Long-term induced seismicity on the Mosha fault by the Damavand Volcano, N-Iran, Implications for the seismic hazard of the Tehran metropolis
Abstract
Seismic history of the Mosha fault, the most important active fault of Eastern Tehran metropolis, and its relation to the activity of Damavand Volcano, the highest mountain of the Middle-East, is investigated. Historical earthquakes cover the three segments of the Mosha fault by three 6.5<M<7.7 events. Instrumental earthquake catalogs show that the seismicity of the central segment of Mosha fault, close to the Damavand Volcano, is quite high compared to its Western and eastern segments. On May 7th, 2020, an Mw5.1 earthquake struck 40 km East of Tehran, on the central segment of the Mosha fault, 10 Km South of Damavand Volcano crest. Its moment tensor obtained by inverting the local broadband displacement waveforms, showed a strike-slip mechanism with N-S and WNW-ESE planes and a centroid depth in 12 km. Its extended rupture was imaged on a single elliptical slip patch that nucleates at a depth of 14 km; we find that slip grows mostly toward up-dip and to the WNW with an average speed of ~2.5 km/s and lasts for ~2.8 s, releasing a total scalar seismic moment of ~4.8E+16 Nm. Early aftershocks (first 45 days), were mainly distributed in the up-dip direction of the slip model, showing a strong directivity effect of the mainshock.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMS016...03M
- Keywords:
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- 7209 Earthquake dynamics;
- SEISMOLOGY;
- 7223 Earthquake interaction;
- forecasting;
- and prediction;
- SEISMOLOGY;
- 7230 Seismicity and tectonics;
- SEISMOLOGY;
- 8168 Stresses: general;
- TECTONOPHYSICS