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A Global Set of Subduction Zone Earthquake Scenarios Inferred From Geodetically Constrained Block Models

Session: Constructing and Testing Regional and Global Earthquake Forecasts I

Type: Oral

Date: 4/20/2021

Presentation Time: 10:15 AM Pacific

Description: 

The past 100 years have seen the occurrence of 5 M_W>9 earthquakes and 94 M_W>8 earthquakes. Here we assess the potential for future great earthquakes using inferences of interseismic subduction zone coupling from a global block model incorporating both tectonic plate motions and earthquake cycle effects. Interseismic earthquake cycle effects are represented using a first-order quasistatic elastic approximation and include ~10⁷ km² of interacting fault system area across the global fault system. We use spatial variations in decadal-duration coupling at 15 subduction zones and the Himalayan range front to estimate the potential locations and magnitude of future seismic events using empirical scaling relationships relating rupture area to moment magnitude. At an interseismic coupling threshold of 30%, we estimate 14 potential M_W>9 earthquakes globally. At higher coupling thresholds, estimates of potential earthquake magnitudes decrease, but the total number of large earthquakes varies non-monotonically. We also combine slip deficit rate and potential event magnitudes to estimate earthquake recurrence intervals for large earthquake scenarios.

Presenting Author: Brendan J. Meade

Student Presenter: No

Authors