My research focuses on earthquake sources and their consequences. My approach is to create new observational tools that help validate physical models. I use strong ground motion recordings to unravel the mechanisms that control the physics of earthquake ruptures. I use weak ground motions to decipher the effects of complex geological structure on seismic wave … Continued
I am a geobiologist interested in understanding how microbial dark matter contributes to biogeochemical cycling. These organisms are uncultivated and unclassified but constitute the vast majority of microbial life on Earth. My work is focused primarily on the deep subsurface environment, a large and geochemically interesting environment that is particularly rich in novel taxa. A … Continued
I specialize in developing new tracers for Earth system cycles. These tracers bring fresh perspectives to topics such as the chemistry and dynamics of the ancient atmosphere, biosphere productivity, and nutrient cycling. Improved empirical constraints on natural processes and Earth’s fundamental machinery may improve predictions of how the Earth system has operated in the past, … Continued
I study the connections between the evolution of Earth-system processes, biological innovation, and ecosystem change—foremost in Earth’s early history. My research integrates field, petrographic, and geochemical work. The protracted rise of oxygen over several billion years dramatically changed Earth’s surface environments. However, our current picture of Earth’s redox evolution is still painted with only broad … Continued
My research is aimed at understanding the physical and biological processes that have regulated biodiversity through time. Our lab studies the exceptionally rich and complete fossil record of marine invertebrates, and integrates field collections, geochemical observations, and statistical analyses to unravel the drivers of macroevolutionary change at a variety of timescales. A particular focus is … Continued
My research focuses on “molecular paleoclimatology” – the use of fossil lipids to reconstruct past climate change. Paleoclimate – the study of past climate change – informs us about the nature of climate change on Earth and helps predicts the effects of anthropogenic global warming. I use organic geochemistry, stable isotopic analysis, climate model output, … Continued
Through the processes of accretion, differentiation, and plate tectonics, the Earth formed a core, mantle and crust. For over 4 billion years, it has erupted lava, grown continents, recycled oceanic plates back into the mantle, and consequently built up internal structures that can be imaged using seismology. By analyzing massive datasets of ground vibration recordings … Continued
My research uses a combination of sea-going and satellite observations, numerical models and theory to study how variability in ocean circulation, acting over a range of spatial and temporal scales, influences Earth’s climate. Major themes of my research program include the ocean’s influence on Antarctic and Greenland ice sheet stability, air-sea exchange in sea-ice covered … Continued
My research uses records from ancient glacial ice to answer questions about the Earth’s climate system and past atmosphere. One main direction of our current research is reconstructing past carbon monoxide (CO) concentrations and isotopic composition. CO is a highly reactive gas and is a major sink of atmospheric hydroxyl radicals (OH), which serve as … Continued
My group’s research is on understanding dynamic processes that control the thermal and chemical evolution of terrestrial planets and Moon at different temporal and spatial scales. We develop analytical and computational models of thermal convection for planetary mantles. These models are used for not only understanding the physics of thermal convection but also interpreting geophysical, … Continued