Magnitude-dependent transient deepening of brittle-ductile transition zone along strike-slip fault

Olaf Zielke, D. Schorlemmer, Sigurjon Jonsson, Paul Martin Mai

    Research output: Contribution to journalArticlepeer-review

    Abstract

    The thickness of the seismogenic zone in the Earth’s crust plays an important role in seismo tectonics, affecting fault system architecture and relative fault activity, earthquake size and distribution within a fault system, and long-term accumulation of tectonic deformation. Within the last two decades, several studies have revealed that aftershocks of large continental earthquakes may occur below the background depth of the seismogenic zone, i.e., below the seismic-aseismic transition zone. This observation may be explained with a strain- and strain-rate induced shift in rheological behavior that follows large mainshocks, transiently changing the deformation style below the seismogenic zone from incipient ductile to seismically brittle failure. As large earthquakes transiently deepen the seismic-aseismic transition zone, it is plausible to assume that larger mainshocks may cause stronger deepening than smaller mainshocks. Corresponding observations however have not yet been reported. Here, we use well-located seismic catalogs from Alaska, California, Japan, and Turkey to analyze if mainshock size positively correlates with the amount of transient deepening of the seismic-aseismic tranition zone. We compare the depths of background seismicity with aftershock depths of 16 continental strike-slip earthquakes (6
    Original languageEnglish (US)
    JournalGeophys. Res. Lett.
    StatePublished - Jan 15 2020

    Fingerprint Dive into the research topics of 'Magnitude-dependent transient deepening of brittle-ductile transition zone along strike-slip fault'. Together they form a unique fingerprint.

    Cite this