Earthquake Energy, Earthquake Volume, Aftershock Area, and Strength of the Earth's Crust

Tsuboi, Chûji

doi:10.4294/jpe1952.4.63

Cited by 142 publications

(28 citation statements)

References 2 publications

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“…However, our extensive resolution tests show that such a temporal variation of the low-V anomaly under the Wen-An source area can hardly be detected reliably by using the sparse ray path coverage in our present data sets which contain errors in both the hypocenter locations and arrival times. Tsuboi (1956) proposed a concept of earthquake volume, that is, the rupture nucleation zone should not be only limited within a 2-D volume but may have a 3-D spatial extent. According to the scaling law of Kanamori and Anderson (1975), if the spatial extent of the source zone of a M = 6-8 earthquake varies from about 10 km to over 100 km (Zhao et al, 2002), then that of the source Fig.…”

Section: Discussionmentioning

confidence: 99%

An attempt to detect temporal variations of crustal structure in the source area of the 2006 Wen-An earthquake in North China

Lei

Zhao

Xie

et al. 2011

Journal of Asian Earth Sciences

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Section: Discussionmentioning

confidence: 99%

An attempt to detect temporal variations of crustal structure in the source area of the 2006 Wen-An earthquake in North China

Lei

Zhao

Xie

et al. 2011

Journal of Asian Earth Sciences

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“…The second way in which the maximum magnitude may be estimated is from the maximum fault area for the faults within the zone and empirical relations between fault areas and magnitude or moment (Utsu & Seki 1954;Tsuboi 1956;Bath & Duda 1964;Press 1967as in Thatcher & Hanks 1973Kanamori & Anderson 1975;Burr & Solomon 1978;Acharya 1979 Sovanco and Nootka transform faults and slightly less for the Dellwood area faults. A fault width of 4 k m and 1:ngth of about 300 km gives a maximum magnitude of about 7.1 for the longer Blanco, Mendocino and Gulf of California transform faults.…”

Section: -0mentioning

confidence: 99%

Seismicity and rates of relative motion on the plate boundaries of Western North America

Hyndman¹,

Weichert²

1983

Geophysical Journal International

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The consistency of earthquake data and plate tectonic models and other estimates of fault slip, may be tested by estimating rates of motion from the earthquakes using the concept of seismic moment. The contribution of individual events may simply be summed, but a generally better estimate of long-term average slip rate is obtained by integration over magnitudefrequency of occurrence relations. Estimates of fault motion rates associated with earthquakes are possible within about a factor of 2 using this approach if the major sources of uncertainty are given careful consideration; e.g. incompleteness and inaccuracies in the earthquake data; empirical moment-magnitude relations and the effect of their stochasticity; fault 'widths' or depth extents; the recurrence relations; maximum magnitudes and the form of truncation at the maximum magnitude. A formulation for the recommended magnitude density truncation is developed. Application of the latter method to the earthquake data of the offshore transform faults of the Juan de Fuca ridge system, the Queen Charlotte fault zone and the northern Vancouver Island area in each case gives good agreement with rates from plate tectonic models. For the southern San Andreas fault and Gulf of California area there is also good agreement with previous estimates obtained by summing the contributions of individual events. However, the displacement rate in the margin convergence zone of southern British Columbia, Washington and Oregon computed from the seismicity is at least a factor of 10 lower than from plate models and from other convergence estimates, and primarily aseismic slip is suggested. The fault motions as a function of time computed from the seismicity records have also been plotted and compared to the longterm average rates. The plots permit estimates of the minimum present accumulated elastic strain, and show if there are any temporal relations among earthquake displacements on different fault zones. htroduc tionA basic understanding of the origin and nature of earthquakes in a region and detailed evaluation of the associated seismic risk requires development of valid tectonic models. Tectonic

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“…The rupture nucleation zone should have a three-dimensional spatial extent, not just limited to the two-dimensional surface of a fault, as suggested earlier by Tsuboi [32] in the concept of earthquake volume. Complex physical and chemical reactions will take place in the source zone of a future earthquake, causing heterogeneities in the material property and stress field, which can be detected with seismic tomography and other geophysical methods.…”

Section: Discussionmentioning

confidence: 88%

Fine three-dimensional P-wave velocity structure beneath the capital region and deep environment for the nucleation of strong earthquakes

HUANGJinli¹,

ZHAODapeng²

2005

Chinese Sci Bull

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A detailed 3-D P-wave velocity model of the crust and uppermost mantle under the capital region is determined with a spatial resolution of 25 km in the horizontal direction and 4-17 km in depth. We used 48750 precise P-wave arrival time data from 2973 events of local crustal earthquakes, controlled seismic explosions and quarry blasts. These events were recorded by 123 seismic stations. The data are analyzed by using a 3-D seismic tomography method. Our tomographic model provides new information on the geological structure and complex seismotectonics of this region. Different patterns of velocity structures show up in the North China Basin, the Taihangshan and the Yanshan Mountainous areas. The velocity images of the upper crust reflect well the surface geological, topographic and lithological features. In the North China Basin, the depression and uplift areas are imaged as slow and fast velocity belts, respectively, which are oriented in NE-SW direction. The trend of velocity anomalies is the same as that of major structure and tectonics. Paleozoic strata and Pre-Cambrian basement rocks outcrop widely in the Taihangshan and Yanshan uplift areas, which exhibit strong and broad high-velocity anomalies in our tomographic images, while the Quaternary intermountain basins show up as small low-velocity anomalies. Most of large earthquakes, such as the 1976 Tangshan earthquake (M 7.8) and the 1679 Sanhe earthquake (M 8.0), generally occurred in high-velocity areas in the upper to middle crust. However, in the lower crust to the uppermost mantle under the source zones of the large earthquakes, low-velocity and high-conductivity anomalies exist, which are considered to be associated with fluids, just like the 1995 Kobe earthquake (M 7.2) and the 2001 Indian Bhuj earthquake (M 7.8). The fluids in the lower crust may cause the weakening of the seismogenic layer in the upper and middle crust and thus contribute to the initiation of the large crustal earthquakes.North China is a platform with old tectonic basement, but it is a very active region from a seismotectonic point of view. The present study region is the northern portion of North China, which is located in the intersection of the Yanshan and the Taihangshan uplift regions (Fig. 1). Generally speaking, seismicity is less active in old platforms of the world. However, many strong earthquakes with magnitudes greater than M 7.0 have occurred in this region. Among them, the 1966 Xingtai earthquake (M 7.2) and the 1976 Tangshan earthquake (M 7.8) caused tremendous casualty and losses. Why do so strong earthquakes occur in this old platform? What are the tectonic backgrounds in the epicentral areas of these strong earthquakes? These questions have drawn broad attention. Some researchers have investigated the 3-D seismic velocity structure of the crust and upper mantle under this region using arrival times recorded by the previous seismic network [2][3][4][5][6] , and some deep seismic soundings (DSS) were also conducted to investigate the crustal structure in this region [...

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Earthquake Energy, Earthquake Volume, Aftershock Area, and Strength of the Earth's Crust

Cited by 142 publications

References 2 publications

An attempt to detect temporal variations of crustal structure in the source area of the 2006 Wen-An earthquake in North China

An attempt to detect temporal variations of crustal structure in the source area of the 2006 Wen-An earthquake in North China

Seismicity and rates of relative motion on the plate boundaries of Western North America

Fine three-dimensional P-wave velocity structure beneath the capital region and deep environment for the nucleation of strong earthquakes

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