TITLE:
Stress rise precursor to earthquakes in the Tibetan Plateau
AUTHORS:
Zhenhan Wu, Qunce Chen, Patrick J. Barosh, Hua Peng, Daogong Hu
KEYWORDS:
Earthquake Prediction; High Stress Anomalies; In-Situ Stress Measurement; Large Earthquakes; Seismic Fault; Tibetan Plateau
JOURNAL NAME:
Natural Science,
Vol.5 No.8A,
August
20,
2013
ABSTRACT: Earthquake prediction
thus far has proven to be a very difficult task, but changes in situ stress appear
to offer a viable approach for forecasting large earthquakes in Tibet and
perhaps other continental regions. High
stress anomalies formed along active faults before large earthquakes and
disappeared soon after the earthquakes occurred in the Tibetan Plateau. Principle
stress increased up to ~2 -5 times higher than background stress to form high
stress anomalies along causative faults before the Ms 8.1 West Kunlun Pass earthquake
in November 2001, Ms 8.0 Wenchuan earthquake in May 2008, Ms 6.6 Nimu
earthquake in October 2009, Ms 7.1 Yushu earthquake in April 2010 and the Ms
7.0 Lushan earthquake in April 2013. Stress near the epicenters rapidly
increased 0.10 - 0.12 MPa over 45 days, ~8 months before the Ms 6.6 Nimu earthquake
occurred. The high principle stress anomalies decreased quickly to the normal
stress state in ~8 -12 months after the Ms 8.1 West Kunlun Pass and the Ms 8.0
Wenchuan earthquakes. These high stress anomalies and their demise appear
directly related to the immediate stress rise along a fault prior to the earthquakes
and the release during the event. Thus, the stress rise appears to be a viable
precursor in prediction of large continental earthquakes as in the Tibetan
Plateau.