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Regionalized Earthquake Source Models of Subduction Interface Earthquakes

Description: 

In Skarlatoudis et al. (2016; Sea16), we established global scaling relations between seismic moment (M₀) and physical source properties such as earthquake rupture area (S), total asperity area (S_a), slip (D), and fault width (W) for large subduction interface events. These relations significantly reduced the variability in predicting these source parameters. Since their publication, researchers and institutions worldwide have utilized these scaling relations to forecast ground motions and tsunamis from significant subduction earthquakes for various applications, including the US National Seismic Hazard Maps.
Since the creation of the Sea16 database, and by using the Slab2.0 (Hayes, 2018) subduction zone geometries, we identified 79 additional subduction interface events with published finite fault solutions that have been catalogued in the USGS Finite Fault database, the Online Database of Finite Fault Rupture Models (SRCMOD; Mai and Thingbaijam, 2014), and the Next Generation Attenuation Subduction (NGA-Sub) database, nearly tripling the available data. We expanded our existing database of subduction interface events with these additional models and developed an updated set of global scaling relations enhancing predictions of various source properties and reducing uncertainties.
The differences between the regression coefficients from this study and Sea16 were generally small. However, we showed that rupture length has a linear scaling relationship with seismic moment, but rupture width saturates, causing a decrease in scaling of rupture area, which is offset by an increase in slip. This is analogous to the saturation of rupture width, identified in shallow crustal earthquakes. Furthermore, for subduction zones with an adequate number of earthquakes in our database, we examined regionalized versions of the scaling relations and explored possible explanations for the observed regional differences in subduction interface ground motions by seeking correlations with various parameters such as trench-normal trench velocity, thrust dip angle and subduction partitioning.

Session: Advances in Reliable Earthquake Source Parameter Estimation [Poster]

Type: Poster

Date: 4/16/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Andreas

Student Presenter: No

Invited Presentation: 

Poster Number: 35

Authors