Abstract We present a new whole mantle P wave tomographic model GAP_P4. used two data groups; short‐period of more than 10 million picked‐up onset times and long‐period 20 thousand differential travel measured by waveform cross correlation. Finite frequency kernels were calculated at the corresponding bands for both long‐ data. With respect to an earlier GAP_P2, we find important improvements especially in transition zone uppermost lower beneath South China Sea southern Philippine owing...

A total of 361 SKS and five local S wave splitting measurements obtained at global regional seismic network stations in NE China Mongolia are used to infer the characteristics mantle fabrics beneath northeast Asia. Fast polarization directions most western part study area found be consistent with strike geological features. The dominant fast eastern part, which tomography receiver function studies revealed a deflected slab transition zone (MTZ), about 100° from north, almost exactly same as...

This paper uses data from the Capital Area Seismograph Network in North China (NC), currently largest regional seismograph network to investigate compressional stress orientations polarizations of faster shear waves (PFS), a parameter wave velocity anisotropy. Data are restricted earthquakes deeper than 5 km reduce influence heterogeneous uppermost few kilometres crust. The results show that direction is ENE-WSW nearly EW NC, which agrees with seismic mechanisms and drilling GPS data....

We analysed a large amount of teleseismic receiver function data recorded by 172 broadband stations in the NE Tibetan plateau and its surrounding areas to investigate crustal velocity anisotropy structure beneath margin. first applied modified H–κ stacking technique measure thickness average Vp/Vs ratio, then employed joint inversion scheme azimuthal crust each station. The observed ratio exhibit variations across study area, varying from 32 75.6 km 1.601 1.864, respectively. also found...

Theory and observations suggest that seismic shear wave splitting, caused by fluid-saturated stress-aligned microcracks, directly monitors low-level deformation before fracturing, faulting earthquakes occur. In the past, it had been assumed accumulation of stress continued until was released at time earthquake. However, new data reappraisal existing sets now suggests begins to relax cracks close from tens minutes months earthquake actually occurs, with logarithm duration relaxation...

Abstract Lithospheric shear wave velocity beneath the southeastern margin of Tibetan Plateau is obtained from Rayleigh tomography using earthquake data recorded by temporary ChinArray and permanent China Digital Seismic Array. Fundamental mode phase velocities at periods 20–100 s are determined used to construct 3‐D model. Low‐velocity anomalies appear along or close major faults in middle crust become a broad zone lower crust, suggesting block extrusion shallow diffuse deformation both...

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An isolated swarm of small earthquakes occurred in 1992, near Dongfang on Hainan Island, southern China. The Institute Geophysics, State Seismological Bureau China, monitored the with five DCS-302 digital accelerometers for three months from 1992 June 1. 18 earthquakes, magnitudes ML ranging 1.8 to 3.6, were well located by stations, and shear-wave splitting varying azimuthally was analysed 27 seismic records these events. mean polarization azimuth faster shear wave WNW. Time delays between...

Measurements of time-delays in seismic shear-wave splitting above small earthquakes typically display a scatter often as much ±80 per cent about the mean. Changes average time-delay appear to be related changes stress, but applications this potentially powerful tool have been handicapped by previously inexplicable earthquakes. In contrast, measurements controlled-source exploration seismics are well controlled and little scatter. Previous estimates possible causes cannot produce sufficient...

SUMMARY Resolving the detail of crustal deformation seismically and technically active Sichuan-Yunnan block located in southeast margin Tibetan Plateau is crucial for understanding lateral extrusion Plateau. Using seismic data from two regional seismograph stations China Earthquake Networks Center twenty recently deployed broad-band temporary MCD Array (Middle ChuanDian array), we constrained thickness anisotropy at west boundary block, near east Himalayan syntaxis by receiver function...

Research Article| May 01, 2008 Stress-forecasting (not predicting) earthquakes: A paradigm shift? Stuart Crampin; Crampin * 1School of GeoSciences, University Edinburgh, Edinburgh EH9 3JW, UK *E-mail: scrampin@ed.ac.uk Search for other works by this author on: GSW Google Scholar Yuan Gao; Gao 2Institute Earthquake Science, China Administration, 100036 Beijing, Sheila Peacock 3AWE Blacknest, Brimpton, Reading RG7 4RS, Author and Article Information Publisher: Geological Society America...

We analyzed 360 permanent and campaign GPS data from 1999 to 2017 in the southern Sichuan-Yunan block, obtained crustal horizontal deformation this region. Then, we derived strain rate using a multi-scale spherical wavelet method. Results reveal complex pattern of tectonic movement Sichuan-Yunnan block. Compared stable Eurasian plate, maximum block is approximately 22 mm/a. The Xiaojiang fault shows significantly lower deformation—a left-lateral strike-slip 9.5 Honghe clearly segmental north...

Abstract Indo‐Asian continental collision has contributed to the growth of Tibetan Plateau, which is one most prominent uplifts worldwide since Cenozoic. The crustal and upper‐mantle structures are key factors in understanding evolutionary process as well lateral plateau. We present a new 3‐D seismic model beneath Plateau its surrounding areas, uses large‐scale dense array from iterative finite‐frequency tomography. tomographic images show obvious east‐west geometrical change northward...

SUMMARY The distribution of block boundary faults, both horizontally and vertically, has significant implications for crustal movements structural variations. In the SE margin Tibetan Plateau, south part Sichuan–Yunnan is surrounded by first-order boundaries Honghe faults (HHF) trending NW–SE Xiaojiang (XJF) N–S. Crustal anisotropy provides valuable insights into ongoing deformation evolution. This study investigates upper-crustal at 26 stations, using local seismic waveforms from temporary...

Propose To review published Physical Activity (PA) on the Mental Health of Children and Adolescents aged 5 to 18 years during COVID-19 pandemic-induced school closures. Methods From database creation April 2022, 10 databases are retrieved, with 4427 records filtered, 14 included in this research. The research takes Agency for Healthcare Research Quality (AHRQ) evaluation standards. Results thesis selects studies from 6 countries, involving 400009 children adolescents. These happened lockdown...