Recent spatiotemporal evolution of deformation in the Los Angeles Basin and southern Central Valley of California in the context of anthropogenic activity

Kyle D. Murray, & Rowena B. Lohman

Published August 15, 2018, SCEC Contribution #8688, 2018 SCEC Annual Meeting Poster #136

Southern California experiences ongoing crustal deformation associated with tectonic processes such as interseismic fault creep. However, anthropogenic activities, including subsurface fluid extraction, can result in widespread and even larger magnitude deformation signals. We analyze the recent spatiotemporal evolution of deformation in the southern Central Valley and Los Angeles Basin using GPS and Sentinel-1a/b SAR imagery (November 2014 - August 2018). In the southern Central Valley, subsidence associated with large-scale groundwater extraction for agricultural irrigation and municipal use reaches rates as high as 45 cm/yr projected into the the satellite line-of-sight (LOS) during the recent drought (2012 - 2017), with a pause or slowdown in some areas associated with the heavy precipitation in Spring, 2017. We find distinct modulation in seasonal and secular trends that correspond to a complex combination of anthropogenic and natural components of the water cycle. In the Los Angeles Basin, there are numerous fault-bounded and off-fault subsidence features related to fluid extraction reaching rates over 30 cm/yr in the satellite line-of-sight, as well as tectonic fault creep on the San Andreas, San Jacinto, and Elsinore faults with LOS rates of up to ~1 cm/yr.

Citation
Murray, K. D., & Lohman, R. B. (2018, 08). Recent spatiotemporal evolution of deformation in the Los Angeles Basin and southern Central Valley of California in the context of anthropogenic activity. Poster Presentation at 2018 SCEC Annual Meeting.

Related Projects & Working Groups
Tectonic Geodesy