Abstract

Successive locations of individual large earthquakes (Mw > 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 where the cumulative coseismic and interseismic CST is positive, although there are notable examples where earthquake propagate across negatively stressed portions of faults. Hence Coulomb pre-stress calculated for non-planar faults is an ignored yet vital factor for earthquake triggering.

Details

Title
Coulomb pre-stress and fault bends are ignored yet vital factors for earthquake triggering and hazard
Author
Mildon, Z K 1   VIAFID ORCID Logo  ; Roberts, G P 2 ; Faure Walker, J P 3   VIAFID ORCID Logo  ; Toda, S 4 

1  School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, UK; Institute for Risk and Disaster Reduction, University College London, London, UK 
2  Department of Earth and Planetary Sciences, Birkbeck, University of London, London, UK 
3  Institute for Risk and Disaster Reduction, University College London, London, UK 
4  International Research Institute of Disaster Science, Tohoku University, Aoba-ku, Sendai, Japan 
Pages
1-9
Publication year
2019
Publication date
Jun 2019
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-019-10520-6
ProQuest document ID
2244646990
Copyright
© 2019. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.