Coulomb pre-stress and fault bends are ignored yet vital factors for earthquake triggering and hazard.

ABSTRACT: Successive locations of individual large earthquakes (M_w > 5.5) over years to centuries can be difficult to explain with simple Coulomb stress transfer (CST) because it is common for seismicity to circumvent nearest-neighbour along-strike faults where coseismic CST is greatest. We demonstrate that Coulomb pre-stress (the cumulative CST from multiple earthquakes and interseismic loading on non-planar faults) may explain this, evidenced by study of a 667-year historical record of earthquakes in central Italy. Heterogeneity in Coulomb pre-stresses across the fault system is >±50 bars, whereas coseismic CST is <±2 bars, so the latter will rarely overwhelm the former, explaining why historical earthquakes rarely rupture nearest neighbor faults. However, earthquakes do tend to occur w

SUBMITTER: Mildon ZK 

PROVIDER: S-EPMC6588554 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature