CIRES Special Seminar: Adrian Borsa
Continuous GPS observations of crustal loading from hydrometeorological events on the scale of storms to drought
by Adrian Borsa - Institute of Geophysics and Planetary Physics at the Scripps Institution of Oceanography
Abstract: Recent studies using continuous GPS to estimate changes in terrestrial water storage point to a future where the global GPS infrastructure for monitoring crustal deformation can be leveraged for hydrological applications. Seasonal water and snow loading has long been known to generate an elastic earth response that is observable by GPS, but only recently have these signals been modeled to recover the underlying loads at local and regional scales. My work with colleagues at UCSD showed that GPS can be used to monitor subtle surface deformation due to the response of the hydrological system to drought, and to estimate the magnitude and spatial distribution of related water loss. I have recently extended this analysis to the continental scale and will show how GPS estimates of water fluxes by major watershed compare with predictions from land surface models and remotely-sensed gravity observations from GRACE. I have also narrowed the temporal range of this analysis to event-scale loading from individual storms and will illustrate the promise and challenges of applying GPS observations to these new higher-frequency hydrometeorological phenomena. Although focused on the hydrosphere, this work has implications for the use of GPS to study crustal deformation across the temporal spectrum, with relevance to geophysical problems such as seismic triggering and the fingerprinting analysis of vertical deformation.
Bio: Adrian Borsa is a researcher at the Institute of Geophysics and Planetary Physics at the Scripps Institution of Oceanography. His work aims to describe how the shape of Earth's surface is changing at timescales of seconds to decades, and to link observed change to geophysical processes associated with phenomena ranging from earthquakes to climate change. Dr. Borsa's expertise includes the collection and analysis of geodetic data from many sources, including permanent and mobile GPS sensors, airborne lidar, and satellite altimeters. He is also actively involved in the calibration and validation of elevation measurements from several generations of satellite altimeters, and has made the remote salar de Uyuni in Bolivia his field home for the past decade in support of this work.
Dr. Borsa took an atypical route to science, beginning with a B.A. in Government, an M.A. in International Relations, and an early career in international business focused on Japan and the United States. He received his PhD from the Scripps Institution of Oceanography in 2005, was posted at the US Geological Survey during his post-doc, and moved to Boulder, CO in 2008 to take a management position within NSF's EarthScope program. He returned to Scripps and to full-time scientific research in 2012.