（1）An Ms 6.0 earthquake struck Changning county, Sichuan basin, SW China on 17 June 2019, which caused huge casualties and economic losses. Four Ms greater than 5.0 events subsequently occurred around the Changning source area, three of which occurred within one week. In order to better understand the mechanism of these moderate-sized earthquakes, we determine 3-D high-resolution velocity models around the source area simultaneously relocating earthquakes using double-difference tomography. In the present study, we use a total of 53,487 P-wave and 52,527 S-wave arrival times from 8818 events recorded at 39 seismic stations. Our results show that focal depths of the Changning mainshock and most aftershocks are ~5–10 km, and they form a fault plane with a steep dip angle. Most earthquakes are underlain by the zone with low Vp, low Vs, and high Vp/Vs anomalies, reflecting the existence of fluids there. These results suggest that the Changning mainshock and other moderate-sized earthquakes might be associated with the influence of fluids that could decrease effective normal stress on the fault planes. These fluids might be related to the hot and wet mantle upwelling in the big mantle wedge due to the deep subduction of the Indian plate down to the mantle transition zone. A clear high-to-low velocity transition zone is observed at ~10 km depth beneath the Gongxian and Xingwen swarms, which matches well with the detachment layer revealed by deep seismic soundings in the area. All these results suggest that the structural contrast could control the mainshock generation and aftershock extension. （2）The Tanlu fault zone is the most significant active fault in eastern China, which generated the great 1668 Tancheng earthquake (M 8.5). It is still unclear whether or not there is a link between the great earthquake generation and the upper-mantle structure. To address this issue, we study P-wave upper-mantle tomography beneath eastern China using 44,047 teleseismic P-wave arrival times. Our results show that at depths<150 km, high-velocity (high-V) anomalies appear west of the Tanlu fault zone, whereas low-velocity (low-V) anomalies are visible east of the fault zone. Strong lateral heterogeneities are revealed along the fault zone. At depths of 230–470 km, northwest of the Tanlu fault zone, there are obvious low-V anomalies that may reflect hot and wet mantle upwelling, whereas to the east high-V anomalies are visible, which may reflect the detached Eurasian lithosphere (downwelling). In the mantle transition zone (MTZ), both high-V and low-V anomalies are revealed, and the widespread high-V anomalies may reflect the stagnant Pacific slab. Beneath the hypocenter of the 1668 Tancheng earthquake, intermittent low-V anomalies are revealed in the upper mantle down to the MTZ depth, which may reflect hot and wet mantle upwelling flow. Integrating the present results with previous findings, we deem that the Tancheng earthquake was affected by fluids from the hot and wet mantle upwelling associated with the lithospheric delamination. Complicated mantle convection, including both upwelling and downwelling flows, may occur under the Tanlu fault zone in the big mantle wedge above the stagnant Pacific slab in the MTZ. （3）Since the occurrence of the 2008 Wenchuan earthquake (Ms8.0), many researchers have conducted extensive seismological and geophysical observations and investigations and obtained important results about the Longmenshan fault zone. Crustal structure inferred from local tomography shows that seismic velocity exhibits significant changes across the Wenchuan earthquake hypocenter from the south to the north. To the south, obvious low-velocity (low-V) anomalies exist, whereas strong lateral heterogeneities are revealed to the north, which may explain why the aftershocks extend northeastward. The Wenchuan earthquake occurred at the boundary between high-velocity (high-V) and low-V anomalies and a significant low-V zone is revealed below the mainshock hypocenter, suggesting that the nucleation of the Wenchuan earthquake was related to partial melts and/or fluid effects and associated with the reduction of effective normal stress on the fault plane, due to high temperature and high pressure in the Longmenshan fault zone caused by the India-Asia collision. The upper-mantle structure inferred from teleseismic tomography shows that the Longmenshan fault zone is located in the transition zone from low-V anomalies beneath the Songpan-Ganzi block to high-V anomalies beneath the Sichuan basin. This structural feature extends down to 200−300 km depths. High-V anomalies in the mantle transition zone are connected with those in the upper mantle beneath the Burma arc, indicating that the Wenchuan earthquake could be associated with upwelling of hot and wet materials in the big mantle wedge formed by the deep subduction of the Indian plate. These results suggest that the generation of the Wenchuan earthquake was related to structural heterogeneities in not only the crust but also the upper mantle. In addition, the Wenchuan earthquake may be related to the lower crustal flow, crustal shortening and Zipingpu Reservoir triggering.
LEI Jianshe, ZHANG Bing
The 2015 Gorkha, Nepal earthquake (Mw 7.8) ruptured the Main Himalayan Thrust (MHT) and allows direct measurements of the behavior of the continental collision zone. We study the MHT using seismic waveforms recorded by local stations that completely cover the aftershock zone (Event catalog 1.docx and Event catalog 2.docx). We obtained the velocity structure beneath the study zone (Velocity.dat). The MHT exhibits clear lateral variation along geologic strike, with the Lesser Himalayan ramp having moderate dip on the MHT beneath the mainshock area and a flatter and deeper MHT beneath the eastern end of the aftershock zone. East of the aftershock zone, seismic wave speed increases at MHT depths, perhaps due to subduction of an Indian basement ridge. A similar magnitude wave speed change occurs at the western end of the aftershock zone. These gross morphological structures of the MHT controlled the rupture length of the Gorkha earthquake.
The global seismic waveform data of magnitude 7 or above recorded by 10 seismic stations in the Himalaya region (from January 1, 2020 to December 31, 2020), including the name and location of stations, and the clear seismic waveform of each event filtered by the seismic event directory (the seismic directory is from USGS) to 10 stations. The waveform data is clipped to 100s before and 300s after the arrival of P wave, and the format is sac format. The header contains station information, event information, azimuth and other information. It is named in the form of "network. Station name. Channel. Component. D. year. Julian day - time. 000000. Event".
BAI Ling
The data include the location information of 14 seismic stations in Sichuan Basin, the teleseismic receiver function waveform (Gauss coefficient is 5.0) and the thickness and VP / vs ratio of sedimentary and bedrock layers obtained by multi-layer H-K superposition method. By selecting the epicentral distance of 30-90 degrees and the teleseismic events greater than 5.5 degrees recorded by 4 fixed stations set up by China Seismological Bureau and 10 mobile stations set up by Institute of Geology and Geophysics of Chinese Academy of Sciences from 2010 to 2012 in the study area, the time domain iterative deconvolution method is used to obtain the radial convergence function. The results show that: the thickness of sedimentary layer is mainly distributed in 4.2-7.6 km, and the wave velocity ratio is generally more than 1.87; the thickness of bedrock is mainly distributed in 33.4-41.8 km, and the wave velocity ratio is generally less than 1.74. The uploaded data provide valuable data and information for others to further study the structural characteristics of Sichuan Basin.
WEI Zigen
The data include the location information of 154 seismic stations in the middle and southern segment of Tan Lu fault zone and its adjacent area, the teleseismic receiver function waveform and the crustal S-wave velocity inversed by receiver function (Gauss coefficient is 5.0) and surface wave. By selecting 63 fixed stations set up by China Seismological Bureau and 91 mobile stations set up by Institute of Geology and Geophysics of Chinese Academy of Sciences with observation time of one year to record 30-90 degree epicentral distance and events with magnitude greater than 5.5, the time domain iterative deconvolution method of CPS program is used to extract the radial convergence function. The results show that the Moho depth and the average VP / vs ratio of the crust in the study area mainly vary in the range of 25-38km and 1.65-1.95, respectively, and the crustal structure is roughly divided into three parts from south to north along the Cretaceous tiefuling fault and Triassic Lu'an fault and their eastward extension. The uploaded data provide valuable data and information for others to further study the structural characteristics of the Tan Lu fault zone and its adjacent areas.
The data set is mainly shown in the article https://doi.org/10.1016/j.pepi.2020.106617, which includes the distribution of the average thickness of the crust and the average Vp/Vs ratio of the crust based on the h-kappa stacking of the P-wave receiver functions on 42 stations near the Dahutang mining area in Jiangxi Province. The dataset contains 1 file in DAT format: Dahutang_ moho_ vpvs.dat。 The data set can be used to show the Moho undulation feature of the Dahutang mining area, perspective the transverse distribution characteristics of crust and crustal wave velocity ratio in Dahutang polymetallic metallogenic area, and then discuss the difference of average composition of crust inside and outside the mining area.
DENG Yangfan
The data include the location information of 17 seismic stations in Hanzhong Basin and its surrounding area, the teleseismic receiver function waveform and the crustal S-wave velocity inversed by receiver function and surface wave. Among them, each station includes two receiving functions, the Gaussian coefficient is 2.0, which are in the range of 30-60 ° And 60-90 ° The waveform superimposed within the epicentral distance. Based on the epicentral distance of 30-90 degrees and teleseismic events with magnitude greater than 5.5 recorded by 6 fixed stations set up by China Seismological Bureau for 2 years (2012-2014) and 11 mobile stations set up by Institute of Surveying and Geophysics of Chinese Academy of Sciences in December 2017, the time domain iterative deconvolution method of CPS program is used to extract the receiver function. The results show that the thickness and velocity of shallow sediments are different in different areas of Hanzhong Basin, the velocity changes gently in some areas of Moho, and the distribution of the upper and lower interfaces of focal depth (4-16 km) corresponds to the bottom layer of low velocity body and the top layer of high velocity body. The uploaded data provide valuable data and information for others to further study the structural characteristics of Hanzhong Basin and its adjacent areas.
WEI Zigen
The data set is mainly shown in the article https://doi.org/10.1016/j.pepi.2019.04.003 In the study of the. In this study, 19 inversion points were selected based on the seismic stations in the Cathaysia Block. Under the constraint of shallow P-wave velocity, the joint inversion of the P-wave receiver function and surface wave dispersion was carried out, and the S-wave velocity structure under the station was obtained. The dataset contains 19 files in the format of DAT, such as cathaysia01.velocity.dat. The data set can be used to show the velocity structure of the lithosphere in the Cathaysia Block and to see the deep mechanism corresponding to a large amount of granite outcropping in the area.
DENG Yangfan
We compiled the Seismotectonic Map and Seismic Hazard Zonation Map of Central Asia using the ArcGIS platform through data collecting and digitization. The seismotectonic map of Western Asia covers Kazakhstan, Uzbekistan, Kyrgyzstan, Tajikistan and Turkmenistan. The seismotectonic map is replenished with tremendous amount published data and depicts the location, character and name of the seismogenic faults or active faults and the epicenter of earthquakes with M ≥ 5 from 1960 to 2010. The zonation map shows the mean values of peak ground acceleration (PGA) with 10% probability of being exceeded in 50 years. The two maps can not only be used in the research of active faults and seismic risks in Central Asia, but also will be applied to the seismic safety evaluation for infrastructure construction.
LUO Hao
The data set is mainly shown in the article https://doi.org/10.1016/j.pepi.2019.04.003 The study includes the distribution of the average thickness of the crust and the average velocity ratio of the crust obtained by stacking the P-wave receiver function h-kappa-c of stations in Cathaysia Block. The dataset contains one file in DAT format: Cathaysia_ moho_ vpvs.dat。 The data set can be used to show the undulation characteristics of Moho in the Cathaysia Block, to see the transverse distribution characteristics of crustal thickness and crustal wave velocity ratio in the Cathaysia Block, and to explore the difference of average crustal composition in the Cathaysia Block.
DENG Yangfan
The data include the location information of 23 seismic stations in Linfen Rift Valley and its surrounding areas and the teleseismic receiver function waveforms. By selecting the 30-90 degree epicentral distance and more than 5.5 earthquake events recorded by 23 high-frequency mobile seismic stations deployed by Institute of Surveying and Geophysics of Chinese Academy of Sciences in November 2017 with observation duration of one month, the radial convergence function is extracted by using the time domain iterative deconvolution method of CPS program. The results show that there are low velocity bodies of different scales in the middle and lower crust of Linfen rift area, and the depth of seismogenic layer increases from ~ 25km to ~ 34km from south to north, which roughly corresponds to the bottom interface of low velocity bodies in the crust; Most of the relocation earthquakes are located in the transition zone between high and low velocity bodies, one of which has a focal depth of 32km. The m7.75 Linfen earthquake is located in the high velocity body, and the M8.0 Hongdong earthquake is located at the bottom of the high velocity body. The uploaded data provide valuable data and information for others to further study the structural characteristics of Linfen Rift Valley and its adjacent areas.
WEI Zigen
The data includes earthquakes at various levels across the country from 2300 BC to 2005 AD. There are a total of more than 330,000 catalogs, each of which includes earthquake time, epicenter longitude, epicenter latitude, focal depth, positioning accuracy, and magnitude. This data was first released by the National Seismological Bureau. The China Earthquake Catalog contains a Mapinfo layer (Total_0510Time) and files with the extensions .TAB, .MAP, .DAT, .ID. Their functions are as follows: TAB: the main file, including the table data structure and entity data format fields; MAP: a geographic data file containing map objects; ID: the index file of the graphic object file (MAP); DAT: Form data file.
MA Jin
This data set is collected from the supplementary information part of the paper: Pei, S.P., Niu, F.L., Ben-Zion, Y., Sun, Q., Liu, Y.B., Xue, X.T., Su,J.R., & Shao, Z.G. (2019). Seismic velocity reduction and accelerated recovery due to earthquakes on the Longmenshan fault. Nature Geoscience. 12. 387-392. doi:10.1038/s41561-019-0347-1. This paper studies the structural evolution process of The Longmenshan fault zone located at a pronounced topographic boundary between the eastern margin of the Tibetan plateau and the western Sichuan basin. With the observations on coseismic velocity reductions and the healing phases, it is found that the healing phase of Wenchuan earthquake fracture zone accelerated significantly in response to the Lushan earthquake. This data set contains 3 tables, table names and content are as follows: Data list: The data name list of the rest tables; t1: Data of the four periods (befor Wenchuan earthquake, after Wenchuan earthquake, before Lushan earthquake, after Lushan earthquake); t2: The average velocities with error in Figure 2 in the paper for Wenchuan earthquake (WCEQ) and Lushan earthquake (LSEQ) area. See attachments for data details: Supplementary information.pdf, Seismic velocity reduction and accelerated recovery due to earthquakes on the Longmenshan fault.pdf.
PEI Shunping
The data are the radioactive isotope dating data, mineral isotope composition data and seismic wave velocity data of metamorphic rocks in the lower crust. The samples were collected from Cenozoic basalts and felsic granulite, neutral granulite and basic granulite xenoliths in Nushan area, Anhui Province, southeastern North China Craton. The U-Pb isotopic data were obtained by laser ablation inductively coupled plasma mass spectrometry. The data of mineral isotopic composition were obtained by laser ablation inductively coupled plasma mass spectrometry. Rock seismic wave data are estimated by binocular lens and calculated by empirical formula. The obtained data reconstruct the fine structure and evolution of the lower crust in the southeastern margin of North China.
PING Xianquan
The data include the cross-correlation function extracted from the continuous seismic background noise data of vertical component recorded by 54 fixed seismic stations and 17 mobile seismic stations in Jiuyishan and its adjacent area from May 2016 to June 2017, and the final inversion of crustal S-wave velocity. The dispersion curves of group velocity and phase velocity of 2-40s are obtained by time-frequency analysis. The inversion imaging results show that the structural characteristics of the crust and upper mantle of the Yangtze block and the Cathaysian Block are significantly different. The S-wave velocity distribution map of 10-20km shows linear and continuous low velocity anomalies, which may be the specific boundary between the Yangtze block and the Cathaysian Block. The imaging results provide seismological constraints for understanding the tectonic evolution history of South China. The uploaded data provide valuable data and information for others to further study the structural characteristics of Jiuyi mountain and its adjacent areas.
This data set is used to analyze the global activity level of strong earthquakes (Mw 5) in the past 30 years, and to present it spatially. It can be used to obtain the distribution areas of strong earthquakes with high frequency and activity level in recent years. By comparing the distribution of strong earthquakes in 2018 with that in 1989-2018, the distribution characteristics of global strong earthquakes in 2018 are obtained. The original data of strong earthquakes are from USGS, and the local density is calculated as frequency information. The magnitudes of all earthquake cases are interpolated globally, and then the frequency and magnitude are multiplied as the activity level of strong earthquakes. The data set is in TIff format with a spatial resolution of about 80 km. The data set can provide a reference for the analysis of strong earthquake activity level on the global scale, and is helpful for the analysis of global earthquake risk and the construction of earthquake prevention and disaster reduction system.
Chen Jin, Tang Hong, WU Jianjun, ZHOU Hongmin
The Tibetan Plateau has strong seismic activity, which is driven by the subduction and collision of the Indian plate between the Eurasian plate and the deformation of the plateau. There are 2854 earthquakes with Magnitude 4.7 or larger have occurred in Plateau region (north latitude 20-40 degrees and east longitude 70-105 degrees) since 1970. Among them, 3 earthquakes with Magnitude 8 or larger, 33 earthquakes with Magnitude 7.0-7.9， 192 earthquakes with Magnitude 6.0-6.9 and 1152 earthquakes with Magnitude 5.0-5.9 have occurred. Earthquakes occurred mainly along the faults in and around the Plateau.
WANG Ji
The Pan-Third Polar region has strong seismic activity, which is driven by the subduction and collision of the Indian plate, the Arab plate and the Eurasian plate. 18806 earthquakes with Magnitude 5 or larger have occurred in Pan-Third Polar region (north latitude 0-56 degrees and east longitude 43-139 degrees) since 1960. Among them, 4 earthquakes with Magnitude 8 or larger, 187 earthquakes with Magnitude 7.0-7.9， 1625 earthquakes with Magnitude 6.0-6.9 and 16990 earthquakes with Magnitude 5.0-5.9 have occurred. Earthquakes occurred mainly in the foothills of the India-Myanmar Mountains, the Himalaya Mountains, the Sulaiman Mountains, where the India Plate collided with the Eurasian plate, and the Zagros Mountains where the Arab plate collided with the Eurasian plate.
WANG Ji
The Tibetan Plateau region has strong seismic activity, which is driven by the subduction collision between the Indian plate and the Eurasian plate and the internal deformation of the plateau. A total of 5030 earthquakes of magnitude M≥5.0 have occurred on the Tibetan Plateau and surrounding areas (20-40°N, 70-105°E) . Historical records since the present ( December 2021), including 20 earthquakes of magnitude M≥8, 154 earthquakes of magnitude M=7.0-7.9, 913 earthquakes of magnitude M=6.0-6.9, and 3943 earthquakes of magnitude M=5.0-5.9. The earthquakes occurred mainly along the large faults zones around and within the Tibetan Plateau.
WANG Ji
We use waveform cross-correlation to analyze the recordings of eight earthquakes (2009-2018) beneath the Indian Ocean at stations from the Chinese Digital Seismic Network. We obtain 929 high quality residual traveltime differences between the phases ScS and S (Differential traveltimes.dat). We interpret variations of δt up to 10 seconds as due to horizontal shear-velocity variations in D” beneath northern India, Nepal, and southwestern China. The shear velocity can vary by as much as 7% over distances shorter than 300 km. Our observations provide additional observational evidence that compositional heterogeneity and possibly melt contribute to the seismic structure of the lower mantle characterized by long-term subduction and mantle downwelling.
LI Guohui, BAI Ling
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