Much of my research is centered around cosmic-ray neutrons and applied cosmic-ray physics. My goal is to achieve a full understanding of cosmogenic isotopes and cosmic-ray neutrons, and my methods include field and laboratory measurements, modeling and theoretical work. The work on measuring and modeling of cosmic-ray neutrons started in the context of cosmogenic dating … Continued
I am a seismologist focused on interpreting seismic waves in terms of mantle structure, composition, and dynamics. Much of my research has centered on Earth’s core-mantle boundary region, a dynamic thermal and chemical boundary layer that separates the mantle and core convection systems. My group has primarily used seismic body waves from large earthquakes to … Continued
Fossil plants are extremely sensitive indicators of past climates, plant-insect interactions, biodiversity, and the effects of major environmental disturbances. These data provide deep-time analogs that uniquely illuminate modern ecosystems and their possible responses to anthropogenic change. I am a paleobotanist who studies the latest Cretaceous through middle Eocene, 67-45 million years ago (Ma), an interval … Continued
Our cross-disciplinary and collaborative research focuses on understanding geological processes in Earth’s deep interior, both on a regional scale – for instance, continental structure and evolution of Tibet, East Asia, and North America, the subduction of oceanic plates beneath western Pacific island arcs, the upper mantle transition zone beneath Hawaii, and the complex region just … Continued
My primary research areas are in theoretical & computational seismology. Research topics include surface waves, free oscillations, body waves, seismic tomography, numerical simulations of 3-D wave propagation, seismic hazard assessment, medical imaging, and nondestructive testing.
Reactions between Fe-bearing rocks and circulating waters power significant electron flow that can be harnessed for microbial metabolism and growth deep beneath the surface of the Earth. I am a geomicrobiologist who develops and apply x-ray scattering and spectroscopic approaches to interrogate the redox reactions that occur between mineral surfaces, microorganisms and fluids. My lab … Continued
My research program focuses on studying the three-dimensional deformation, throughout Earth’s history, of the Earth’s crust and mantle. The approach is quantitative and empiricial, using the rock record to determine the processes that have occurred or are occurring within the Earth. Research projects focus on a range of temporal and spatial scales, and on a … Continued
I am researching the thermo-chemical structure, dynamics and evolution of the interiors of solid planets and moons, including Earth, Venus, Mars, Mercury, Io and extrasolar super-Earths, focusing particularly on convection in the solid mantle and the associated dynamics of the lithosphere, which on Earth means plate tectonics. My main research tool is numerical simulation, using … Continued
Earth’s atmospheric circulation and its energy transport are essential for Earth’s habitability — past, present and future. Some of the most dramatic examples of the circulation’s influence include the abrupt seasonal increase of precipitation and reversal of trade winds that occur as part of the Monsoons and the seasonal migration of the storm track (region … Continued
My research focuses on three broad areas: (1) past warm climate change of the Paleogene and Eocene (approximately 60-50 million years ago (mya), including the Late Paleocene Thermal Maximum, an extreme warming “event” that occurred approximately 55 mya and lasted for only approximately 150,000 years, thought to be caused by a rapid input of carbon … Continued