HR: 08:40h
AN: U31B-03    [Abstracts]
TI: A regional index approach to probabilistic modeling of extreme earthquakes
AU: * Thompson, E M
EM: eric.thompson@tufts.edu
AF: Tufts University, 113 Anderson Hall, Medford, MA 02155, United States
AU: Baise, L G
EM: laurie.baise@tufts.edu
AF: Tufts University, 113 Anderson Hall, Medford, MA 02155, United States
AU: Vogel, R M
EM: richard.vogel@tufts.edu
AF: Tufts University, 113 Anderson Hall, Medford, MA 02155, United States
AB: We discuss the application of extreme value theory to earthquake hazards. Recent innovations in flood frequency analysis provide a new perspective on the analysis of large earthquakes. Probability plot correlation coefficient hypothesis tests and L-moment goodness-of-fit evaluations reveal that the Gumbel (GUM) distribution provides a good approximation to the probability distribution function (pdf) of series of annual maximum (AM) earthquake magnitudes. Homogeneity tests based on the theory of L-moments further reveal that broad regions of the globe are homogeneous in the sense that the AM observations of earthquake magnitudes are well approximated by a GUM pdf with fixed upper moments. The homogeneity of global earthquake data across broad tectonic environments enables us to pool data into a regional pdf of earthquake magnitudes, termed an index earthquake distribution. Research in hydrology has shown that frequency analysis based on pooling of data using an analogous index-flood method are much more accurate than frequency analysis based on site or region specific data. The index earthquake distribution is a dimensionless GUM distribution with fixed scale parameter so only the mean earthquake magnitude must be estimated for a region to define the frequency distribution of large earthquakes. We show how the degree of spatial homogeneity of earthquake magnitudes across broad tectonic environments can be exploited to yield improved estimates of the risk posed by extreme earthquake magnitudes.
DE: 1817 Extreme events
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
SC: Union [U]
MN: 2007 Joint Assembly