Evidence from the AD 2000 Izu islands earthquake swarm that stressing rate governs seismicity

被引:332
作者
Toda, S [1 ]
Stein, RS
Sagiya, T
机构
[1] AIST, Act Fault Res Ctr, Geol Survey Japan, Tsukuba, Ibaraki 3058567, Japan
[2] US Geol Survey, Menlo Pk, CA 94025 USA
[3] Geol Survey Inst, Tsukuba, Ibaraki 3050811, Japan
基金
美国国家科学基金会;
关键词
D O I
10.1038/nature00997
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Magma intrusions and eruptions commonly produce abrupt changes in seismicity far from magma conduits(1-4) that cannot be associated with the diffusion of pore fluids or heat(5). Such 'swarm' seismicity also migrates with time, and often exhibits a 'dog-bone'-shaped distribution(3,4,6-9). The largest earthquakes in swarms produce aftershocks that obey an Omori-type (exponential) temporal decay(10-12), but the duration of the aftershock sequences is drastically reduced, relative to normal earthquake activity(7,13). Here we use one of the most energetic swarms ever recorded to study the dependence of these properties on the stress imparted by a magma intrusion(8,11,14,15). A 1,000-fold increase in seismicity rate and a 1,000-fold decrease in aftershock duration occurred during the two-month-long dyke intrusion. We find that the seismicity rate is proportional to the calculated stressing rate, and that the duration of aftershock sequences is inversely proportional to the stressing rate. This behaviour is in accord with a laboratory-based rate/state constitutive law 16, suggesting an explanation for the occurrence of earthquake swarms. Any sustained increase in stressing rate-whether due to an intrusion, extrusion or creep event-should produce such seismological behaviour.
引用
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页码:58 / 61
页数:4
相关论文
共 22 条
[1]   Imaging magma transport during the 1997 seismic swarm off the Izu Peninsula, Japan [J].
Aoki, Y ;
Segall, P ;
Kato, T ;
Cervelli, P ;
Shimada, S .
SCIENCE, 1999, 286 (5441) :927-930
[2]   CURRENT RIFTING EPISODE IN NORTH ICELAND [J].
BJORNSSON, A ;
SAEMUNDSSON, K ;
EINARSSON, P ;
TRYGGVASON, E ;
GRONVOLD, K .
NATURE, 1977, 266 (5600) :318-323
[3]   Long-period volcano seismicity: Its source and use in eruption forecasting [J].
Chouet, BA .
NATURE, 1996, 380 (6572) :309-316
[4]   RAPID INTRUSION OF MAGMA INTO WET ROCK - GROUNDWATER-FLOW DUE TO PORE PRESSURE INCREASES [J].
DELANEY, PT .
JOURNAL OF GEOPHYSICAL RESEARCH, 1982, 87 (NB9) :7739-7756
[5]   The use of earthquake rate changes as a stress meter at Kilauea volcano [J].
Dieterich, J ;
Cayol, V ;
Okubo, P .
NATURE, 2000, 408 (6811) :457-460
[7]   MECHANICAL RESPONSE OF THE SOUTH FLANK OF KILAUEA VOLCANO, HAWAII, TO INTRUSIVE EVENTS ALONG THE RIFT SYSTEMS [J].
DVORAK, JJ ;
OKAMURA, AT ;
ENGLISH, TT ;
KOYANAGI, RY ;
NAKATA, JS ;
SAKO, MK ;
TANIGAWA, WT ;
YAMASHITA, KM .
TECTONOPHYSICS, 1986, 124 (3-4) :193-209
[8]  
GROSS SJ, 1994, B SEISMOL SOC AM, V84, P1571
[9]   MODEL FOR EARTHQUAKE SWARMS [J].
HILL, DP .
JOURNAL OF GEOPHYSICAL RESEARCH, 1977, 82 (08) :1347-1352
[10]  
INGEBRITSEN SE, 1998, GROUNDWATER GEOLOGIC, P16