2024-2025: Geodesy: Kristine M. Larson

Kristine M. Larson
University of Colorado

Biography 

Kristine M. Larson is a geodesist. She was born and raised in southern California. She received a BA in Engineering Sciences from Harvard University in 1985 and a PhD in Geophysics from Scripps Institution of Oceanography, U.C. San Diego in 1990.

Her dissertation was one of the first to use the Global Positioning System (GPS) to measure the motions of faults in southern California. As a graduate student she also worked on the technical staff at the Jet Propulsion Laboratory.  She became an aerospace engineering professor at CU Boulder in 1990 and retired in 2018. With her CU Boulder colleagues, she has worked on a variety of GPS research projects, such as measuring deformation across the Nepal Himalaya, studying global plate tectonic speeds, synchronizing atomic clocks, and measuring soil moisture and snow depth.

Larson is an AGU Fellow and received the AGU Whitten Medal in 2020. In 2014, her research group received the Prince Sultan Bin Abdulaziz International Water Prize for Creativity for developing GPS Interferometric Reflectometry. She was awarded an Honorary Doctorate from Chalmers University of Technology in 2017. In 2020 she was elected to the National Academy of Sciences. She was a distinguished professor emerita at the University of Bonn from 2022-2024.

Abstract: GPS Can't Do That, Can It?

In this talk, Kristine M. Larson will summarize the “traditional” applications of GPS in geosciences as well as the new environmental applications her research group developed using GPS signals.
For many people, the Global Positioning System (GPS) is just one of those gadgets in a smart phone that makes our lives a little easier. Much less known to the general public is the way that GPS has revolutionized the geosciences. For decades, models have been able to predict how plate tectonics changes the surface of the Earth, but only with GPS have we been able to accurately measure these changes anywhere and anytime. Kristine M. Larson’s career has coincided with this GPS revolution. 
Early in her career Larson used GPS to measure fault motions at plate boundaries. Then, about 20 years ago, she began working on something GPS wasn’t supposed to be able to do¬: measuring how the ground is moving during an earthquake, when the ground is literally breaking apart. In trying to convert a system designed to measure slow tectonic speeds into a seismometer, she found herself spending most of her time trying to model the effects of reflected GPS signals so they wouldn’t contaminate GPS seismic records. However, intrinsically, these reflections provide information about the surface beneath the GPS antenna, i.e. how much snow is on the ground, whether the soil is wet or dry, or ocean tides.  This new technique, known as GPS Interferometric Reflectometry, is currently used throughout the world.