Details
| Original language | English |
|---|---|
| Article number | e2022GL101320 |
| Journal | Geophysical Research Letters |
| Volume | 50 |
| Issue number | 3 |
| Publication status | Published - 2 Feb 2023 |
Abstract
poorly understood. Here, we use numerical force-balance models combined with Coulomb failure analysis to show that the megathrust stress drop supports normal faulting, but that forearc-wide aftershock triggering is feasible within a narrow range of megathrust stress drop values and preseismic stress states only. We determine this range for the 2011 Tohoku earthquake (Japan) and show that the associated stress changes explain the aftershock seismicity in unprecedented detail and are consistent with the stress released by forearc seismicity before and after the earthquake.
Keywords
- aftershocks, force balance, megathrust earthquake, stress, stress drop, Tohoku earthquake
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- General Earth and Planetary Sciences
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In: Geophysical Research Letters, Vol. 50, No. 3, e2022GL101320, 02.02.2023.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Megathrust stress drop as trigger of aftershock seismicity
T2 - Insights from the 2011 Tohoku earthquake, Japan
AU - Dielforder, Armin
AU - Bocchini, Gian Maria
AU - Kemna, Kilian
AU - Hampel, Andrea
AU - Harrington, Rebecca
AU - Oncken, Onno
N1 - Funding Information: We thank S. Takemura (ERI, Japan) and D. Tian (MSU, USA) for the helpful suggestions on downloading and processing of Hi-net data from Japan. We thank the National Research Institute for Earth Science and Disaster Resilience and the Japan Meteorological Agency for granting open access to seismological data. Reviews by Iris van Zelst and an anonymous reviewer improved the clarity of the manuscript.
PY - 2023/2/2
Y1 - 2023/2/2
N2 - Numerous normal-faulting aftershocks in subduction forearcs commonly follow large megathrust earthquakes. Postseismic normal faulting has been explained by stress changes induced by the stress drop along the megathrust. However, details of forearc stress changes and aftershock triggering mechanisms remainpoorly understood. Here, we use numerical force-balance models combined with Coulomb failure analysis to show that the megathrust stress drop supports normal faulting, but that forearc-wide aftershock triggering is feasible within a narrow range of megathrust stress drop values and preseismic stress states only. We determine this range for the 2011 Tohoku earthquake (Japan) and show that the associated stress changes explain the aftershock seismicity in unprecedented detail and are consistent with the stress released by forearc seismicity before and after the earthquake.
AB - Numerous normal-faulting aftershocks in subduction forearcs commonly follow large megathrust earthquakes. Postseismic normal faulting has been explained by stress changes induced by the stress drop along the megathrust. However, details of forearc stress changes and aftershock triggering mechanisms remainpoorly understood. Here, we use numerical force-balance models combined with Coulomb failure analysis to show that the megathrust stress drop supports normal faulting, but that forearc-wide aftershock triggering is feasible within a narrow range of megathrust stress drop values and preseismic stress states only. We determine this range for the 2011 Tohoku earthquake (Japan) and show that the associated stress changes explain the aftershock seismicity in unprecedented detail and are consistent with the stress released by forearc seismicity before and after the earthquake.
KW - aftershocks
KW - force balance
KW - megathrust earthquake
KW - stress
KW - stress drop
KW - Tohoku earthquake
UR - http://www.scopus.com/inward/record.url?scp=85147909680&partnerID=8YFLogxK
U2 - 10.1029/2022GL101320
DO - 10.1029/2022GL101320
M3 - Article
VL - 50
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 3
M1 - e2022GL101320
ER -