Kaj JOHNSON

Institute Depertment of Geologial Sciences, Indiana University Title Researcher Country USA Period 2006/04/01 - 2006/04/30 Research Theme Modeling of post-seismic deformation based on rate and state dependent friction law using GPS data Host Researcher Shin'ichi MIYAZAKI

Self Introduction

Research Interests: Crustal deformation. Earthquake deformation. Postseismic relaxation. Fault friction. Geodetic studies.

I use geodetic data (GPS, triangulation, trilateration, InSAR) to infer deformation processes in the lithosphere. I am particularly interested in deformation associated with earthquakes and the earthquake cycle. My general approach is to begin with observations at the earth's surface (through geodetic data and field observations) and infer deformation processes at depth through mechanical models. Much of my research focuses on developing analytical and numerical mechanical models of deformation processes. My active projects include: 1) Postseismic deformation modeling at Parkfield, California and Denali, Alaska, 2) Estimating fault slip rates and lithosphere rheology in California and Tibet, 3) Earthquake cycle and mountain building in Taiwan, 4) Estimating fault frictional parameters.

At ERI I am working with Shin'ichi Miyazaki and Jun'ichi Fukuda (along with Paul Segall at Stanford and Kristine Larson at Colorado) on using 1 Hz GPS to model afterslip that occurs in the 24 hour time period after the 2004 Parkfield, California earthquake. We model slip on the fault with rate-state friction and compare model results with the GPS observations to estimate frictional parameters.