COG3 Seminar: Blake Dyer (Lamont-Doherty Earth Observatory)
The geologic record of the last interglacial in the Bahamas
The islands of the Bahamas consist of carbonate sediments from the last interglacial period. These rocks contain the history of climate and sea level in a warmer world. Generally, the sediments form high elevation narrow ridges or lower lying marine flats. Historically, the ridges have been embroiled in controversy. Some authors have argued that these ridges are evidence of 'super storms' and a late interglacial rise in global mean sea level. I will show outcrop, elevation, and modern wind data that indicates the ridges are aeolian dunes. Then, to reconstruct the sea level history across the archipelago, an artificial neural network was used to map the aeolian and marine landforms. Lateral variations in the elevation of marine flats are the result of glacial isostatic adjustment. Comparisons of this elevation data to an array of glacial isostatic adjustment models provides important constraints to model uncertainties. This refined isostatic history is combined with core records of long term subsidence to make new estimates of global mean sea level from previously dated coral sequences in the region.
About the Speaker
Blake Dyer is a postdoctoral research scientist working at the Lamont-Doherty Earth Observatory of Columbia University, primarily with Maureen Raymo. The goal of his research is to better understand how sediments record the Earth-system response to changing boundary conditions. The information stored in the sedimentary rock record offers a broad range of past environmental variability that serves as a powerful baseline to differentiate naturally occurring change from human induced change and can reveal feedbacks that may become critically important in predicting future climate change. Dyer investigates this sedimentary record by merging modern data science tools and models with geospatial, geochemical and stratigraphic data collected over extensive field seasons.
About this Seminar
The Chemical Oceanography, Geology, Geochemistry, and Geobiology Seminar [COG3] is a student-run seminar series. Topics include chemical oceanography, geology, geochemistry, and geobiology. The seminars take place on Fridays from 10-11am in Building E25, Room 119, unless otherwise noted (term-time only).