"The Mechanism of CaCO3 Dissolution in Seawater and a Possible Way Forward on CO2 Sequestration"

Jess Adkins, Smits Family Professor of Geochemistry and Global Environmental Science, Caltech
Wednesday, April 25, 2018 - 4:00pm to 5:00pm

The dissolution of CaCO3 in the ocean water column and sediments is a fundamental control on the ocean’s alkalinity balance.  This process is also the main way the planet will take up anthropogenic CO2, though over tens of thousands of years.  We have been studying the basic kinetics of CaCO3 dissolution in the lab and in the field with a new method that is ~200x more sensitive than other approaches.  We can make measurements very close to equilibrium at saturation sates relevant for the real ocean.  I will show what we have learned about the physical chemistry problem of how dissolution works at the mineral-solution interface and the geochemical problem of how and where this reaction takes place in the ocean.  At the end I will say something about our efforts to scale the catalysis of carbonate dissolution with CO2 that we have discovered into a viable solution for fossil fuel sequestration in the ocean.

About the Speaker

I am a chemical oceanographer interested in using trace metals as tracers of environmental processes.  Most of my current work is centered around the geochemical investigation of past climates.  I am primarily concerned with the last few glacial/interglacial cycles that span a few hundred thousand years.  It is in this time range that we have both a relatively accurate and precise understanding of age models (though they are always improving) together with large climatic shifts that require mechanistic explanation.  In particular, we have an amazing record of the rapidity and magnitude of climate change from polar ice cores.

About this Series

Weekly talks given by leading thinkers in the areas of geology, geophysics, geobiology, geochemistry, atmospheric science, oceanography, climatology, and planetary science. Lectures take place on Wednesdays from 3:45pm in MIT Building 54 room 915, unless otherwise noted.