Using InSAR and GNSS observations to investigate verical motions in the Valles Caldera, Northern New Mexico
— Savannah C. Devine, Eric Lindsey, Nathan Maier, Ronni Grapenthin, and Andrew Newman, [eds.]

Abstract—The Valles Caldera is a rhyolitic “supervolcano” formed during very large caldera-forming eruptions at 1.231 Ma and expelling
~400 km3 of ignimbrite, the Tshirege Member of the Bandelier Tuff (Goff, 2010; Nasholds and Zimmerer, 2022). Valles Caldera has a similar structure and composition as other large silicic calderas worldwide, including the Yellowstone and Long Valley Calderas. Understanding whether Valles is currently deforming will allow for a better understanding of any magmatic processes ongoing within the caldera. Here, we present an InSAR time series of the Valles Caldera using 37 interferograms from the Sentinel-1 satellite, spanning 2014 to 2022. We also present preliminary GNSS observations from a survey conducted in October 2022 and compare the results to surveys in 2002 and 2003 to estimate the cumulative deformation over a 20-year period. The InSAR and GPS results show a small signal within measurement uncertainty that broadly suggests subsidence within and around the Valles. We suggest that installation of a continuous GPS network would help better resolve deformation within the caldera and help isolate seasonal signals due to hydrology from signals due to long-term magmatic processes.