Phone: (650) 329-4897
e-mail: ijohanson@usgs.gov

Mailing address:
345 Middlefield Rd MS 977
Menlo Park, CA-94025

Ingrid Johanson

I spend my time trying to find out what’s happening under the earth’s surface on faults and in volcanoes.  I use measurements from GPS and Interferometric Satellite Radar (InSAR) of the deformation of the earth’s surface to infer (using a model) the characteristics of these sub-surface processes.

I am a currently a Mendenhall post-doc at the USGS, studying the deformation history of Kilauea and Shishaldin volcanoes. For this project, I am using persistent scatterers from satellite radar (InSAR); a method that extracts data from individual stable pixels embedded among noisy pixels. The method will provide denser data sampling than is possible with ground-based instruments (such as GPS) and will help constrain detailed models of magma movement in these volcanoes.

I also study aseismic slip on the San Andreas fault (SAF). This includes steady (interseismic) creep on the SAF near San Juan Bautista and accelerated aseismic slip following the Parkfield earthquake (postseismic slip). Aseismic slip is the product of a unique fault frictional regime that allows tectonic stresses to be released harmlessly. Understanding when this kind of slip occurs is important for fully understanding seismic hazard.