摘要
WeusedearthquakecatalogsrecordedbyGuangdongSeismologicalNetworkfrom2008to2014toresolvethespatialvariationsofb-valuesinthecoastalareaofGuangdong,particularlyinthreekeyresearchareas(Yangjiang,Heyuan,andoffshoreNanaoIsland)withstrongseismicity.Ourresultsrevealedthatb-valuesexhibitedsignificantspatialvariations,andzoneswithlowb-valuescouldindicatethemostlikelyseismogenicareaoflargeearthquakes.Weobservedthreeclearlowb-valuepatchesintheoffshoreNanaoIsland.Wefoundadistincthighb-valuepeakatthedepthof11kmandtwominimumpeaksatabout14and7–8kmintheYangjiangarea.Theoverallb-valuesgenerallydecreasewithdepthintheHeyuanarea.Thespatialvariationsofb-valuesreflecttectonicanomalies;thatis,the‘low-high-low’distributionofb-valuesintheoffshoreNanaoIslandandtheYangjiangareamayindicatetheanomalyofthecrustalstructurewithaweaklayer.Theb-valuesofreservoir-inducedseismicityareobviouslylowerthanthatinducedbytectonism.Thisfindingindicatesthatthereservoirareaisgenerallyathighstressstateundertheconditionofhighporepressure.Weinferredthatlargeearthquakesmightbepronetooccurat10–12kmdepthintheoffshoreNanaoIsland,at12–15kmdepthintheYangjiangarea,andatthelowerpartoftheseismicactivityzoneintheHeyuanarea.Moreover,theupstreamareaoftheXinfengjiangreservoiristhemostlikelyareaoffuturelargeearthquakesintheHeyuanarea.
出版日期
2018年01月11日(中国期刊网平台首次上网日期,不代表论文的发表时间)