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1.
ＴｈｅｅｆｅｃｔｏｆｆｏｃａｌｄｅｐｔｈｅｒｏｒｏｎｍｏｍｅｎｔｔｅｎｓｏｒｉｎｖｅｒｓｉｏｎＬＩＳＨＥＮＧＸＵ（许力生）ＹＵＮＴＡＩＣＨＥＮ（陈运泰）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ...  相似文献   

2.
ＳｉｍｕｌａｔｉｏｎｏｆｔｈｅａｃｔｉｖｅａｎｄｑｕｉｅｔｐｅｒｉｏｄｓｏｆｓｅｉｓｍｉｃｉｔｙＺＨＯＮＧ－ＸＭＮＨＵＡＮＧ（黄忠贤）（ＩｎｓｔｉｔｕｔｅｏｆＣｒｕｓｔａｌＤｙｎａｍｉｃｓ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅｉｊｉ...  相似文献   

3.
Ｔｈｅｏｒｉｇｉｎｏｆｔｈｅｃｒｕｓｔａｌｃｏｎｄｕｃｔｉｖｅｌａｙｅｒａｎｄｔｈｅｃｏｎｄｕｃｔｉｖｉｔｙｏｆｓｕｐｅｒｃｒｉｔｉｃａｌｂｒｉｎｅ（Ⅱ）ＣＨＡＮＧ－ＦＡＮＧＸＵ（徐常芳）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙ，ＳｔａｔｅＳｅｉｓｍｏ...  相似文献   

4.
ＬｏａｄｔｉｄｅｈｅａｔｉｎｇｍｅｃｈａｎｉｓｍｏｆｏｃｅａｎｉｃｈｏｔｓｐｏｔｓＳＨＵＮ－ＬＩＡＮＧＣＨＩ１）（池顺良），ＱＩＮ－ＷＥＮＸＩ２）（郗钦文），ＭＩＮＧ－ＪＩＮＬＵＯ３）（骆鸣津）ａｎｄＬＩＡＮＧＣＨＩ１）（池亮）１）Ｓｅｉｓｍｏｌｇ...  相似文献   

5.
Ｓｔｕｄｙｏｆａ３ＤｓｅｉｓｍｉｃｇａｐＹＵＡＮＱＩＮＧＺＨＵ１）（朱元清）ＣＯＮＧＪＵＮＸＩＡ１）（夏从俊）ＧＥＴＵＺＵＯＬＩ２）（左力格图）ＨＵＩＭＩＮＬＩ１）（李慧民）１）ＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕｏｆＳｈａｎｇｈａｉ，...  相似文献   

6.
Ｓｉｍｕｌｔａｎｅｏｕｓｉｎｖｅｒｓｉｏｎｏｆｖｅｌｏｃｉｔｙｄｉｓｔｒｉｂｕ┐ｔｉｏｎａｎｄｉｎｔｅｒｆａｃｅｐｏｓｉｔｉｏｎｓＳＯＮＧ－ＬＩＮＬＩ１）（李松林）ＮＩＮＧ－ＹＵＡＮＷＵ２）（吴宁远）ＺＨＡＮ－ＬＯＮＧＳＯＮＧ１）（宋占隆）ＪＩＮ－...  相似文献   

7.
Fractal　research　of　fault　gouge   总被引：1，自引：0，他引：1  
ＦｒａｃｔａｌｒｅｓｅａｒｃｈｏｆｆａｕｌｔｇｏｕｇｅＳＨＵＮ－ＭＥＩＳＨＡＯ（邵顺妹）ａｎｄＪＩＮ－ＣＨＡＮＧＺＯＵ（邹瑾敞）ＥａｒｔｈｑｕａｋｅＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＬａｎｚｈｏｕ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａ...  相似文献   

8.
Inversion of Q value structure beneath the Tibet Plateau   总被引：1，自引：0，他引：1  
ＩｎｖｅｒｓｉｏｎｏｆＱｖａｌｕｅｓｔｒｕｃｔｕｒｅｂｅｎｅａｔｈｔｈｅＴｉｂｅｔＰｌａｔｅａｕＪＩＡＮ－ＰＩＮＧＷＵ（吴建平）ａｎｄＲＯＮＧ－－ＳＨＥＮＧＺＥＮＧ（曾融生）（ＩｎｓｔｉｔｕｔｅｆｏＧｅｏｐｈｙｓｉｃｓＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃ...  相似文献   

9.
ＳｏｍｅｇｅｏｌｏｇｉｃｓｉｇｎａｔｕｒｅｓｏｆｆａｕｌｔｃｒｅｐｉｎｔｈｅｃｏｎｔｉｎｅｎｔａｌａｒｅａｏｆＣｈｉｎａＨＯＮＧＦＡＸＩＡＮＧ（向宏发）ＳＨＵＮＭＩＮＧＵＯ（虢顺民）ＷＡＮＸＩＡＺＨＡＮＧ（张晚霞）ＢＩＮＧＬＩＡＮＧＺＨＡＮ...  相似文献   

10.
ＧｅｏｇｒａｐｈｉｃａｌｄｉｓｔｒｉｂｕｔｉｏｎｏｆｈｙｐｏｃｅｎｔｒａｌｄｅｐｔｈｓｏｆＣｈｉｎｅｓｅｅａｒｔｈｑｕａｋｅｓＸＩＮＧ－ＢＥＩＤＵＡＮ（段星北）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓｉｃａｌ，ＳｔａｔｅＳｅｉｓｍｏｌｏｇｉｃａｌＢｕｒ...  相似文献   

11.
TheM s =6.9 Gonghe, China, earthquake of April 26, 1990 is the largest earthquake to have been documented historically as well as recorded instrumentally in the northeastern Qinghai-Xizang (Tibetan) plateau. The source process of this earthquake and the tectonic stress field in the northeastern Qinghai-Xizang plateau are investigated using geodetic and seismic data. The leveling data are used to invert the focal mechanism, the shape of the slipped region and the slip distribution on the fault plane. It is obtained through inversion of the leveling data that this earthquake was caused by a mainly reverse dip-slipping buried fault with strike 102°, dip 46° to SSW, rake 86° and a seismic moment of 9,4×1018 Nm. The stress drop, strain and energy released for this earthquake are estimated to be 4.9 MPa, 7.4×10–5 and 7.0×1014 J, respectively. The slip distributes in a region slightly deep from NWW to SEE, with two nuclei, i.e., knots with highly concentrated slip, located in a shallower depth in the NWW and a deeper depth in the SEE, respectively.Broadband body waves data recorded by the China Digital Seismograph Network (CDSN) for the Gonghe earthquake are used to retrieve the source process of the earthquakes. It is found through moment-tensor inversion that theM s =6.9 main shock is a complex rupture process dominated by shear faulting with scalar seismic moment of the best double-couple of 9.4×1018 Nm, which is identical to the seismic moment determined from leveling data. The moment rate tensor functions reveal that this earthquake consists of three consecutive events. The first event, with a scalar seismic moment of 4.7×1018 Nm, occurred between 0–12 s, and has a focal mechanism similar to that inverted from leveling data. The second event, with a smaller seismic moment of 2.1×1018 Nm, occurred between 12–31 s, and has a variable focal mechanism. The third event, with a sealar seismic moment of 2.5×1018 Nm, occurred between 31–41 s, and has a focal mechanism similar to that inverted from leveling data. The strike of the 1990 Gonghe earthquake, and the significantly reverse dip-slip with minor left-lateral strike-slip motion suggest that the pressure axis of the tectonic stress field in the northeastern Qinghai-Xizang plateau is close to horizontal and oriented NNE to SSW, consistent with the relative collision motion between the Indian and Eurasian plates. The predominant thrust mechanism and the complexity in the tempo-spatial rupture process of the Gonghe earthquake, as revealed by the geodetic and seismic data, is generally consistent with the overall distribution of isoseismals, aftershock seismicity and the geometry of intersecting faults structure in the Gonghe basin of the northeastern Qinghai-Xizang plateau.Contribution No. 96 B0006 Institute of Geophysics, State Seismological Bureau, Beijing, China.  相似文献   

12.
    
An earthquake ofM S=6.9 occurred at the Gonghe, Qinghai Province, China on April 26, 1990. Three larger aftershocks took place at the same region,M S=5.5 on May 7, 1990,M S=6.0 on Jan. 3, 1994 andM S=5.7 on Feb. 16, 1994. The long-period recordings of the main shock from China Digital Seismograph Network (CD-SN) are deconvolved for the source time functions by the correspondent recordings of the three aftershocks as empirical Green’s functions (EGFs). No matter which aftershock is taken as EGF, the relative source time functions (RSTFs) obtained are nearly identical. The RSTFs suggest theM S=6.9 event consists of at least two subevents with approximately equal size whose occurrence times are about 30 s apart, the first one has a duration of 12 s and a rise time of about 5 s, and the second one has a duration of 17 s and a rise time of about 8 s. Comparing the RSTFs obtained from P- and SH-phases respectively, we notice that those from SH-phases are a slightly more complex than those from P-phases, implying other finer subevents exist during the process of the main shock. It is interesting that the results from the EGF deconvolution of long-period wavform data are in good agreement with the results from the moment tensor inversion and from the EGF deconvolution of broadband waveform data. Additionally, the two larger aftershocks are deconvolved for their RSTFs. The deconvolution results show that the processes of theM S=6.0 event on Jan. 3, 1994 and theM S=5.7 event on Feb. 16, 1994 are quite simple, both RSTFs are single impulses. The RSTFs of theM S=6.9 main shock obtained from different stations are noticed to be azimuthally dependent, whose shapes are a slightly different with different stations. However, the RSTFs of the two smaller aftershocks are not azimuthally dependent. The integrations of RSTFs over the processes are quite close to each other, i. e., the scalar seismic moments estimated from different stations are in good agreement. Finally the scalar seismic moments of the three aftershocks are compared. The relative scalar seismic moment of the three aftershocks deduced from the relative scalar seismic moments of theM S=6.9 main shock are very close to those inverted directly from the EGF deconvolution. The relative scalar seismic moment of theM S=6.9 main shock calculated using the three aftershocks as EGF are 22 (theM S=6.0 aftershock being EGF), 26 (theM S=5.7 aftershock being EGF) and 66 (theM S=5.5 aftershock being EGF), respectively. Deducing from those results, the relative scalar sesimic moments of theM S=6.0 to theM S=5.7 events, theM S=6.0 to theM S=5.5 events and theM S=5.7 to theM S=5.5 events are 1.18, 3.00 and 2.54, respectively. The correspondent relative scalar seismic moments calculated directly from the waveform recordings are 1.15, 3.43, and 3.05. Contribution No. 96B0007, Institute of Geophysics, SSB, China.  相似文献   

13.
The December 26, 2004 Sumatra–Andaman Island earthquake, which ruptured the Sunda Trench subduction zone, is one of the three largest earthquakes to occur since global monitoring began in the 1890s. Its seismic moment was M 0 = 1.00 × 1023–1.15 × 1023 Nm, corresponding to a moment-magnitude of M w = 9.3. The rupture propagated from south to north, with the southerly part of fault rupturing at a speed of 2.8 km/s. Rupture propagation appears to have slowed in the northern section, possibly to ∼2.1 km/s, although published estimates have considerable scatter. The average slip is ∼5 m along a shallowly dipping (8°), N31°W striking thrust fault. The majority of slip and moment release appears to have been concentrated in the southern part of the rupture zone, where slip locally exceeded 30 m. Stress loading from this earthquake caused the section of the plate boundary immediately to the south to rupture in a second, somewhat smaller earthquake. This second earthquake occurred on March 28, 2005 and had a moment-magnitude of M w = 8.5.  相似文献   

14.
An earthquake ofM S=6.9 occurred at the Gonghe, Qinghai Province, China on April 26, 1990. Three larger aftershocks took place at the same region,M S=5.5 on May 7, 1990,M S=6.0 on Jan. 3, 1994 andM S=5.7 on Feb. 16, 1994. The long-period recordings of the main shock from China Digital Seismograph Network (CD-SN) are deconvolved for the source time functions by the correspondent recordings of the three aftershocks as empirical Green’s functions (EGFs). No matter which aftershock is taken as EGF, the relative source time functions (RSTFs) obtained are nearly identical. The RSTFs suggest theM S=6.9 event consists of at least two subevents with approximately equal size whose occurrence times are about 30 s apart, the first one has a duration of 12 s and a rise time of about 5 s, and the second one has a duration of 17 s and a rise time of about 8 s. Comparing the RSTFs obtained from P- and SH-phases respectively, we notice that those from SH-phases are a slightly more complex than those from P-phases, implying other finer subevents exist during the process of the main shock. It is interesting that the results from the EGF deconvolution of long-period wavform data are in good agreement with the results from the moment tensor inversion and from the EGF deconvolution of broadband waveform data. Additionally, the two larger aftershocks are deconvolved for their RSTFs. The deconvolution results show that the processes of theM S=6.0 event on Jan. 3, 1994 and theM S=5.7 event on Feb. 16, 1994 are quite simple, both RSTFs are single impulses. The RSTFs of theM S=6.9 main shock obtained from different stations are noticed to be azimuthally dependent, whose shapes are a slightly different with different stations. However, the RSTFs of the two smaller aftershocks are not azimuthally dependent. The integrations of RSTFs over the processes are quite close to each other, i. e., the scalar seismic moments estimated from different stations are in good agreement. Finally the scalar seismic moments of the three aftershocks are compared. The relative scalar seismic moment of the three aftershocks deduced from the relative scalar seismic moments of theM S=6.9 main shock are very close to those inverted directly from the EGF deconvolution. The relative scalar seismic moment of theM S=6.9 main shock calculated using the three aftershocks as EGF are 22 (theM S=6.0 aftershock being EGF), 26 (theM S=5.7 aftershock being EGF) and 66 (theM S=5.5 aftershock being EGF), respectively. Deducing from those results, the relative scalar sesimic moments of theM S=6.0 to theM S=5.7 events, theM S=6.0 to theM S=5.5 events and theM S=5.7 to theM S=5.5 events are 1.18, 3.00 and 2.54, respectively. The correspondent relative scalar seismic moments calculated directly from the waveform recordings are 1.15, 3.43, and 3.05.  相似文献   

15.
Source mechanism and source parameters of May 28, 1998 earthquake,Egypt   总被引：1，自引：0，他引：1  
On May 28, 1998, a moderate size earthquake of mb 5.5 occurred offshore the northwestern part of Egypt (latitude 31.45°N and longitude 27.64°E). It was widely felt in the northern part of Egypt. Being the largest well-recorded event in the area for which seismic data from the global digital network are available, it provides an excellent opportunity to study the tectonic process and present day stress field occurring along the offshore Egyptian coast. The source parameters of this event are determined using three different techniques: modeling of surface wave spectral amplitudes, regional waveform inversion, and teleseismic body waveform inversion. The results show a high-angle reverse fault mechanism generally trending NNW–SSE. The P-axis trends ENE–WSW consistently with the prevailed compression stress along the southeastern Hellenic arc and southwestern part of the Cyprean arc. This unexpected mechanism is most probably related to a positive inversion of the NW trending offshore normal faults and confirms an extension of the back thrusting effects towards the African margin. The estimated focal depth ranges from 22 to 25 km, indicating a lower crustal origin earthquake owing to deep-seated tectonics. The source time function indicates a single source with rise time and total rupture duration of 2 and 5 s, respectively. The seismic moment (M o) and the moment magnitude (M w) determined by the three techniques are 1.03 × 1017 Nm, 5.28; 1.24 × 1017 Nm, 5.33; and 1.68 × 1017 Nm, 5.42; respectively. The calculated fault radius, stress drop, and the average dislocation assuming a circular fault model are 7.2 km, 0.63 Mpa, and 0.11 m, respectively.  相似文献   

16.
Spectral parameters have been estimated for 214 Petatlan aftershocks recorded at stations between Petatlan and Mexico City and between Petatlan and Acapulco. The spectral parameters were used to obtain empirical relations for the estimation of seismic moment from coda length and fromM L . Stress drops, using Brune's model, were calculated for these aftershocks. Six events with large stress drop are located within a previously suggested asperity, and seven more suggest a boundary zone at the intersection of the Petatlan and Zihuatanejo aftershock rupture volumes. Stress drops increase with increasing seismic moment up to 1020 dyne-cm but appear to be constant at greater moment values. The peak horizontal velocity times distance of aftershocks recorded near the coast and between the coast and Mexico City (30 to 270 km away), scales linearly with seismic moment, and predicts well the peak horizontal values of large (M s 7.0) coastal thrust events recorded on rock sites at Mexico City. Peak horizontal velocity is a straightforward measurement, thus this relation allows us to evaluate expected ground motion between the Pacific coast and Mexico City from the seismic moment of subduction related earthquakes along the coast.  相似文献   

17.
The April 20, 2013 Lushan earthquake which occurred in Sichuan, China had only moderate thrust. However, the computed seismic moments (M 0) for the Lushan earthquake calculated by several institutions differ significantly from 0.4 × 1019 to 1.69 × 1019 Nm, up to four times difference. We evaluate ten computed M 0s by using normal mode observations from superconducting gravimeters in Mainland China. We compute synthetic normal modes on the basis of moment tensor solutions and fit them to the observed normal modes. Comparison of our results indicates that M 0 is the main cause for some large differences between observations and synthetics. We suggest that a moment magnitude of M w6.6, corresponding to a M 0 of 0.97–1.08 × 1019 Nm, characterizes the size and strength of the seismic source of the Lushan earthquake.  相似文献   

18.
Source parameters of the earthquakes of the Baikal rift system   总被引：1，自引：0，他引：1  
The dynamic parameters of the earthquake source—the seismic moment, the moment magnitude, the source radius, the stress drop, and the amplitude of displacement—are determined by the amplitude Fourier spectra of the body shear waves (S-waves) for 62 earthquakes of the Baikal rift system with the energy class of K P = 9.1–15.7. In the calculations I used the classical Brune model. The seismic moment of the earthquakes being investigated changes from 3.65 × 1011 N m to 1.35 × 1018 N m, and the radii of earthquake sources vary from 390 m to 1.84 km. The values of the drop in stress Δσ grow with an increase in the seismic moment up to 1.7 × 108 Pa. For the group of weak earthquakes (M w = 1.7–3.3), extremely low values of the drop in stress 103–104 Pa are observed. The maximum amplitude of displacement in the source amounts to 5.95 m. The empirical equations between the seismic moment and the other dynamic parameters of the source are determined. The regional dependence of the seismic moment and energy class is obtained: log M 0 ± 0.60 = 1.03K P + 3.17. The character of the relationship between the seismic moment and the corner frequency indicates that the classical scaling law of the seismic spectrum for the earthquakes in question is not fulfilled. The obtained estimates of the dynamic parameters are in satisfactory agreement with the published data concerning the analogous parameters of the other rift zones, which reflects the general regular patterns of the destruction of the lithosphere and the seismicity in the extension zones of the lithosphere.  相似文献   

19.
The 2018,Songyuan,Jilin M_S5. 7 earthquake occurred at the intersection of the FuyuZhaodong fault and the Second Songhua River fault. The moment magnitude of this earthquake is M_W5. 3,the centroid depth by the waveform fitting is 12 km,and it is a strike-slip type event. In this paper,with the seismic phase data provided by the China Earthquake Network, the double-difference location method is used to relocate the earthquake sequence,finally the relocation results of 60 earthquakes are obtained. The results show that the aftershock zone is about 4. 3km long and 3. 1km wide,which is distributed in the NE direction. The depth distribution of the seismic sequence is 9km-10 km. 1-2 days after the main shock,the aftershocks were scattered throughout the aftershock zone,and the largest aftershock occurred in the northeastern part of the aftershock zone. After 3-8 days,the aftershocks mainly occurred in the southwestern part of the aftershock zone. The profile distribution of the earthquake sequence shows that the fault plane dips to the southeast with the dip angle of about 75°. Combined with the regional tectonic setting,focal mechanism solution and intensity distribution,we conclude that the concealed fault of the Fuyu-Zhaodong fault is the seismogenic fault of the Songyuan M_S5. 7 earthquake. This paper also relocates the earthquake sequence of the previous magnitude 5. 0 earthquake in 2017. Combined with the results of the focal mechanism solution,we believe that the two earthquakes have the same seismogenic structure,and the earthquake sequence generally develops to the southwest. The historical seismic activity since 2009 shows that after the magnitude 5. 0 earthquake in 2017,the frequency and intensity of earthquakes in the earthquake zone are obviously enhanced,and attention should be paid to the development of seismic activity in the southwest direction of the earthquake zone.  相似文献   

20.
The source process of February 3, 1996 Lijiang earthquake in Yunnan was studied by body waveform inversion using teleseismic data from IRIS. Two normal double-couple subevents with different strikes were obtained. The difference of the onset time between these two subevents, which are 15 km apart in space, is 7 s. The total seismic moment is 3.81 × 1018 Nm (M w=6.3). The total fault area S is about 720 km2 from the aftershock data and the average dislocation is about ū=0.18 m. Considering both the result of inversion and tectonic environment around the source, the first rupture might result from the extension along the NNW directed Zhongdian-Yongsheng fault belt where an earthquake of M=6.4 occurred in 1966. Then, the second started along the NE directed the eastern foot of Snow Mountain fault where rupture seemed to be able to propagate more easily.  相似文献   

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