Presenter: Ming-Hsuan Yen
Date: 2016/01/07
Abstract
Scale invariance occurs in many natural phenomena, shows similar statistical characteristics at various scales. Several studies have been carried out to investigate the source scaling of earthquakes for understanding the self-similarity of earthquakes, and use source scaling to give deterministic parameters for ground-motion prediction. These two studies compiled finite fault slip models of the earthquakes in Taiwan orogenic belt and global earthquakes to determine the self-similarity of the slip distribution. First study observed two trends of scaling relationship respectively for the seismic moment smaller than and greater than 1020 Nm. The spatial slip distribution for large earthquakes (MW>7.0) tends to have a more homogeneous slip distribution compared to the moderate events. A breaking of the source scaling of asperity between MW>7.0 and MW<7.0 was found. The difference in scaling behavior might be attributed to the rupture dynamics. Several distinct events with the seismic moment less than 1019 Nm show very high stress drops, and yield local high PGA, as determined from comparison to the NGA model. These events, from buried faults in the fold-and-thrust belt of the orogenic zone, will require special attention because they had small fault dimensions but large slip. These studies provides important basis for ground-motion prediction, which is crucial for assessing seismic hazards, and simulating scenario earthquakes.
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