Earthquake Nucleation and Global Induced Stress Field by Precedent Large Earthquakes Since 1900

Session: Crustal Stress and Strain and Implications for Fault Interaction and Slip
Type: Oral
Date: 4/28/2020
Time: 08:30 AM
Room: 240
Description: 

The earthquake occurrence is controlled by the stress field that is fractionally modulated by local and regional effects. The influence of fractional stress changes by precedent earthquakes on the induction of forthcoming earthquakes is investigated. We assess the global stress perturbation induced by 1626 earthquakes with magnitudes greater than or equal to 7.0 since 1900. We stack the Coulomb stress changes. The cumulative Coulomb stress changes reach up to an order of tens to hundreds of bars at convergent plate boundaries. Great earthquakes dominantly controlled the stress perturbation. Descendant large earthquakes appeared to occur in the regions with large lateral gradients in cumulative Coulomb stress changes induced by precedent earthquakes. The cumulative Coulomb stress changes over a century are comparable among subduction zones. The seismicity in subduction zones may depend on the strength of the stress field as well as the lateral gradient in the stress field. The instability and inhomogeneity in stress field may play an important role in nucleation of great earthquakes.

Presenting Author: Tae-Kyung Hong

Authors