A Comprehensive Analysis of the 1994 Java Tsunami Earthquake and Its Implications for our Understanding of Shallow Subduction Zone Dynamics and Source Processes

California Institute Of Technology, Pasadena CA

Investigators

Abstract

This project proposes to perform a detailed investigation of the 1994 Java earthquake and its larger aftershocks, by using seismsc waveforms and other geophysical and geological datasets. The 1994 Java earthquake was a large shallow subduction zone thrust-earthquake that was followed by a tsunami. Preliminary work shows a large discrepancy between the short period and long period behavior of the main shock in terms of moment rate and directivity. The aftershock sequence is highly unusual because of the normal faulting nature of almost all of its mechanisms, in contrast with the thrust main shock mechanism. By performing source inversions for the Java events, determining a detailed rupture model of the main shock, relocating aftershocks, investigating the origin of the aftershock pattern, and combining these seismic observations with tectonic datasets to develop a model of this unusual event, this project will be able to significantly enhance the understanding of how shallow subduction zones work.