Abstract
In 2001 three earthquakes occurred in Shidian in Yunnan Province, which were the M S=5.2 on April 10, the M S=5.9 on April 12 and the M S=5.3 on June 8. Based on the data from the station Baoshan of Yunnan Telemetry Digital Seismograph Network, the variational characteristics of shear-wave splitting on these series of strong earthquakes has been studied by using the systematic analysis method (SAM) of shear-wave splitting. The result shows the time delays of shear-wave splitting basically increase with earthquake activity intensifying. However the time delays abruptly decrease immediately before strong aftershocks. It accords with the stress relaxation before earthquakes, which was found recently in study on shear-wave splitting. The result suggests it is significant for reducing the harm degree of earthquakes to develop the stress-forecasting on earthquake in strong active tectonic zones and economic developed regions or big cities under the danger of strong earthquakes.
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References
CHEN Tian-chang. 1994. The time variation of shear wave polarization after earthquake [A]. In: CHEN Yun-tai, KAN Rong-ju, TENG Ji-wen, et al eds. Advances in Solid Earth Geophysics in China [C]. Beijing: Oceanic Press, 352–357 (in Chinese).
Crampin S. 1978. Seismic-wave propagation through a cracked solid: Polarization as a possible dilatancy diagnostic [J]. Geophys J R astr Soc, 53: 467–496.
Crampin S. 1999. Calculable fluid-rock interactions [J]. J Geol Soc, 156: 501–514.
Crampin S. 2001. Developing stress-monitoring sites using cross-hole seismology to stress-forecast the times and magnitudes of future earthquakes [J]. Tectonophysics, 338: 233–245.
Crampin S, Gao Y, Chastin S, et al. 2003. Speculations on earthquake forecasting [J]. Seism Res Lett, 74(3): 271–273.
Crampin S, Volti T, Stefánsson R. 1999. A successfully stress-forecast earthquake [J]. Geophys J Int, 138: F1-F5.
Gao Y, Crampin S. 2003. Temporal variations of shear-wave splitting in field and laboratory in China [J]. J Appl Geophys, 54: 279–287.
Gao Y, Crampin S. 2004. Observations of stress relaxation before earthquakes [J]. Geophys J Int, 157(2): 578–582.
Gao Y, Wang P D, Zheng S H, et al. 1998. Temporal changes in shear-wave splitting at an isolated swarm of small earthquakes in 1992 near Dongfang, Hainan Island, southern China [J]. Geophys J Int, 135(1): 102–112.
GAO Yuan, ZHENG Si-hua. 1994. On shear-wave splitting in Tangshan region (II) — Correlation function analysis method [J]. Earthquake Research in China, 10(Suppl.): 11–21 (in Chinese).
GAO Yuan, ZHENG Si-hua, SUN Yong. 1995. Crack-induced anisotropy in the crust from shear wave splitting observed in Tangshan region, North China [J]. Acta Seismologica Sinica, 8(3): 351–363.
GAO Yuan, ZHENG Si-hua, WANG Pei-de. 1996. Shear wave splitting study on small earthquake swarm of 1992 in Dongfang of Hainan, South China [J]. Chinese J Geophys, 39(2): 221–232 (in Chinese).
GAO Yuan, ZHENG Si-hua, ZHOU Hui-lan. 1999. Polarization patterns of fast shear wave in Tangshan region and their variations [J]. Chinese J Geophys, 42(2): 228–232 (in Chinese).
LEI Jun, WANG Pei-de, YAO Chen, et al. 1997. The near-field shear wave splitting and its relation with structure in Jianchuan, Yunnan Province [J]. Chinese J Geophys, 40(6): 791–801 (in Chinese).
LI Bai-ji. 1996. Change of splitting S-wave of aftershocks of Luquan earthquake in Yunnan [J]. Acta Seismologica Sinica, 9(2): 289–297.
SU You-jin, QIN Jia-zheng. 2001. Strong earthquake activity and relation to regional neotectonic movement in Sichuan-Yunnan region [J]. Earthquake Research in China, 17(1): 24–34 (in Chinese).
SUN Yong, ZHENG Si-hua. 1993. On shear-wave splitting in Tangshan region [J]. Earthq Research in China, 9(1): 60–67 (in Chinese).
Volti T, Crampin S. 2003. A four-year study of shear-wave splitting in Iceland: 1-Background and preliminary analysis [A]. In: Nieuwland D A ed. New Insights Into Structural Interpretation and Modelling, Geological Society, Special Publication 212 [C]. London: Geological Society, 117–133.
XU Xi-wei, HE Chang-rong. 1996. Formation of new generated faults and foreshock activity [A]. In: Editorial Board of Studies on Active Faults eds. Studies on Active Faults 5 [C]. Beijing: Seismological Press, 197–210 (in Chinese).
YAO Chen, WANG Pei-de, CHEN Yun-tai. 1992. Shear-wave polarization and crack induced anisotropy of upper crust in Lulong, North China [J]. Chinese J Geophys, 35(3): 305–315 (in Chinese).
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Foundation item: National Natural Science Foundation of China (40274011, 40074020), MOST (2001BA601B02) and Joint Seismological Science Foundation of China (102068).
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Gao, Y., Liang, W., Ding, X. et al. Variational characteristics of shear-wave splitting on the 2001 Shidian earthquakes in Yunnan, China. Acta Seimol. Sin. 17, 635–641 (2004). https://doi.org/10.1007/s11589-004-0002-8
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DOI: https://doi.org/10.1007/s11589-004-0002-8