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1.
This paper presents new data on the upper mantle characteristics, and on seismicity and volcanism in Kamchatka. It is shown that the seismic activity in the Pacific focal layer decreases sharply below that narrow line on which the foci of the active volcanoes are situated. A map of longitudinal wave velocitiesV p in the mantle upper layers under Kamchatka is given. The lowest values ofV p (7.3–7.6 km/sec) are found near the volcanic belt. The graphs Θ=lg (Es/Ep) (h) for the Kamchatka earthquakes indicate that Θmin at the depths of 120–250 km may be caused by a concentration of magmatic melts. A map of bodies (magma chambers?) screening S- and P-waves at the depths of 30–100 km under Kamchatka has been compiled. These bodies are mainly located under the belt of active volcanoes. 相似文献
2.
A seismological study of the upper mantle under the Kamchatka volcanoes using body waves from nearby earthquakes has shown local heterogencities consisting of materials with reduced elastic properties at depths from 30 to 90 km. The estimated value of the upper limit of viscosity,η, is about 6 × 1020 pois for the material of the mantle aseismic zone under the Kamchatka volcanoes at depths of ～ 70–150 km. It is suggested that the magmatic chambers are rooted in the mantle heterogeneities filled with substance of reduced elasticity and viscosity. 相似文献
3.
L. P. Vinnik I. M. Aleshin M. K. Kaban S. G. Kiselev G. L. Kosarev S. I. Oreshin Ch. Reigber 《Izvestiya Physics of the Solid Earth》2006,42(8):639-651
A 3-D velocity model of the Tien Shan crust and upper mantle is constructed through the inversion of the receiver functions of P and S waves together with teleseismic traveltime anomalies at nearly 40 local seismic stations. It is found that in the vast central region, where no strong earthquakes have been known over the past century, the S wave velocity at depths of 10–35 km is lower than in adjacent regions by up to 10%. These data are evidence for mechanical weakness of the crust preventing the accumulation of elastic energy. Apparently, the lower velocity and the weakness of the crust are due to the presence of water. The weakness of the crust is one of the possible reasons for the strain localization responsible for the formation of the present Tien Shan but can also be due in part to the young orogenesis. The crustal thickness is largest (about 60 km) in the Tarim-Tien Shan junction zone. The crust-mantle boundary in this region descends by a jump as a result of an increase in the lower crust thickness. This is probably due to the underthrusting of the Tien Shan by the Tarim lithosphere. This causes the mechanically weak lower crust of the Tarim to delaminate and accumulate in nearly the same way as an accretionary prism during the subduction of oceanic lithosphere. In the upper mantle, the analysis has revealed a low velocity anomaly, apparently related to basaltic outflows of the Upper Cretaceous-Early Paleogene. The Cenozoic Bachu uplift in the northern Tarim depression is also associated with the low velocity anomaly. The Naryn depression is characterized by a high velocity in the upper mantle and can be interpreted as a fragment of an ancient platform. 相似文献
4.
本文利用天然地震面波记录和层析成像方法,研究了南北地震带及邻近区域的岩石圈S波速度结构和各向异性特征.结果表明南北地震带的东边界不但是地壳厚度剧变带,也是地壳速度的显著分界.其西侧中下地壳的S波速度显著低于东侧,强震大多发生在低速区内部和边界.青藏高原东缘中下地壳速度显著低于正常大陆地壳,在松潘甘孜地块和川滇地块西部大约25～45 km深度存在壳内低速层;这些低速特征与高原主体的低速区相连,有利于下地壳物质的侧向流动.地壳的各向异性图像与下地壳流动模式相符,即下地壳物质绕喜马拉雅东构造结运动,东向的运动遇到扬子坚硬地壳阻挡而变为向南和向北东的运动.面波层析成像结果支持青藏高原地壳运动的下地壳流动模型.南北地震带的岩石圈厚度与其东侧的扬子和鄂尔多斯地块相似但速度较低.川滇西部地块上地幔顶部(莫霍面至88 km左右)异常低速;松潘甘孜地块上地幔盖层中有低速夹层(约90～130 km深度).岩石圈上地幔的速度分布图像与地壳显著不同,在高原主体与川滇之间存在北北东向高速带,可能会阻挡地幔物质的东向运动.上地幔各向异性较弱且与地壳的分布图像显然不同.因此青藏高原岩石圈地幔的构造运动具有与地壳不同的模式,软弱的下地壳提供了壳幔运动解耦的条件. 相似文献
5.
The presence of a phenomenological relationship between high velocity regions in the Benioff zone and sources of relatively strong earthquakes (M ≥ 6) was established for the first time from the comparison of such earthquakes with the velocity structure of central Kamchatka in the early 1970s. It was found that, in the region with P wave velocities of 8.1–8.5 km/s, the number of M ≥ 6 earthquakes over 1926–1965 was 2.5 times greater than their number in the region with velocities of 7.5–8.0 km/s. Later (in 1979), within the southern Kurile area, Sakhalin seismologists established that regions with V P = 7.3–7.7 km/s are associated with source zones of M = 7.0–7.6 earthquakes and regions with V P = 8.1–8.4 km/s are associated with M = 7.9–8.4 earthquakes. In light of these facts, we compared the positions of M = 7.0–7.4 earthquake sources in the Benioff zone of southern Kamchatka over the period 1907–1993 with the distribution of regions of high P velocities (8.0–8.5 to 8.5–9.0 km/s) derived from the interpretation of arrival time residuals at the Shipunskii station from numerous weak earthquakes in this zone (more than 2200 events of M = 2.3–4.9) over the period 1983–1995. This comparison is possible only in the case of long-term stability of the velocity field within the Benioff zone. This stability is confirmed by the relationship between velocity parameters and tectonics in the southern part of the Kurile arc, where island blocks are confined to high velocity regions in the Benioff zone and the straits between islands are confined to low velocity regions. The sources of southern Kamchatka earthquakes with M = 7.0–7.4, which are not the strongest events, are located predominantly within high velocity regions and at their boundaries with low velocity regions; i.e., the tendency previously established for the strongest earthquakes of the southern Kuriles and central Kamchatka is confirmed. However, to demonstrate more definitely their association with regions of high P wave velocities, a larger statistics of such earthquakes is required. On the basis of a direct correlation between P wave velocities and densities, the distributions of density, bulk modulus K, and shear modulus μ in the upper mantle of the Benioff zone of southern Kamchatka are obtained for the first time. Estimated densities vary from 3.6–3.9 g/cm3 in regions of high V P values to 3.0–3.2 g/cm3 for regions of low V P values. The bulk modulus K in the same velocity regions varies from (1.4–1.8) × 1012 to (0.8–1.1) × 1012 dyn/cm2, respectively, and the shear modulus μ varies from (0.8–1.0) × 1012 to (0.5–0.7) × 1012 dyn/cm2, respectively. Examination of the spatial correlation of the source areas of southern Kamchatka M = 7.0–7.4 earthquakes with the distribution of elastic moduli in the Benioff zone failed to reveal any relationship between their magnitudes and the moduli because of the insufficient statistics of the earthquakes used. 相似文献
6.
本文使用10个工业爆破和154个天然地震,以及四川台网50个台站记录的 P 波组到时等资料,以龙门山断裂和二次大地构造单元分界线为界(图1),得出四川东部盆地和西部高原不同的地壳上地幔平均速度模型.若简单地采用双层地壳模型,则东部地壳厚40-41km,壳下 P 波速度为8.15-8.2km/s,壳内上层平均速度为5.82-5.9km/s,厚18km,下层平均速度为6.47-6.54km/s,厚22-23km;西部地壳厚61-64km,壳下 P 波速度为7.8-7.84km/s,壳内上层平均速度为5.82-5.98km/s,厚27-28.5km,下层平均速度为6.94-7.0km/s,厚34-35.5km.此模型为四川地区走时表提供了依据,也为研究地壳上地幔结构与地震的关系,研究我国大陆地块的构造演化及形成等,提供了有用的约束. 相似文献
7.
利用双差地震定位方法对鄂尔多斯东缘地区（34°N-41°N,110°E-115°E）2008年1月-2012年12月的中小地震进行了重新定位.重定位后,定位精度得到改善,震中分布更加集中.鄂尔多斯东缘拉张盆地内部震源深度较浅,大多小于13 km,向盆地两端震源深度有加深的趋势,特别是太原盆地北端,临汾盆地北端,以及运城与临汾盆地之间的峨眉台地,震源深度可达20~25 km左右.我们认为盆地内部地壳减薄,上地幔上隆,热作用导致地壳内部脆性层减薄,致使最大震源深度变浅;盆地之间的横向隆起区受区域应力场挤压剪切作用以及盆地内部上地幔上拱产生的水平向挤压力作用等,在横向隆起区与盆地接触带易产生应力集中,导致地震的发生,由于受脆性层厚度变化等的影响,在盆地向横向隆起区过渡部位出现震源深度加深的现象.鄂尔多斯东北缘地区地震分布弥散、震源深度相对较浅,可能与源自地幔的大范围深部热作用以及地壳脆性层厚度减薄有关.根据地震的空间分布特征,对部分盆地内部的断层特征进行了讨论. 相似文献
8.
S. T. Balesta A. I. Farberov V. S. Smirnov A. A. Tarakanovsky M. I. Zubin 《Bulletin of Volcanology》1977,40(4):260-266
Crustal structure in a number of Kamchatka volcanic regions is deduced from geophysical data. Anomalous structure and physical properties of the crust are found beneath some volcanic groups. Beneath the Klyuchevskaya and Avachinskaya volcanic groups crustal layers have high elastic properties. There is a thick transition layer from the crust to the upper mantle which has lower clastic properties and electrical resistance. These data, supported by experimental investigations of elastic properties of xenoliths in volcanic rocks at high pressures and temperatures, enable the probable substance composition of the crustal layers to be defined. The feeding zones and magma chambers of individual volcanoes are deduced from anomalies in gravity, electrical conductivity and seismic wave propagation. 相似文献
9.
Two-dimensional crustal velocity models are derived from passive seismic observations for the Archean Karelian bedrock of north-eastern Finland. In addition, an updated Moho depth map is constructed by integrating the results of this study with previous data sets. The structural models image a typical three-layer Archean crust, with thickness varying between 40 and 52 km. P wave velocities within the 12–20 km thick upper crust range from 6.1 to 6.4 km/s. The relatively high velocities are related to layered mafic intrusive and volcanic rocks. The middle crust is a fairly homogeneous layer associated with velocities of 6.5–6.8 km/s. The boundary between middle and lower crust is located at depths between 28 and 38 km. The thickness of the lower crust increases from 5–15 km in the Archean part to 15–22 km in the Archean–Proterozoic transition zone. In the lower crust and uppermost mantle, P wave velocities vary between 6.9–7.3 km/s and 7.9–8.2 km/s. The average Vp/Vs ratio increases from 1.71 in the upper crust to 1.76 in the lower crust.The crust attains its maximum thickness in the south-east, where the Archean crust is both over- and underthrust by the Proterozoic crust. A crustal depression bulging out from that zone to the N–NE towards Kuusamo is linked to a collision between major Archean blocks. Further north, crustal thickening under the Salla and Kittilä greenstone belts is tentatively associated with a NW–SE-oriented collision zone or major shear zone. Elevated Moho beneath the Pudasjärvi block is primarily explained with rift-related extension and crustal thinning at ∼2.4–2.1 Ga.The new crustal velocity models and synthetic waveform modelling are used to outline the thickness of the seismogenic layer beneath the temporary Kuusamo seismic network. Lack of seismic activity within the mafic high-velocity body in the uppermost 8 km of crust and relative abundance of mid-crustal, i.e., 14–30 km deep earthquakes are characteristic features of the Kuusamo seismicity. The upper limit of seismicity is attributed to the excess of strong mafic material in the uppermost crust. Comparison with the rheological profiles of the lithosphere, calculated at nearby locations, indicates that the base of the seismogenic layer correlates best with the onset of brittle to ductile transition at about 30 km depth.We found no evidence on microearthquake activity in the lower crust beneath the Archean Karelian craton. However, a data set of relatively well-constrained events extracted from the regional earthquake catalogue implies a deeper cut-off depth for earthquakes in the Norrbotten tectonic province of northern Sweden. 相似文献
10.
A total of 11 earthquakes with 15 Rayleigh wave paths, recorded at 11 broadband digital PASSCAL seismometers installed in the Tibet Plateau by the Sino-U.S. joint research group, were used to determine the phase velocity and attenuation coefficient of surface waves in periods of 10–130 s. The average shear wave velocity and quality factor {ie271-1} structures in the crust and upper mantle were obtained in this region. The result shows the average {ie271-2} is low and there exists a high attenuation ({ie271-3}=93–141) layer in the crust. The depth range of the low {ie271-4} value layer (16–42 km) is consistent with the range of low velocity layer (21–51 km) in the crust. Below 63 km in the lower crust, {ie271-5} decreases with depth from 114 to 34 at depth of 180 km. The low shear wave velocity and low value of {ie271-6} at the same depth range in the crust indicate that the rocks in the range is probably melted or partially melted. According to the shear wave velocity structure, the average thickness of the crust is about 71 km and a clear velocity discontiniuty appears at the depth of 51 km. The low-velocity zone (4. 26 km/s) at depth of 96–180 km may be corresponding to the asthenosphere. 相似文献
11.
分别利用纯S波波形反演和T函数法计算了太行山构造带及其邻近地区100km以上的壳幔剪切波速度结构,结果显示太行山构造带在南、中、北段的壳幔结构存在明显差异。南段邢台邯郸地区地壳中比较突出的特点是下地壳存在一个厚度近10km的低速层;中段石家庄—保定地区靠近山脉的各台地壳结构相对比较稳定,越向盆地区发展,结构愈加复杂化;北段到达北京地区,由于该区是太行山与燕山构造带的交汇地区,中下地壳出现薄高低速转换层位,呈现不稳定状态。沿太行山构造带东缘是地震活动带-河北平原地震带,通过对比速度结构与地震空间分布,发现不同区段小震分布特点与地下低速或不稳定结构关系密切。结合该区域上地幔速度结构特征,认为太行山中段与华北地区中新生代以来的岩石圈大规模减薄运动关系密切,而南北两段当前地幔物质比较活跃,构造运动相对更为强烈。 相似文献
12.
Summary The crustal structure beneath the Himalayas has been investigated using body wave data from near earthquakes having epicentres over the Himalayas and recorded by the observatories situated over, or very near, the foothills of the mountains. A three-layered crustal model, without the top sedimentary layer, with velocities for theP wave group in Granite I, Granite II and the Basaltic layer as 5.48, 6.00 and 6.45 and for theS wave group as 3.33, 3.56 and 3.90 km/sec respectively, has been interpreted. The upper mantle velocity for theP wave has been observed to be 8.07 km/sec and for theS wave as 4.57 km/sec. Average thickness for the Granite I layer has been computed as 22.7 km, for the Granite II layer as 16.3 km and for the Basaltic layer as 18.7 km. Crustal and sub-crustal velocities indicate a lower trend under the mountain. A thicker crust has been obtained beneath the Himalayas. 相似文献
13.
A total of 11 earthquakes with 15 Rayleigh wave paths, recorded at 11 broadband digital PASSCAL seismometers installed in
the Tibet Plateau by the Sino-U.S. joint research group, were used to determine the phase velocity and attenuation coefficient
of surface waves in periods of 10–130 s. The average shear wave velocity and quality factor {ie271-1} structures in the crust
and upper mantle were obtained in this region. The result shows the average {ie271-2} is low and there exists a high attenuation
({ie271-3}=93–141) layer in the crust. The depth range of the low {ie271-4} value layer (16–42 km) is consistent with the
range of low velocity layer (21–51 km) in the crust. Below 63 km in the lower crust, {ie271-5} decreases with depth from 114
to 34 at depth of 180 km. The low shear wave velocity and low value of {ie271-6} at the same depth range in the crust indicate
that the rocks in the range is probably melted or partially melted. According to the shear wave velocity structure, the average
thickness of the crust is about 71 km and a clear velocity discontiniuty appears at the depth of 51 km. The low-velocity zone
(4. 26 km/s) at depth of 96–180 km may be corresponding to the asthenosphere.
Contribution No. 96A0047, Institute of Geophysics, SSB, China.
This study was supported by the National Natural Science Foundation of China. 相似文献
14.
利用S波纯波形拟合法以及T函数法反演了苏鲁地区壳幔剪切波速度结构,并利用长周期P波T函数反演得到了连云港和莱阳台下方800km深度的速度结构。结果显示:(1)苏鲁地区大部分台站地壳表层及上地壳浅部速度偏高,分别对应高压、超高压物质和古老基底出露地区;(2)沿郯庐断裂带分布的台站均显示明显低速层,并具有北浅南深的特点;(3)连云港和莱阳台超深度反演结果显示两台均在150km深度下出现高速层,反映扬子板块的俯冲深度为100km以下,俯冲板片厚度在100km以上;板片拆离下沉深度甚至达到300km或者更深;(4)地震深度分布与低速层关系密切,沿郯庐断裂和烟台—五莲断裂的中小地震震源深度都比较深,有的甚至达到地壳的底部,反映这两条断裂目前切割深度都比较大,而且地幔物质相对比较活跃。 相似文献
15.
Jorge Luis De Souza 《Pure and Applied Geophysics》1991,136(2-3):245-264
The Rayleigh wave phase and group velocities in the period range of 24–39 sec, obtained from two earthquakes which occurred in northeastern brazil and which were recorded by the Brazilian seismological station RDJ (Rio de Janeiro), have been used to study crustal and upper mantle structures of the Brazilian coastal region. Three crustal and upper mantle models have been tried out to explain crustal and upper mantle structures of the region. The upper crust has not been resolved, due basically to the narrow period range of the phase and group velocities data. The phase velocity inversions have exhibited good resolutions for both lower crust and upper mantle, with shear wave velocities characteristic of these regions. The group velocity data inversions for these models have showed good results only for the lower crust. The shear wave velocities of the lower crust (3.86 and 3.89 km/sec), obtained with phase velocity inversions, are similar to that (=3.89 km/sec) found byHwang (1985) to the eastern South American region, while group velocity inversions have presented shear velocity (=3.75 km/sec) similar to that (=3.78 km/sec) found byLazcano (1972) to the Brazilian shield. It was not possible to define sharply the crust-mantle transition, but an analysis of the phase and group velocity inversions results has indicated that the total thickness of the crust should be between 30 and 39 km. The crustal and upper mantle model, obtained with phase velocity inversion, can be used as a preliminary model for the Brazilian coast. 相似文献
16.
Using the P-and S-wave arrivals from the 150 earthquakes distributed in Tibetan Plateau and its neighboring areas, recorded
by Tibetan seismic network, Sichuan seismic network, WWSSN and the mobile network situated in Tibetan Plateau, we have obtained
the average P-and S-wave velocity models of the crust and upper mantle for this region:
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, Supp., 573–579, 1992. 相似文献
| (1) | The crust of 70 km average thickness can be divided into two main layers: 16 km thick upper crust with P-wave velocity 5.55 km/s and S-wave velocity 3.25 km/s; and 54 km thick lower crust with P-wave velocity 6.52 km/s and S-wave velocity 3.76 km/s. |
| (2) | The p-wave velocity at the upper most mantle is 7.97 km/s, and the S-wave 4.55 km/s. The low velocity layer in the upper mantle occurs approximately at 140 km deep with a thickness of about 55–62 km. The prominent velocity gradient beneath the LVZ is comparable to the gradient above it. |
17.
为获得四川盆地及其邻区地壳和上地幔精细结构,并据此对该区域整体构造运动初步进行动力学解释,本研究采用接收函数、线性反演与H-kappa扫描相结合的方法,获得以下结论:研究区域地壳厚度东西向差异巨大,其厚度差高达29 km。四川盆地地表具有较厚沉积层,属于刚性块体。龙门山南段与四川盆地交接地区存在某些区域的波速比较高,推测这些地区可能存在地幔物质上涌导致地壳中铁镁质成分增加。松潘-甘孜地块的地壳厚度存在58~65 km的横向变化,中下地壳存在梯形低速层,可能由于青藏高原向东俯冲过程中遭遇四川盆地刚性块体的阻挡而引起该地块的挤压变形,该区域具有较高的波速比,综合分析推测其可能存在区域性的部分熔融。 相似文献
18.
S-wave velocity structure in Tangshan earthquake region and its adjacent areas from joint inversion of receiver functions and surface wave dispersion* 
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下载免费PDF全文 Using the seismic records of 83 temporary and 17 permanent broadband seismic stations deployed in Tangshan earthquake region and its adjacent areas (39°N–41.5°N, 115.5°E–119.5°E), we conducted a nonlinear joint inversion of receiver functions and surface wave dispersion. We obtained some detailed information about the Tangshan earthquake region and its adjacent areas, including sedimentary thickness, Moho depth, and crustal and upper mantle S-wave velocity. Meanwhile, we also obtained the vP/vS structure along two sections across the Tangshan region. The results show that: (1) the Moho depth ranges from 30 km to 38 km, and it becomes shallower from Yanshan uplift area to North China basin; (2) the thickness of sedimentary layer ranges from 0 km to 3 km, and it thickens from Yanshan uplift region to North China basin; (3) the S-wave velocity structure shows that the velocity distribution of the upper crust has obvious correlation with the surface geological structure, while the velocity characteristics of the middle and lower crust are opposite to that of the upper crust. Compared with the upper crust, the heterogeneity of the middle and lower crust is more obvious; (4) the discontinuity of Moho on the two sides of Tangshan fault suggests that Tangshan fault cut the whole crust, and the low vS and high vP/vS beneath the Tangshan earthquake region may reflect the invasion of mantle thermal material through Tangshan fault. 相似文献
19.
On the dynamics of extensional basin 总被引：2，自引：0，他引：2
Geological and geophysical data from the North China-Bohai Basin and “Basin and Range” Province were examined and compared. They are similar to each other in many respects. Surficial geological structures are characterized by a series of half-grabens with their one flank constituted by normal fault. Those extensional structures usually extend to a depth of 6–8 km. Therefore, the stress condition in the upper 8 km can be written as $$\sigma _2 > \sigma _x > \sigma _y$$ wherex, y denote the directions of maximum compression and maximum tension on the horizontal plane, whilez signifies the vertical direction. Some people think that this kind of stress condition exists through the entire crust in the extensional basin. However, the focal mechanisms of the earthquakes in the extensional basins with focal depths usually at 12–20 km are dominated by strike-slip faults. The stress condition in the focal regions can be expressed by $$\sigma _x > \sigma _z > \sigma _y .$$ Geodetic measurements conducted before and after the Tangshan earthquake in 1976 and the Xingtai earthquake in 1966 showed that both horizontal and vertical surficial deformations with magnitudes of a similar order occurred during the earthquakes. The surficial deformations during the earthquakes can be explained by a summation of the motions produced by both stress fields in the upper crust and the middle crust. Dynamical processes other than the homogeneous horizontal regional tectonic field are required to explain the vertical variation of the stress condition in the upper and middle crusts. Evidence from the seismic refractions, reflections and the three-dimensional seismic tomography from both local earthquakes and teleseismic events provide convincing evidence that magmatic intrusions from the uppermost mantle to the middle crust occur near the hypocenters of both the Tangshan and Xingtai earthquakes. The variation from the extensional stress regime at the upper crust to the compressional stress regime in the middle and lower crusts is considered to be the common feature in extensional basins. And the magmatic intrusions from the upper mantle to the middle crust observed in the extensional basin is suggested to be its genetic cause. Numerical simulations of magmatic intrusion from the uppermost mantle to the middle crust were studied. Both the intruded compression and the thermal stress due to magmatic intrusion were considered, also the viscoelasticity of the middle and lower crusts were assumed. The results successfully explain the vertical variation of the stress condition in the crust and the process producing an extensional basin. 相似文献
20.
基于四川数字地震台网记录到的该研究区域(27.5°～31.5°N,100°～104°E)103 990个地震的震相数据,运用双差层析成像方法对泸定MS6.8地震震源区及周边地区执行地震层析成像和精定位。结果表明：(1)余震序列主要分布于鲜水河断裂西南侧,长度约60 km,整体沿鲜水河断裂呈北西向展布,震源深度多集中在5～15 km,呈现出由北向南逐渐加深的迹象。根据余震序列空间分布特征及主震位置,提出鲜水河断裂东南段为发震断层,并且发现余震序列南北两端或许存在分支断层。根据背景地震的空间分布特征,推断其或许为泸定主震的前震。(2)主震的西北侧存在高速异常体,其或许阻挡了泸定地震向西北向破裂,结合鲜水河断裂东南段力学性质较弱,其滑动方向为首选的传播方向,推断泸定地震为单侧破裂,方向为东南。(3)泸定地震震源区下方30 km深度处存在弱S波低速层和高波速比,已有结果得知研究区中下地壳存在明显的高导层和低阻层,泸定主震位于热流值为65 mW·m2的大地热流等值线附近,综合推断震源区下方30 km或许存在地壳流体。同时,泸定地震发生在应力易积累,同时... 相似文献