Northern San Jacinto Fault – Mystic Lake Site (2009-2011)

This study was completed in 2011 as part of my master thesis project at San Diego State University. It took place in the San Jacinto Valley step-over, along the northern part of San Jacinto Fault in Riverside, California. In this study, we implement a remote- and field-based mapping techniques and analysis the Cone Penetrometer Test and paleoseismic trench data. The goal is to document paleoseismic evidence along this section of the San Jacinto Fault, estimate the Quaternary faults slip rate and evolution of this fault, as well as understand the kinematic relations between this fault and the San Andreas fault. Some results from this research has been published here and here. The map below shows the study area and the location of the Mystic Lake paleoseismic site.


Tom Rockwell (SDSU)
Nate Onderdonk (UCLB)
Sally McGill (UCSB)

Neotectonics of Java (2011-2016)

In this project, I use Java Island in Indonesia as a case study to understand how the overriding plate of a subduction zone deformed. The main component of this study consist of active faults and fold mapping. The overriding plate of Java has just a few active faults evidence because they are easily removed by the humid climatic system. However, these faults are important due to their proximity to the dense population of Java. To map the faults, I use combination of remote- and field-based geology and geomorphology mapping, quantitative geomorphology analysis, and paleoseismology. I then use the maps of active upper-plate structures, earthquake moment tensor data and stress orientation deduced from volcano morphology analysis to characterize the strain field of Java arc. Further, I use sandbox analog modeling to evaluate the mechanical factors that may be important in controlling the deformation.

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J Ramon Arrowsmith, Amanda Clarke, Kelin Whipple (Arizona State University)
Lisa Grant Ludwig (University of California Irvine)
Saad Haq (Purdue University)