Characteristics of strain release before moderate-strong earthquakes in Yunnan region
Qian Xiaodong
Li Qiong
Hong Min
Abstract：Referring to the earthquake catalogues produced by the Yunnan Re-gional Seismic Network,and setting the seismic strain energy as a scale of the seismic energy release,this paper conducts a nonlinear simulation for the pre-cursory earthquake-sequences based on the accelerating strain release model.In the period from 1966 to 2013,115 earthquakes with MS ≥5.0 occurred in Yun-nan region.Among them,79 events are characterized by accelerating strain re-lease,accounting for 69%.And 28 events are featured as decelerating strain re-lease,accounting for 24%.The strain releases of the rest eight events account-ing for 7% fail to show the features of acceleration or deceleration due to the less seismic data.As to the precursory earthquake sequences whose main shocks belong to the single-shock type,the ones whose earthquake strain releases are accelerating,or the ones lacking seismic data,are far more than the ones whose strain releases are accelerating.As to the precursory earthquake sequences whose main shocks belong to the strike-slip type,the ones whose earthquake strain releases are accelerating are 15% more than the ones whose main shocks belong to the normal-fault type,or 15% more than the thrust-fault type ones. The searching radius has an inverse relation with the duration of the precursory earthquake sequence.The simulated results for the precursory earthquake-sequences indicate that the error of the main shock’s magnitude is ±0.30,and the error of the main shock’s occurrence time is ±0.5 year.
Keywords：accelerating strain releasepower exponentmid-short term predic-tionYunnan region
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 386-401 )