dr. Eoghan Reeves, Ono published the initial results in the journal Science. The research was highlighted in MIT news and the wider media. [Wang et al., 2015]
Wang, D.T., D.S. Gruen, B.S. Lollar, K.-U. Hinrichs, L.C. Stewart, J.F. Holden, A.N. Hristov, J .W.Pohlman, P.L. Morrill, M. Könneke, K.B. Delwiche, E.P. Reeves, C.N. Sutcliffe, D.J. Ritter, J.S. Seewald, J.C. McIntosh, H.F. Hemond, M.D. Kubo, D. Cardace, T.M. Hoehler, and S. Ono (2015), Nonequilibrium clumped isotope signals in microbial methane, Science, 348, 428-431, doi: 10.1126/science.aaa4326
Whitehill, A.R., B. Jiang, H. Guo, H. and S. Ono (2015), SO2 photolysis as a source for sulfur mass-independent isotope signatures in stratospheric aerosols, Atmos. Chem. Phys.,15, 1843-1864, doi: 10.5194/acp-15-1843-2015
Note: A complete list of 2014-2015 references can be found at
J. Taylor Perron
Professor Perron and his group study the processes that shape landscapes on Earth and other planets. Their efforts are currently focused on understanding widespread patterns in landscapes, climate’s effects on erosion, and the landscapes of Mars and Saturn’s moon Titan.
Graduate student Ms. Kimberly Huppert, in collaboration with Prof. Perron and Prof. Leigh Royden, helped to resolve a controversy concerning the mechanisms that control how volcanic islands above mantle “hot spots” uplift and subside over millions of years. After assembling a dataset consisting of hundreds of uplift and subsidence rates for the Hawaiian Islands based on tide gauge records and ancient shorelines and coral terraces, they found that nearly all of the vertical motion of the various islands, from rapid subsidence of the Big Island of Hawaii to slight uplift of Oahu, is explained by loading of Earth’s lithosphere by the massive volcanoes themselves. [Huppert et al., 2015]
Dr. Giulio Mariotti, EAPS first W.O. Crosby Postdoctoral Fellow, collaborated with Prof. erron and Prof. Tanja Bosak to study how microbial processes shape sedimentary features in the geologic record. In a laboratory experiment conducted in repurposed fish tanks, they showed that “wrinkle structures” – widespread, millimeter- to centimeter-scale, ripple-like features preserved in sedimentary rocks – were probably created by wave transport of microbial mat fragments, making them early macroscopic evidence of life’s interaction with its physical environment. [Mariotti et al., 2014]. Mariotti received the Luna B. Leopold Young Investigator Award at the December 2014 AGU Annual Meeting.
In complementary work, MIT-WHOI Joint Program graduate student Mr. Jaap Nienhuis, postdoctoral researcher Dr. Justin Kao, and Prof. Perron published the first complete explanation for the spacing of sand ripples created by waves, like those commonly found at beaches around the world. [Nienhuis et al., 2014]
Huppert, K.L., L.H. Royden and J.T. Perron (2015), Dominant influence of volcanic loading on vertical motions of the Hawaiian Islands, Earth and Planetary Sci. Lett., doi: 10.1016/j.epsl.2015.02.027
Mariotti, G., S. Pruss, J.T. Perron and T. Bosak (2014), Microbial shaping of sedimentary wrinkle structures, Nature Geoscience, 7, 736–740, doi: 10.1038/ngeo2229
Nienhuis, J.H., J.T. Perron, J.C.T. Kao and P.M. Myrow (2014), Wavelength selection and symmetry breaking in orbital wave ripples, J. Geophys. Res., 119, 2239-2257, doi: 10.1002/2014JF003158
R. Alan Plumb
Professor Plumb and his graduate students have continued to investigate several aspects of stratospheric dynamics and, in particular, their impact on surface climate. Using a general circulation model graduate student Ms. Aditi Sheshadri has shown how wave forcing from the lower atmosphere determines not only the seasonal climatology of the stratosphere, but also its interannual variability. She has also shown how Antarctic ozone depletion impacts surface winds in the southern hemisphere. Using the same model, graduate student Mr. Erik Lindgren is investigating how even very high altitude perturbations associated with solar variability can lead to surface impacts.
The surface impact of stratospheric variability is most evident during spectacular events known as “stratospheric warmings.” One especially dramatic event occurred in January 2013 when the polar vortex split into two, a signal that was observable all the way down to the surface. Graduate student Mr. Andreas Miller has shown that, contrary to conventional wisdom, internal stratospheric dynamics were responsible for this split and, ultimately, for the surface impact.
Graduate student Ms. Marianna Linz is investigating how observations of trace gases can be used to quantify the overturning circulation of the stratosphere and, especially, how they might be used to validate model predications of an accelerated circulation in response to increasing greenhouse gases.
Germán A. Prieto
Professsor Prieto’s group is focusing on developing tools to analyze ever-larger earthquake datasets, both world-wide as well as local. The first graduate student in Prieto’s group (Mr. Manuel Florez) just passed the General’s exam. Florez has been working on techniques to better locate deep earthquakes. The method is adaptable and has the potential to locate smaller events that may help delineate the seismicity deep inside the Earth.
In collaboration with various students and postdocs, Prieto Group postdoc Dr. Piero Poli has worked to better describe the earthquake rupture of large deep teleseismic earthquakes. Results suggest a different behavior of these deep earthquakes compared to what is seen for the shallow events. This suggests that earthquake rupture of deep earthquakes may respond to a different physical mechanism than shallow ones. [Poli and Prieto, 2014]
In a continuation of this work, Prieto and Poli have submitted a paper to Geophysical Research Letters about a large earthquake in the Bucaramanga Nest, the highest concentration of deep earthquakes in the world. The observations they have made with both global stations as well as with local stations they deployed has allowed them to describe the rupture process with unprecedented detail. A similar approach was used to study a deep earthquake in the middle of the US. [Froment et al., 2015]
Florez, M., and G.A. Prieto (2015), Depth phases double-difference relocation of earthquakes at teleseismic distances, J. Geophys. Res. (to be submitted.)
Froment, B., P. Poli, and G.A. Prieto, An unusual deep intraplate earthquake, Geophys. Res. Lett. (to be submitted.)
Poli, P., and G.A. Prieto (2014), Global and along-strike variations of source duration and scaling for intermediate-depth and deep focus earthquakes, Geophys. Res. Lett., 41., doi:10.1002/2014GL061916
Poli, P., G.A. Prieto, C. Yu, M. Florez, G. Chen, D. Mykesell, and H.A. Denzel, Increasing Radiation Efficiency with Time Points to Thermal Instability as the Mechanism of Intermediate-Depth Earthquakes, Geophys. Res. Lett. (submitted.)
Ronald G. Prinn
Professor Prinn reports that the Center for Global Change Science (CGCS; http://cgcs.mit.edu), its Joint Program on the Science & Policy of Global Change (JPSPGC; http://globalchange.mit.edu) and its Advanced Global Atmospheric Gases Experiment (AGAGE; http://agage.mit.edu), which he directs, produced over 70 peer-reviewed scientific papers in the past year. Details of these many accomplishments are available at these three websites.
Five new federal grants and five new industry donors have joined as sponsors of the work, and research spending continues at about $9.5M annually.
The AGAGE network has expanded into Africa with the first set of greenhouse gas and climate instruments are now operating in the new Rwanda Climate Observatory. This work involved EAPS doctoral candidate Mr. Jimmy Gasore.
Also the first high frequency measurements of the isotopic composition of the greenhouse and ozone-depleting gas nitrous oxide, have begun at the Ireland AGAGE station. This work involved EAPS doctoral candidate Mr. Michael.
Professor Paola Rizzoli and her collaborators, Research Scientists Drs. Jun Wei, Pengfei Xue, Danya Xu and Haoliang Chen, have continued their research on the South China Sea and Indonesian Through Flow reconstructing the climate and circulation of the basin over the four decades 1960-2000, emphasizing local climate changes in the strait and shelf adjacent to Singapore that show considerable warming. Numerical simulations have successfully reproduced this warming, which has considerable implications for the local ecosystem and the fisheries of the coastal waters. [Xu and Malanotte-Rizzoli, 2013; Chen, Koh, Malanotte-Rizzoli and Guiting, 2014]
Professor Rizzoli’s second major focus has been the collaboration with Prof. Eltahir’s group (CEE) in the coupling of Rizzoli’s ocean model with Eltahir’s atmospheric model for simulations of the present climate of the South East Maritime Continent. The two-way coupling has been successfully completed and the results compared with the available oceanographic and atmospheric climatological observations. [Wei et al., 2013] The investigation has also been successively been extended to the seasonal and intra-seasonal variability. [Wei et al, 2014]
Finally, negative feedback mechanisms between the atmosphere and the ocean have been identified which correct for negative/positive biases in oceanic/atmospheric variables. [Xue et al, 2014].
Chen, H., T.-Y. Koh, P. Malanotte-Rizzoli, and S. Guiting (2014), The relative importance of the wind-driven and tidal circulations in the Malacca Strait, Con. Shelf Res., 88, 92-102, doi: 10.1016/j.csr.201.07.012
Wei, J., P. Malanotte-Rizzoli, E.Eltahir, P.Xue, and D. Zhang, (2013), Coupling of a Regional Atmospheric Model (RegCM3) and a Regional Oceanic Model (FVCOM) over the Maritime Continent”, Climate Dynamics, Volume 43, Issue 5-6, pp 1575-1594, doi: 10.1007/s00382-013-1986-3
Wei, J., D. Wang, P.Malanotte-Rizzoli, and M. Li (2014), Coupled seasonal and intra-seasonal Variability in the South China Sea, Climate Dynamics, Volume 44, Issue 9-10, pp 2463-2477, doi: 10.1007/s00382-014-2250-1
Xu, D., and P. Malanotte-Rizzoli (2013), The Seasonal Variation of the Upper Layers of the South China Sea (SCS) circulation and the Indonesian Troughflow (ITF): an Ocean Model Study, Dyn. Atmos.Oceans, 63, 103-130, doi: 10.1016/j.dynatmoce.2013.05.002
Xue, P., E. Eltahir, P.Malanotte-Rizzoli, and J.Wei (2014), Local feedback mechanisms of the shallow water region around the Maritime Continent, J. Geophys. Res., 119, doi: 10.1002/2013JC009700
Professor Rothman has initiated a new project aimed at developing understanding of the stability of the Earth system -- the physical environment and the life it supports. Each of the great mass extinctions in Earth history are coincident with strong perturbations
of Earth's carbon cycle. Yet many such perturbations are not associated with mass extinction. What makes them different? Preliminary results, both empirical and theoretical, suggest the existence of a critical rate of carbon-cycle change beyond which mass extinction occurs. The results of this work should help inform our understanding of the long-term risks posed by modern environmental change.
Rothman's group also continues to develop a basic understanding of the ways in which the emergence of groundwater at the Earth's surface leads to channelized networks. A few years ago the group showed that such networks tend to ramify at angles of 2 pi/5 =
72 degrees. Recent work with postdoc Dr. Hansjorg Seybold shows that this prediction holds wherever climates are sufficiently humid, thus establishing a quantitative connection between the geometry of landscapes and the climate in which they form.
Professor Leigh Royden’s work focuses on understanding the large-scale processes in the crust and mantle that control the regional deformation of active tectonic systems, and, more recently, the global processes that organize plate tectonics.
Royden has worked on a wide variety of sedimentary basins because the vertical motion at the Earth’s surface contains important information that constrains processes within the lithosphere.
Royden’s main geographic areas of study are the Tibetan plateau, the Himalaya and Tibet, although she has worked on topics in a variety of other regions. Through this work she has demonstrated, among other things, the functioning of coupled thrust belt and back-arc tectonic systems, anomalous and rapid removal of mantle lithosphere during extension, the surface expression of slab pull in continental systems and its control on the regional processes of mountain building, lateral flow of deep continental crust on a scale of hundreds of kilometers, the thermal and metamorphic histories of a variety of orogenic systems, and the role of double subduction in driving rapid plate convergence.
Royden’s most significant work over the last year, which has occupied virtually all of her research effort, has been establishing an analytical technique for handling multiple subduction systems. The first results are reported in a paper with Prof. Oliver Jagoutz and others. Jagoutz et al, 2015, shows that the anomalously rapid motion of India relative to Eurasia, can be nicely explained from the documented history of subduction, which includes double subduction, and by the timing of arc-continent collisions that occurred east and west of India just prior to the onset of rapid convergence.
The double (and can easily be more) subduction method is currently being applied to examining various general geometries of double subduction. Comparison to numerical models is being carried out by Prof. Thorsten Becker of the University of Southern California (USC). The Becker Group is exploring how the method can be applied to multiple subduction systems on a sphere, which will make it possible to examine the organizing principles of global plate systems. This is particularly exciting, because the analytic method is so fast compared to the numerical methods (for one example run for 10 m.y., the analytical method takes 1.5 seconds on a standard laptop, the same experiment using the numerical method takes three days on a super-computer).
Jagoutz, O., L. Royden, A. Holt, and T. Becker (2015), Anomalously fast convergence between India and Eurasia linked to double subduction, Nature Geo. 8, 475-478, doi: 10.1038/NGEO2418
Hilke Schlichting’s research focuses on planet formation theory, extrasolar planets and solar system dynamics. She studies the solar system, since it is the only place where we can examine the outcome of planet formation in detail and uses the diversity and statistical properties of extrasolar planets to test planet formation theories. Her research over the past year has focused on understanding the formation of a new class of planets discovered by the Kepler Space mission, bodies that are typically several times more massive than the Earth but that orbit their host stars well inside the orbit of Mercury. Understanding the origin of this new and very ubiquitous class of planets is crucial for determining the key processes of planet formation and for assessing the suitability of these bodies to harbor life. Schlichting’s recent work has demonstrated that migration of either fully-formed planets or of solids in the proto-planetary disk must have played a key role in their formation. [Schlichting, 2014]
Together with her graduate student Mr. Niraj Inamdar, Prof. Schlichting also investigated atmospheric mass loss due to giant impacts that likely took place in the final assembly stage of these close-in exoplanets, showing that atmospheric mass loss was significant and that initial planetary atmospheres were likely much more massive than observed today. [Inamdar and Schlichting, 2015]
Inamdar, N.K. and H.E. Schlichting (2015), The Formation of Super-Earths and Mini-Neptunes with Giant Impacts, Monthly Notices of the Royal Astronomical Society, 448 (2):1751-1760, doi: 10.1093/mnras/stv030
Schlichting, H.E. (2014), Formation of close in Super-Earths & Mini-Neptunes: Required Disk Masses & Their Implications, Astrophysical Journal Letters, 795, 15, doi:10.1088/2041-8205/795/1/L15
Sara Seager’s main research focus is on exoplanet atmospheres and biosignature gases, gases that could be observed in the future in exoplanet atmospheres that might be attributed to life.
Professor Seager is involved in the search for exoplanets and her focus this year has been on two future space missions:
The first is the NASA “Probe-Class” Starshade study Seager chaired for two years ending in March 2015. The Starshade team comprised individuals from academia and NASA centers with a design team from JPL. The Starshade is a specially shaped screen tens of meters in diameter that would fly in space at tens of thousands of km from a space telescope with the goal to block out starlight so that an orbiting plant would be visible in reflected light. The ultimate goal is to be able to image Earth-size planets orbiting Sun-size stars, and a few such planets would be discoverable with a Starshade and small telescope. The report is at http://exep.jpl.nasa.gov/stdt/Exo-S_Starshade_Probe_Class_Final_Report_150312_URS250118.pdf
Seager also co-chaired a two year study that ended in July 2015 on the “High Definition Space Telescope” (HDST). Such a telescope would come after the Starshade mission and would be the largest space telescope ever launched for astronomy, with an aperture diameter of 12 m. HDST would be capable of searching hundreds of sun-like stars in a direct imaging search for planets down to Earth size, with an anticipated yield of dozens of terrestrial planets and the revolutionary capability to observe down to a spatial scale of 100 pc (parsecs) at all distances. The report was initiated and sponsored by AURA (Association of Universities for Research in Astronomy.) The report can be downloaded here http://www.aura-astronomy.org/news/hdst.asp
Seager is also a leading co-investigator on the MIT-led NASA Mission TESS (Transiting Exoplanet Survey Satellite, PI George Ricker of Kavli), scheduled for launch in 2017. Her responsibility is to help plan and run the MIT TESS Science Center which will deliver light curves to the community as well as internally by the TESS Team for the best planet candidates for follow-up mass and atmosphere measurements. The MIT-led NASA TESS mission (launch 2017) combined with the James Webb Space Telescope (launch 2018) will provide the first opportunity to search for life in atmospheres of rocky exoplanets.
Seager, S. and W. Bains (2015), The search for signs of life on exoplanets at the interface of chemistry and planetary science, Science Advances, Vol. 1, no. 2, e1500047, doi: 10.1126/sciadv.1500047
Her research group published several papers on exoplanets, habitability, and biosignature gases:
Hu, R.Y. and Seager, S. (2014), Photochemistry in terrestrial exoplanet atmospheres III. Photochemistry and thermochemistry in thick atmospheres on super Earths and mini Neptunes, Astrophysical Journal, vol. 784, no. 1, doi:10.1088/0004-637X/784/1/63
Kreidberg, L., J.L. Bean, J.M. Desert, B. Benneke, D. Deming, K.B. Stevenson, S. Seager, Z. Berta-Thompson, A. Seifahrt, and D. Homeier (2014), Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b, Nature, vol. 505, no. 7481, pp.
69–72, doi: 10.1038/nature12888
Seager, S. (2014), The future of spectroscopic life detection on exoplanets, Proceedings of the National Academy of Sciences of the United States of America, vol. 111, no. 35, pp. 12634-12640, doi: 10.1073/pnas.1304213111
Susan Solomon and her research group focus on atmospheric chemistry and its interactions with climate change, as well as on particulate matter produced in air pollution.
A recent paper published in Environmental Science and Technology provided game-changing new results on how the sensitivity of PM2.5 (aerosols smaller than 2.5 microns) to emissions of nitrogen and sulfur oxide pollution has changed since 2005, and has shown that over much of the American Midwest, nitrogen oxide controls could now reduce PM2.5 much more effectively than before, due to a regime shift in nonlinear chemical processes. PM2.5 is of particular importance due to its damaging impacts on human health, including death and respiratory ailments. [Holt et al. 2015]
Another recently published paper in Geophysical Research Letters has demonstrated that the influence of minor volcanic eruptions on climate change since 2000 have been greatly underestimated, due to the important role played by stratospheric particles at altitudes not generally sampled by satellite data used to estimate their abundances. This paper is of particular importance given the need to explain recent rates of change of atmospheric temperature, sometimes referred to as the ‘warming hiatus’. [Ridley et al. 2015]
Holt, J., N.E. Selin, and S. Solomon (2015), Changes in inorganic fine particulate matter sensitivities to precursors due to large-scale US emissions reductions, Env. Sci. & Tech., 49, 4834-4841, doi: 10.1021/acs.est.5b00008
Ridley, D.A., S. Solomon, J.E. Barnes, V.D. Burkalov, T. Deshler, S.I. Dolgii, A.B. Herber, T. Nagai, R.R. III Neely, A.V. Nevzorov, C. Ritter, T. Sakai, B.D. Santer, M. Sato, A. Schmidt, A., O. Uchino, and J. P. Vernier (2014), Total volcanic stratospheric aerosol optical depths and implications for global climate change, Geophys. Res. Lett., 41, 7763-7769, doi: 10.1002/2014GL061541
Members of Roger Summons’ Lab continued their studies of molecular and isotopic biosignatures from sediments, sedimentary rocks, environmental samples and microbial cultures. The overall aim of this work is to discern clues about the nature of early life on the Earth and the environmental transitions that permitted the development of complex life.
MIT-WHOI Joint Program graduate student Ms. Katherine French completed her research on the search for hydrocarbon biomarkers from 2.7 billion year old sediments [French et al., 2015], disproving some of her advisor’s prior work of 15-20 years ago.
Ms. Ainara Sistiaga, a student visitor from the Universidad de La Laguna, La Laguna, Spain, also successfully defended her thesis in the spring and published her work on the diet of Neanderthals based on studies of faecal sterols [Sistiaga et al. 2014, 2015].
Summons co-chaired a NASA study panel that defined contamination requirements for the Mars2020 mission and potential sample return [Summons et al., 2015]. He is spending the 2015-6 academic year as Cox Visiting Professor at Stanford University in the Department of Earth System Science in the School of Earth, Energy and Environmental Sciences.
French, K.L., C. Hallmann, J.M. Hope, P.L. Schoone, J.A. Zumberge, Y. Hoshino, C.A. Peters, S.C. George, G.D. Love, J.J. Brocks, R. Buick, and R.E. Summons (2015), Reappraisal of hydrocarbon biomarkers in Archean rocks, Proceedings of the National Academy of Sciences, 112(19), 5915-5920, doi: 10.1073/pnas.1419563112
Sistiaga, A., C. Mallol, B. Galván, and R.E. Summons (2014), The Neanderthal Meal: a New Perspective Using Faecal Biomarkers, PLOS ONE 9(6): e101045, doi: 10.1371/journal.pone.0101045
Sistiaga, A., R. Wrangham, Rothman, J., Summons R.E., 2015. New insights into the evolution of the human diet from faecal biomarker analysis in wild chimpanzee and gorilla faeces, PLoS ONE, 10(6): e0128931, doi: 10.1371/journal.pone.0128931
Summons, R.E., Sessions, A.L., Allwood, A.C., Barton, H.A., Beaty, D.W., Blakkolb, B., Canham, J., Clark, B.C., Dworkin, J.P., Lin, Y., Mathies, R., Milkovich, S.M., and Steele, A. (2014) Planning considerations related to the organic contamination of martian samples and implications for the Mars 2020 rover, Astrobiology, 14, 969-1027, doi: 10.1089/ast.2014.1405
Benjamin P. Weiss
Professor Weiss and his group are interested in the formation and evolution of the terrestrial planets and small bodies, with particular focus on planetary differentiation, paleomagnetism, meteoritics, and habitability. In the past several years, they have been studying the history of the lunar dynamo (Weiss and Tikoo 2014), the nature of planetesimals (Weiss and Elkins-Tanton 2013), and nebular magnetism in the early solar system (Fu et al. 2014).
Their most important work in the last year was to make the first determination of magnetic field strength in the planet-forming region of a protoplanetary disk (Fu et al. 2014). Obtaining such a measurement has been one of the defining goals of the field of extraterrestrial paleomagnetism since it was founded five decades ago and has major implications for the formation of terrestrial planets in the universe. Using newly developed experimental techniques, they demonstrated that chondrules in the Semarkona meteorite were magnetized in a substantial nebular magnetic field. Previous paleomagnetic experiments have been unable to isolate nebular magnetization while current astronomical observations cannot constrain the magnetic fields in the midplane of protoplanetary disks within several tens of AU of the star where planet formation occurs.
Their work holds broad implications for diverse disciplines. For the astrophysical community, magnetic fields are widely believed to play a critical role in protoplanetary disk evolution; their presence may explain the rapid redistribution of mass and angular momentum, the presence of turbulence, and the observed ubiquity of planet-forming disks. Their results offer, for the first time, direct constraints on the nebular field strength and therefore the importance of magnetic phenomena in protoplanetary disks. For the planetary science community, their identification of nebular magnetization in chondrules provides novel constraints on the mechanism and conditions of chondrule formation, a critical and hitherto enigmatic step in the evolution of solid bodies in planetary systems.
For the paleomagnetic community, their measurements represent the earliest recovered paleomagnetic record, the first paleomagnetic determination of non-planetary magnetic fields, the first in-depth paleomagnetic study of a new class of planetary materials, and the development of a suite of new microsampling and high sensitivity magnetometry techniques.
(*denotes current member of his research group):
*Fu, R. R., B. P. *Weiss, E. A. *Lima, R. J. Harrison, X.-N. Bai, D. S. Ebel, C. *Suavet, H. *Wang, D. Glenn, D. Le Sage, T. Kasama, S. J. Desch, R. L. Walsworth, A. T. Kuan (2014) Solar nebula magnetic fields recorded by the Semarkona meteorite, Science, 346, 1089-1092
*Weiss, B. P. and L. T. Elkins-Tanton (2013) Differentiated planetesimals and the parent
bodies of chondrites, Annu. Rev. Earth Planet. Sci., 41, 529-560.
*Weiss, B. P. and S. M. Tikoo (2014) The lunar dynamo, Science, 346, 1246753, doi:10.1126/science.1246753.
Professor Jack Wisdom has been studying the early evolution of the Earth-Moon system after the giant impact that is presumed to have formed the Moon. Isotopic similarities of the Earth and Moon suggest that the Moon-forming impact was more severe than previously thought, but this would leave the system with too much angular momentum.
Professor Wisdom and graduate student Mr. Zhen Liang Tian have recently found that the Earth-Moon system can be captured into a limit cycle associated with the evection resonance that removes the excess angular momentum. More work remains to be done.