GPS Seminars & Events

Geofluids at varying depths play fundamental roles in Earth's dynamic processes, from driving volcanism and hydrothermal eruptions to sustaining groundwater resources. Imaging and monitoring these fluids provide critical insights into tectonic processes, geohazards, and resource management. In this presentation, I will highlight several projects conducted by our group using temporary passive seismic geophone arrays to investigate geofluid dynamics across a wide range of spatiotemporal scales. At larger scales, we deployed seismic arrays across the Denali Volcanic Gap and Yellowstone to image magmatic structures and better understand crustal magma storage and transport. At smaller scales, we examined Yellowstone's hydrothermal systems, exploring how internal and external forcing mechanisms regulate the dynamics of eruptive features such as geysers and thumping hot springs. More recently, we have begun exploring how passive seismology can be applied in Utah, from mountain catchments to the Salt Lake Valley, to monitor groundwater systems and quantify their responses to seasonal hydrologic forcing, including snowmelt and evapotranspiration. Together, these studies demonstrate the versatility of passive seismic methods for imaging and monitoring geofluids across diverse geological environments and scales.

Global lakes and wetlands are significant natural sources of atmospheric methane. Arctic landscapes, which are currently warming 3-4x faster than the global average, have the highest density of lakes in the world. In the mid and high Arctic, lakes are largely thought to be well-mixed in the summer due to a short ice-free period and relatively cold summer temperatures that limit thermal stratification from developing. High-latitude northern lakes are thus largely considered to be the least vulnerable (of global lakes) to developing summer stratification over the coming century, although there are strongly conflicting projections on this point. Given that most observations over the last ~50 years demonstrate that mid and high Arctic lakes are well-mixed in the summer, and that there is sparse real-time monitoring of the stratification status of Arctic lakes overall, the contribution of Arctic lakes to ongoing and future methane emissions is highly uncertain and possibly vastly undercounted. This talk will discuss how biomarkers in Holocene paleorecords from mid and high Arctic Greenland lakes inform our understanding of lake summer mixing regimes during past sustained warming and whether summer stratification appears to be the exception or the rule when the Arctic warms.

Global lakes and wetlands are significant natural sources of atmospheric methane. Arctic landscapes, which are currently warming 3-4x faster than the global average, have the highest density of lakes in the world. In the mid and high Arctic, lakes are largely thought to be well-mixed in the summer due to a short ice-free period and relatively cold summer temperatures that limit thermal stratification from developing. High-latitude northern lakes are thus largely considered to be the least vulnerable (of global lakes) to developing summer stratification over the coming century, although there are strongly conflicting projections on this point. Given that most observations over the last ~50 years demonstrate that mid and high Arctic lakes are well-mixed in the summer, and that there is sparse real-time monitoring of the stratification status of Arctic lakes overall, the contribution of Arctic lakes to ongoing and future methane emissions is highly uncertain and possibly vastly undercounted. This talk will discuss how biomarkers in Holocene paleorecords from mid and high Arctic Greenland lakes inform our understanding of lake summer mixing regimes during past sustained warming and whether summer stratification appears to be the exception or the rule when the Arctic warms.

Geofluids at varying depths play fundamental roles in Earth's dynamic processes, from driving volcanism and hydrothermal eruptions to sustaining groundwater resources. Imaging and monitoring these fluids provide critical insights into tectonic processes, geohazards, and resource management. In this presentation, I will highlight several projects conducted by our group using temporary passive seismic geophone arrays to investigate geofluid dynamics across a wide range of spatiotemporal scales. At larger scales, we deployed seismic arrays across the Denali Volcanic Gap and Yellowstone to image magmatic structures and better understand crustal magma storage and transport. At smaller scales, we examined Yellowstone's hydrothermal systems, exploring how internal and external forcing mechanisms regulate the dynamics of eruptive features such as geysers and thumping hot springs. More recently, we have begun exploring how passive seismology can be applied in Utah, from mountain catchments to the Salt Lake Valley, to monitor groundwater systems and quantify their responses to seasonal hydrologic forcing, including snowmelt and evapotranspiration. Together, these studies demonstrate the versatility of passive seismic methods for imaging and monitoring geofluids across diverse geological environments and scales.

Atmospheric composition is shaped by complex interactions among emissions, transport,and chemistry, with important consequences for air quality, climate forcing, and emerging energy systems. Atmospheric observations from satellites, aircraft, and surface measurement networks provide a valuable window into these interactions, but they reflect the combined influence of emissions, transport, and chemistry. Models are therefore essential for connecting observed patterns to the underlying mechanisms that drive them. In this talk, I will show how global chemical transport modeling can be integrated with observations to better understand the drivers of atmospheric composition. I will present examples spanning interpretation of geostationary NO2 observations, investigation of atmospheric oxidant chemistry, and the implications of uncertainty in modeled oxidant concentrations for evaluating hydrogen's climate impact. Together, these studies demonstrate how integrating observations with atmospheric chemistry models improves our understanding of atmospheric composition across scales and supports more robust assessments of air quality and climate impacts.