The research emphasis within the Department of Earth Sciences can be divided into four broadly defined groups. Our department encourages interdisciplinary interactions, and many of our faculty member’s interests span more than one discipline.
Volcanology, Petrology, and Geochemistry
The department has long enjoyed an international reputation for strength in studies of high-temperature geological processes, dating to at least 1965 when the original Center for Volcanology was established by emeritus faculty AR McBirney, DW Weill and GG Goles. The '60s, '70s, and '80s saw many landmark studies published by department faculty and graduate students on a variety of topics including characterization of the lunar samples returned by the Apollo missions; experimental studies of lava rheology, phase equilibria, and trace element partitioning; and field and analytical investigations of layered mafic intrusions, oceanic archipelagos, subduction-related volcanoes, ore deposits, and metamorphic terranes. Our current faculty continue the tradition of petrological and volcanological research while also expanding into the realms of geochemistry and geobiology. While our interests are diverse, we share a focus on active volcanic, magmatic, hydrothermal, and geomicrobial systems and fine-scale, process-oriented investigations.
Bindeman's principle focus is on understanding volcanic systems and his approach relies primarily on measurements of the stable isotopic (e.g., 16O/18O; D/H) compositions of phenocrysts and glasses in erupted products, both current and ancient. This work is done in his state-of-the-art laboratory which houses a MAT 253 multicollector stable isotope mass spectrometer, a laser fluorination extraction line, a high-temperature pyrolysis system, and an automated system for analysis of carbonates and waters. He is also a regular user of the Cameca IMS1280 ion probes at UCLA and University of Wisconsin which he uses to gather geochronological measurements and in situ isotope measurements. Much of Bindeman’s work centers on past supereruptions, including Yellowstone and Long Valley, but he also has studies underway on the products of recent and even current eruptions in Iceland and Kamchatka, and collaborative projects with others.
Dufek studies physical processes in planetary interiors, volcanic eruption dynamics, and multiphase flows that shape the landscape. His group is primarily focused on the application of fluid dynamics to understand mass and energy transfer in geological processes, with particular emphasis on volcanic systems. Most processes in nature involve multiple phases: for instance ash particles interacting with a turbulent gas carrier phase in an explosive volcanic eruption. One of the groups research goals is to delineate how multiphase interactions contribute to the structure and composition of planetary interiors, and the role of such interactions in determining the dynamics and deposit architecture of volcanic flows using computational, experimental and field studies. He uses high performance computing for calculations of magmatic reservoirs, turbulent gas dynamics and granular flows, and manages laboratory facilities that examine compressible fluid dynamics, granular mechanics and sensor design for extreme environments.
Giachetti is a volcanologist interested in understanding how volcanic eruptions evolve through time, especially the most explosive ones. He is studying in particular magma degassing and how it affects the dynamics of volcanic eruptions. Giachetti uses a range of field, laboratory and numerical modeling approaches, and oversees a textural laboratory that houses a helium pycnometer, a capillary flow porometer, a particle size analyzer and optical microscopes. Giachetti previously worked on Soufrière Hills Volcano at Montserrat but his recent work has taken him to our local Cascade volcanoes, including Medicine Lake and Newberry volcanoes.
Jin’s research focuses on how fast microbially driven geochemical processes proceed in natural environments and how the rates of these processes affect environmental chemistry. Current research topics include: (1) natural arsenic contamination in groundwater of the Willamette Basin, Oregon; and (2) abnormal redox chemistry in Upper Klamath Lake, one of the largest lakes in the western US. The groundwater project is to investigate how the close interactions between geochemical and microbial processes control the occurrence and attenuation of arsenic in groundwater; the lake project is to develop a new theory of geomicrobial kinetics to account for the impact of microbial diversity on the rates of biogeochemical processes. Both projects take a suite of multidisciplinary approaches, including field sampling and analysis, laboratory experiments, and numerical modeling.
Karlstrom studies fluid movements in and around volcanoes, glaciers, and bedrock landscapes. His volcanic interests include the eruption cycle, crustal magma transport, transitions in eruption style, volcanic seismicity, and the multiphase rheology of magmas. His glacial interests are primarily in glacial hydrology, mostly supraglacial stream morphodynamics. His landscape interests are in volcanic landscapes and the interactions between landscape construction through volcanism (both effusive and explosive), fluvial and glacial erosion. Karlstrom’s group develops analytic and numerical mathematical models for these processes, in combination with field measurements and laboratory experiments using analog materials.
The overarching goal of Polizzotto's research program is to help better predict, manage and respond to environmental contaminants that threaten human health. Contaminant distributions in soils, sediments and natural waters are controlled by a host of physical, chemical and biological processes, each of which can exert its influence over a range of spatial and temporal scales. Polizzotto's research integrates a suite of field, laboratory and spectroscopic approaches to better understand the sources, fate and transport of contaminants in the environment.
A primary interest of Reed’s is computer modeling of fluid/gas/mineral equilibria in high-temperature magmatic, volcanic, and fumarolic systems, using software of his own creation. His work is driven by field investigations and fluid inclusion measurements in systems ranging from ore deposits now hosted in old plutonic rocks, to encrustations forming today in modern geothermal systems. Recent work has taken him to a variety of field locales, including the giant porphyry copper deposit in Butte, Montana, and the active geothermal systems of Kamchatka and Iceland.
Wallace is primarily interested in volcanology and is an expert on volatiles in magmatic and volcanic systems. His lab houses a Fourier transform infrared spectrometer which he and his students use to measure pre-eruptive H2O and CO2 contents in trapped melt (now glass) inclusions in phenocrysts. They also use the electron microprobe, ion probe, and laser ablation ICP-MS to measure the concentrations of other volatiles (e.g., Cl, S) and trace elements. A major focus of Wallace’s group is in understanding the origins and role of fluids in subduction-related volcanism. Wallace’s field-based studies take him and his students primarily to the volcanoes of Mexico and the Cascades.
Watkins studies geological processes in high-temperature systems (magmas) as well as low-temperature systems (aqueous solutions). His group uses a combination of laboratory experiments, isotope measurements, and theory to understand how environmental variables (such as temperature, pressure, and chemistry) influence the shape and composition of crystals and bubbles. This information in turn helps geochemists, volcanologists, and oceanographers decode the information that is recorded in the geologic record. Watkins oversees the Experimental Petrology Lab as well as the new Isotope Geochemistry Clean Room Facility.
Geophysics and Geomechanics
The geophysics group performs research on problems that span a multitude of spatial and temporal scales. Research is focused on problems in solid Earth geophysics including mantle upwelling, convection, lithospheric structure, regional tectonics, earthquake mechanics, crustal deformation, ice physics, and geomechanics. Our faculty specialize in a number of techniques including seismology, analytic and numerical modeling, data analysis, inverse methods, and space geodesy.
Erickson conducts research in computational mathematics and physics, applied predominantly to problems in the natural sciences. Currently, Erickson develops high-performance methods for earthquake cycle simulations and volcanic eruptions. These projects are funded by the National Science Foundation and the Southern California Earthquake Center. Erickson co-leads the SCEC-SEAS (Sequences of Earthquakes and Aseismic Slip) code-verification project.
Hooft studies how magma is transported from Earth’s mantle to the surface at volcanoes and the interaction of mantle plumes with ocean ridges. Hooft also investigates the structures that control rupture segmentation at the Cascadia subduction zone. Hooft leads research expeditions to the Cascadia margin, oceanic spreading centers, and volcanic hotspots. Hooft collects and analyzes dense geophysical data and uses inverse modeling on high performance computers.
Humphreys works on upper mantle seismology, lithospheric dynamics, tectonics, and geodynamics.
Karlstrom works on problems in volcanology, petrology, geodynamics, glaciology, and geomorphology. Active projects include the eruption cycle, melt focusing and crustal thickening in arcs, the Columbia River Flood Basalts, landscape evolution in volcanic environments, supraglacial hydrology, unsteady behavior in volcanic eruptions, and the interpretation of volcanic seismicity. Karlstrom's research involves a combination of theoretical and numerical models, field measurements, and laboratory experiments.
Melgar is a seismologist and a geodesist and his lab's research focuses on large earthquakes. Melgar is most interested in the science behind these big events and what makes these them tick. By learning about their physics, Melgar's group aims to understand the hazards they produce which affect society, namely, strong shaking and tsunamis. With this basic knowledge,they take the extra step and work on the technology behind early warning systems to issue alerts in advance of these hazards. To pursue these interests, they observe and measure earthquakes and create models.
Paty is a planetary and space physicist specializing in studying moon-magnetosphere interactions and icy moon interiors with simulations and spacecraft observations. She is a co-investigator on NASA’s Europa Clipper mission and actively developing new mission strategies to explore the Neptune-Triton system as part of the Trident mission team. She currently sits on the steering committee of the Outer Planets Assessment Group and is also serving on a National Academies panel for the Planetary Science and Astrobiology Decadal Survey. She teaches and mentors students in planetary science.
Rempel's research is directed towards understanding the fundamental interactions that govern a broad spectrum of natural processes. Much of this work centers on the fluid mechanics, solid mechanics and thermodynamics that control interactions between solids and fluids, especially near the melting transition. Rempel is particularly interested in problems that span a range of length and time scales, often motivating the development of homogenized models to translate from the microscopic distances over which the controlling physical interactions operate, to the much larger scales at which their effects are observed. Current work is focused on solid-fluid interactions along faults during earthquakes and slow-slip events; the controls on glacier sliding that result in sediment entrainment and landscape evolution; the development of gas hydrate anomalies and their implications for submarine slope stability and pockmark formation; multiphase shear and transitions between distributed (viscous) and localized (frictional) deformation mechanisms, with application to fault mechanics and solidifying lava flows; segregation and transport processes during solidification and melting in porous media on Earth and Mars; and passive strategies for thermal storage and timed heat release in the built environment.
Sahakian studies a variety of things relating to seismic hazard. Some work focuses on source characterization, to image faults and understand the hazards they pose. Other work estimating ground-motion—from statistical models to numerical simulations—for constraining seismic hazard, as well as learning more about earthquake source processes.
Thomas is interested in the physical properties of faults, seismotectonics, crustal deformation, and the mechanics of earthquakes and faulting. Thomas's group uses a variety of tools, such as moment tensor inversion, waveform modeling, analysis of seismicity catalogs, and numerical models of fault friction to approach research questions.
Toomey's lab research focus is on tectonic plate boundaries and hotspots, where we have pioneered the use of ocean bottom seismology to study earthquake and volcanic processes. Toomey's group has led scientific expeditions in the Atlantic, Pacific, and Mediterranean oceans, the Galápagos Archipelago, and the Oman ophiolite. Study sites include spreading centers (e.g., East Pacific Rise, Juan de Fuca Ridge, Mid-Atlantic Ridge), hotspots (Iceland, Galápagos), continental volcanoes (Newberry, Oregon), and more recently subduction zones (Cascadia Initiative, Santorini Volcano). Toomey uses a wide variety of seismic methods (body and surface wave tomography, seismicity, ambient noise) and is actively developing imaging methods for strongly heterogeneous and anisotropic media. Toomey's research has been published widely in Nature, Science, Geology, Nature Geoscience, and specialty journals.
Stratigraphy, Structure, and Surface Processes
Research in these disciplines is aimed at understanding complex interactions among tectonic and climatic processes that drive landscape evolution, earthquake histories, basin filling, and deformation of the crust. We investigate these processes through detailed field studies combined with related tools such as geochronology, numerical modeling, isotope geochemistry, and GIS-based geospatial data analysis. Studies of surface processes examine how tectonics and climate affect the evolution of landscapes. Fieldwork, numerical simulation, topographic analysis, and experimental study of rivers, landslides, soils, glaciers, rainfall, and fire are used to study the movement of water and sediment over a range of spatial and temporal scales. Structural geology and neotectonics focus on application of modern field and analytical techniques to solving problems in Cenozoic tectonics and active faulting. Recent studies examine deformation in the Basin and Range province and coastal region of Oregon, active tectonics of the San Andreas Fault system, Cenozoic extension in Death Valley, and seismic risk along the Pacific margin of the US and in central Asia. Studies of sedimentary basins investigate the dynamic interactions among crustal subsidence, sediment transport, changing depositional environments, and active faulting and folding that govern these processes. Projects are focused on Neogene basins in Southern California and northwestern Mexico, and Mesozoic tectonics of eastern Oregon.
Dorsey’s research is focused on field studies of tectonically active sedimentary basins, with the goal of understanding the complex tectonic, stratigraphic, and geomorphic evolution of active regions. Integrated basin analysis informs us about the dynamic interplay between ancient fault systems that create basins, and the surface processes that fill them with sediment. Dorsey and her students are working primarily in two areas: (1) Miocene to Pleistocene sedimentary basins along the San Andreas plate boundary system in Southern California and NW Mexico; and (2) late Miocene to Pliocene sediments in SE California and SW Arizona, which record the initiation and early evolution of the Colorado River.
Miller uses detailed geologic mapping and small-scale structures to reconstruct the evolution of fault zones. She is particularly interested in the structural geology and tectonics of the Death Valley region as it pertains to crustal extension. Her most recent students and interests have focused on brittle faulting the Amargosa Chaos and brittle/ductile evolution of the turtlebacks.
Erosion sculpts landscapes in response to tectonic activity and climatic forcing. The focus of Roering’s research is on understanding how surface processes alter and transport bedrock and soil near the Earth’s surface. Understanding these processes is a critical prerequisite for analyzing how crustal dynamics, climate change, and land-use practices affect landscape morphology, sediment yield, and geologic hazard potential. Through field, remote sensing, experimental, and numerical investigations, Roering’s research group has embarked on a series of studies to explore how landscapes respond to various perturbations, such as storms, earthquakes, and fire. Their investigations have encouraged them to forge fruitful collaborations with geodynamicists, soil scientists, hydrologists, ecologists, climatologists, sedimentologists, and structural geologists among others, as surface processes operate at the interface of Earth’s lithosphere, biosphere, hydrosphere, and atmosphere.
Sutherland’s research group focuses on the zone where freshwater meets saltwater. These estuarine regions of the world hold vital importance to humans, both by acting as connections to the ocean for a majority of the world’s population, but also as regulators of global climate. In particular, Sutherland’s group has recently focused on ice-ocean interactions in the glacial fjords of Greenland, southeast Alaska, and the western Antarctic Peninsula, in addition to the movement and melt of large icebergs. Closer to home, his group works with a diverse range of scientists and stakeholders on understanding the circulation and sediment dynamics in Coos Bay, a small estuary in southern Oregon that hosts UO’s marine lab and a National Estuarine Research Reserve. Visit his website for more information.
Weldon’s research is primarily focused on problems in neotectonics and structural geology.
Paleontology
The University of Oregon has a long tradition of research on fossils and the evolution of life dating back to Thomas Condon, foundation professor of Sciences in the original 1876 faculty of six. Fossil horses he collected in Oregon were influential ammunition for Thomas Huxley during his visit to American collections in 1876, as material evidence for Darwin’s theory of evolution. The Condon Collection here at the UO has now been greatly expanded, most notably by Arnold Shotwell, and was ranked 13th in the nation in size and scientific importance by a 1977 NSF-sponsored survey. Work on fossil mammals continues to be a strength, with emphasis on small mammals and artiodactyls, as well as the study of fossil plants and soils. Fieldwork is currently active in Oregon, Nevada, California, Antarctica, Argentina, and Australia.
Davis is interested in the evolution and development of headgear in ruminant artiodactyls, changes in macroecology over time, and conservation paleobiology. Recently, Davis has described rare specimens of a Late Miocene field cat found in eastern Oregon and ankle bone variations in two species of pronghorn antelope from the Late Miocene fossil site, Thousand Creek, in Nevada. His current work focuses on the origin and evolution of horns and antlers on bovids, cervids, and giraffids.
Hopkins is primarily interested in examining paleoecology in the Oligo-Miocene of Oregon through the lens of rodent biostratigraphy. Current research activities include studying the levers in arms, legs, and heads of small mammals to understand the evolution of digging behaviours in these animals and investigating Late-Miocene evolution of dogs by describing canine fossils found in southeast Oregon’s Juntura Formation.