Scaling relations of seismic moment, rupture area, average slip, and asperity size for M∼9 subduction-zone earthquakes

Abstract

Scaling relations for seismic moment M0, rupture area S, average slip D, and asperity size Sa were obtained for large, great, and giant (Mw = 6.7-9.2) subduction-zone earthquakes. We compiled the source parameters for seven giant (Mw∼9) earthquakes globally for which the heterogeneous slip distributions were estimated from tsunami and geodetic data. We defined Sa for subfaults exhibiting slip greater than 1.5 times D. Adding 25 slip models of 10 great earthquakes around Japan, we recalculated regression relations for 32 slip models: S = 1.34 × 10 -10 M02/3, D = 1.66 × 10-7 M01/3, Sa = 2.81 × 10-11 M02/3, and Sa/S = 0.2, where S and S a are in square kilometers, M0 is in newton meters, and D is in meters. These scaling relations are very similar to those obtained by Murotani et al. (2008) for large and great earthquakes. Thus, both scaling relations can be used for future tsunami hazard assessment associated with a giant earthquake. Key Points The source scaling relations for M∼9 earthquakes are similar to those of M<8 Asperity area is 20% of source area on average regardless of earthquake size These relations can be used for tsunami modeling from giant earthquakes ©2013. American Geophysical Union. All Rights Reserved.