2011年日本9级大地震的同震和震后滑移
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摘要
多数大地震都是沿大洋板块向大陆板块俯冲的海沟发生。现在已经清楚矩震级MW达到9级的巨大地震只发生在几个地区,包括智利、阿拉斯加、堪察加半岛和苏门答腊。日本海沟是太平洋板块向鄂霍次克海板块俯冲的地区,并没有历史记载表明这里曾发生过矩震级9级的大地震,唯一可能的例外是公元869年贞观(Jogan)大地震[1],其震级到现在为止还没有被很好地确定。然而,近来通过大地测量学观测估计得到的应变积累速率远远高出了先前板间地震所释放的平均应变速率[-26]。这一研究结果提出了一个问题,即类似区域如何释放累积的应变。2011年3月发生的MW9.0大型逆冲区地震(以下称东日本大地震)使日本东北部太平洋海岸附近海域的板块边界破裂。基于全球定位系统(GPS)网络探测的地面位移,本文给出了同震和震后滑移量的分布。同震滑移区沿日本海沟延伸了近400 km,这和震前闭锁区域吻合[4]。震后余滑与同震位移区在开始区段有部分重叠,并且扩展至周边地区。截至2011年3月25日,震后余滑区深度达近100 km,释放的能量相当于MW8.3。由于东日本大地震释放了数百年间累积的应变,所以应变积累失衡的矛盾可能得以部分解除。此次地震提醒我们沿其他海沟系统发生MW≈9地震的可能性——即使没有证据表明过去曾发生类似规模的事件。因此,利用空间大地测量手段监测应变积累以对地震危险性作出评估是非常必要的。
引文
[1]Minoura K,Imamura F,Sugawara D,et al.The 869 Jogan tsunami deposit and recurrence interval oflarge-scale tsunami on the Pacific coast of northeast Japan.J.Nat.Disaster Sci.,2001,23:83-88
[2]Peterson E T,Seno T.Factors affecting seismic moment release rates in subduction zones.J.Geophys.Res.,1984,89:10233-10248
[3]Pacheco J F,Sykes L R,Scholz C H.Nature of seismic coupling along simple plate boundaries of the sub-duction type.J.Geophys.Res.,1993,98:14133-14159
[4]Nishimura T,Hirasawa T,Miyazaki S,et al.Temporal change of interplate coupling in northeastern Ja-pan during 1995—2002 estimated from continuous GPS observations.Geophys.J.Int.,2004,157:901-
[5]Hashimoto C,Noda A,Sagiya T,et al.Interplate seismogenic zones along the Kuril-Japan trench fromGPS data inversion.Nature Geosci.,2009,2:141-144
[6]Suwa Y,Miura S,Hasegawa A,et al.Interplate coupling beneath NE Japan inferred from three-dimen-sional displacement field.J.Geophys.Res.,2006,111:B04402
[7]Sella G F,Dixon T H,Mao A.REVEL:a model for recent plate velocities from space geodesy.J.Geo-phys.Res.,2002,107:2081
[8]Apel E V,Burgmann R,Steblov G,et al.Independent active microplate tectonics of northeast Asia fromGPS velocities and block modeling.Geophys.Res.Lett.,2006,33:L11303
[9]Utsu T.Chronological table of earthquakes in Japan with a moment magnitude larger than6.0and disas-trous earthquakes from 1885 to 1980.Bull.Earthq.Res.Inst.,1983,57:401-463
[10]Bird P.An updated digital model of plate boundaries.Geochem.Geophys.Geosyst.,2003,4:1027
[11]Global CMT Web Page.Global Centroid Moment Tensor Project
[12]Savage J C.A dislocation model of strain accumulation and release at a subduction zone.J.Geophys.Res.,1983,88:4984-4996
[13]Nishimura T,Miura S,Tachibana K,et al.Distribution of seismic coupling on the subducting plateboundary in northeastern Japan inferred from GPS observations.Tectonophysics,2000,323:217-238
[14]Uchida N,Matsuzawa T,Nakajima J,et al.Subduction of a wedge-shaped Philippine Sea plate beneathKanto,central Japan,estimated from converted waves and small repeating earthquakes.J.Geophys.Res.,2010,115:B07309
[15]Heki K,Miyazaki S,Tsuji H.Silent fault slip following an interplate thrust earthquake at the JapanTrench.Nature,1997,386:595-597
[16]Sagiya T,Miyazaki S,Tada T.Continuous GPS array and present-day crustal deformation of Japan.Pure Appl.Geophys.,2000,157:2303-2322
[17]Yabuki T,Matsu’ura M.Geodetic data inversion using a Bayesian information criterion for spatial distr-ibution of fault slip.Geophys.J.Int.,1992,109:363-375
[18]Nakajima J,Hasegawa A.Anomalous low-velocity zone and linear alignment of seismicity along it in thesubducted Pacific slab beneath Kanto,Japan:reactivation of subducted fracture zone?Geophys.Res.Lett.,2006,33:L16309
[19]Igarashi T,Matsuzawa T,Umino N,et al.Spatial distribution of focal mechanisms for and intraplateearthquakes associated with the subducting Pacific plate beneath the northeastern Japan arc:a triple-planeddeep seismic zone.J.Geophys.Res.,2001,106:2177-2191
[20]Nakajima J,Matsuzawa T,Hasegawa A,et al.Seismic imaging of arc magma and fluids under the cen-tral part of northeast Japan.Tectonophysics,2001,341:1-17
[21]Shearer P,Burgmann R.Lessons learned from the2004Sumatra-Andaman megathrust rupture.Annu.Rev.Earth Planet.Sci.,2010,38:103-131
[22]Pollitz F.Gravitational viscoelastic postseismic relaxation on a layered spherical earth.J.Geophys.Res.,1997,102:17921-17941
[23]Ozawa S,Kaidzu M,Murakami M,et al.Coseismic and postseismic crustal deformation after the MW8Tokach-iOki earthquake in Japan.Earth Planets Space,2004,56:675-680
[24]Hsu Y,Simons M,Avouac J P,et al.Frictional afterslip following the2005Nias-Simeulue earthquake,Sumatra.Science,2006,312:1921-1926
[25]Moreno M,Rosenau M,Oncken O.2010Maule earthquake slip correlates with pre-seismic locking ofAndean subduction zone.Nature,2010,467:198-202
[26]Melbourn T I,Webb F H,Stock J M,et al.Rapid postseismic transients in subduction zones from con-tinuous GPS.J.Geophys.Res.,2002,107:2241
[27]Chlieh M,Avouac J P,Hjorleifsdottir V,et al.Coseismic slip and afterslip of the great MW9.15Suma-tra-Andaman earthquake of 2004.Bull.Seism.Soc.Am.,2007,97:S152-S173
[28]Kato T.Secular and earthquake-related vertical crustal movements in Japan as deduced from tidal records(1951—1981).Tectonophysics,1983,97:183-200
[29]Matsu’ura T,Furusawa A,Saomoto H.Long-term and short-term vertical velocity profiles across theforearc in the NE Japan subduction zone.Quat.Res.,2009,71:227-238
[30]Suito H,Freymueller J T.A viscoelastic and afterslip postseismic deformation model for the1964Alaskaearthquake.J.Geophys.Res.,2009,114:B11404
[2]Peterson E T,Seno T.Factors affecting seismic moment release rates in subduction zones.J.Geophys.Res.,1984,89:10233-10248
[3]Pacheco J F,Sykes L R,Scholz C H.Nature of seismic coupling along simple plate boundaries of the sub-duction type.J.Geophys.Res.,1993,98:14133-14159
[4]Nishimura T,Hirasawa T,Miyazaki S,et al.Temporal change of interplate coupling in northeastern Ja-pan during 1995—2002 estimated from continuous GPS observations.Geophys.J.Int.,2004,157:901-
[5]Hashimoto C,Noda A,Sagiya T,et al.Interplate seismogenic zones along the Kuril-Japan trench fromGPS data inversion.Nature Geosci.,2009,2:141-144
[6]Suwa Y,Miura S,Hasegawa A,et al.Interplate coupling beneath NE Japan inferred from three-dimen-sional displacement field.J.Geophys.Res.,2006,111:B04402
[7]Sella G F,Dixon T H,Mao A.REVEL:a model for recent plate velocities from space geodesy.J.Geo-phys.Res.,2002,107:2081
[8]Apel E V,Burgmann R,Steblov G,et al.Independent active microplate tectonics of northeast Asia fromGPS velocities and block modeling.Geophys.Res.Lett.,2006,33:L11303
[9]Utsu T.Chronological table of earthquakes in Japan with a moment magnitude larger than6.0and disas-trous earthquakes from 1885 to 1980.Bull.Earthq.Res.Inst.,1983,57:401-463
[10]Bird P.An updated digital model of plate boundaries.Geochem.Geophys.Geosyst.,2003,4:1027
[11]Global CMT Web Page.Global Centroid Moment Tensor Project
[12]Savage J C.A dislocation model of strain accumulation and release at a subduction zone.J.Geophys.Res.,1983,88:4984-4996
[13]Nishimura T,Miura S,Tachibana K,et al.Distribution of seismic coupling on the subducting plateboundary in northeastern Japan inferred from GPS observations.Tectonophysics,2000,323:217-238
[14]Uchida N,Matsuzawa T,Nakajima J,et al.Subduction of a wedge-shaped Philippine Sea plate beneathKanto,central Japan,estimated from converted waves and small repeating earthquakes.J.Geophys.Res.,2010,115:B07309
[15]Heki K,Miyazaki S,Tsuji H.Silent fault slip following an interplate thrust earthquake at the JapanTrench.Nature,1997,386:595-597
[16]Sagiya T,Miyazaki S,Tada T.Continuous GPS array and present-day crustal deformation of Japan.Pure Appl.Geophys.,2000,157:2303-2322
[17]Yabuki T,Matsu’ura M.Geodetic data inversion using a Bayesian information criterion for spatial distr-ibution of fault slip.Geophys.J.Int.,1992,109:363-375
[18]Nakajima J,Hasegawa A.Anomalous low-velocity zone and linear alignment of seismicity along it in thesubducted Pacific slab beneath Kanto,Japan:reactivation of subducted fracture zone?Geophys.Res.Lett.,2006,33:L16309
[19]Igarashi T,Matsuzawa T,Umino N,et al.Spatial distribution of focal mechanisms for and intraplateearthquakes associated with the subducting Pacific plate beneath the northeastern Japan arc:a triple-planeddeep seismic zone.J.Geophys.Res.,2001,106:2177-2191
[20]Nakajima J,Matsuzawa T,Hasegawa A,et al.Seismic imaging of arc magma and fluids under the cen-tral part of northeast Japan.Tectonophysics,2001,341:1-17
[21]Shearer P,Burgmann R.Lessons learned from the2004Sumatra-Andaman megathrust rupture.Annu.Rev.Earth Planet.Sci.,2010,38:103-131
[22]Pollitz F.Gravitational viscoelastic postseismic relaxation on a layered spherical earth.J.Geophys.Res.,1997,102:17921-17941
[23]Ozawa S,Kaidzu M,Murakami M,et al.Coseismic and postseismic crustal deformation after the MW8Tokach-iOki earthquake in Japan.Earth Planets Space,2004,56:675-680
[24]Hsu Y,Simons M,Avouac J P,et al.Frictional afterslip following the2005Nias-Simeulue earthquake,Sumatra.Science,2006,312:1921-1926
[25]Moreno M,Rosenau M,Oncken O.2010Maule earthquake slip correlates with pre-seismic locking ofAndean subduction zone.Nature,2010,467:198-202
[26]Melbourn T I,Webb F H,Stock J M,et al.Rapid postseismic transients in subduction zones from con-tinuous GPS.J.Geophys.Res.,2002,107:2241
[27]Chlieh M,Avouac J P,Hjorleifsdottir V,et al.Coseismic slip and afterslip of the great MW9.15Suma-tra-Andaman earthquake of 2004.Bull.Seism.Soc.Am.,2007,97:S152-S173
[28]Kato T.Secular and earthquake-related vertical crustal movements in Japan as deduced from tidal records(1951—1981).Tectonophysics,1983,97:183-200
[29]Matsu’ura T,Furusawa A,Saomoto H.Long-term and short-term vertical velocity profiles across theforearc in the NE Japan subduction zone.Quat.Res.,2009,71:227-238
[30]Suito H,Freymueller J T.A viscoelastic and afterslip postseismic deformation model for the1964Alaskaearthquake.J.Geophys.Res.,2009,114:B11404
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