Simulations of Strong Ground Motion of the 9.0 March 2011 Tōhoku Japan Earthquake Using a Finite Fault Simulator (FINSIM)
Nick C. Hamden
Iowa State University
FINSIM is a modeling program developed in FORTRAN that can be used to predict how a fault plane would react to an earthquake at a given magnitude and depth. FINSIM can also be used to map the likely finite fault movement of an earthquake after it has occurred, while at the same time calibrating the program to make better predictions in the future.
An earthquake is classified as having Strong Ground Motion when it is too strong for a normal seismometer to record accurately and generally they occur within 50 km of the Earth’s surface. The earthquake that occurred on March 11, 2011, was a 9.0 magnitude off the coast of Tōhoku, Japan at a depth of 35 km. Due to the location of the March 2011 earthquake, it is one of the better recorded seismic events in history. Over 1200 seismometers recorded usable data from the earthquake. Stations were eliminated from consideration for this experiment based on specific criteria: if the rock profile did not provide at least 30m of depth for the individual seismic station, if the class site indicated a ‘soil profile’, if the peak acceleration exceeded 200 gal, and if the station occurred more than 100~ km from the fault plane.
The main goal of the project is to use FINSIM as a way of mapping out the finite fault plane movements caused by the Tōhoku earthquake, and to calibrate FINSIM to make even more accurate predictions for large earthquakes in the future.
AAPG Search and Discovery Article #90182©2013 AAPG/SEG Student Expo, Houston, Texas, September 16-17, 2013