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Damage in step‐overs may enable large cascading earthquakes
Author(s) -
Finzi Y.,
Langer S.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052436
Subject(s) - seismology , geology , classification of discontinuities , earthquake rupture , seismic hazard , earthquake prediction , seismic gap , fault (geology) , rigidity (electromagnetism) , hazard analysis , hazard , foreshock , aftershock , structural engineering , engineering , reliability engineering , mathematical analysis , chemistry , mathematics , organic chemistry
Seismic hazard analysis relies on the ability to predict whether an earthquake will terminate at a fault tip or propagate onto adjacent faults, cascading into a larger, more devastating event. While ruptures are expected to arrest at fault discontinuities larger than 4–5 km, scientists are often puzzled by much larger rupture jumps. Here we show that material properties between faults significantly affect the ability to arrest propagating ruptures. Earthquake simulations accounting for fault step‐over zones weakened by accumulated damage provide new insights into rupture propagation. Revealing that lowered rigidity and material interfaces promote rupture propagation, our models show for the first time that step‐overs as wide as 10 km may not constitute effective earthquake barriers. Our results call for re‐evaluation of seismic hazard analyses that predict rupture length and earthquake magnitude based on historic records and fault segmentation models.