A robust estimation of the earthquake location, seismic moment, and fault geometry is essential for objective seismic hazard assessment. Seismic events in a remote location, specifically in the absence of seismic and GNSS networks, can be investigated effectively using the InSAR-based technique. This study adopts the Differential Interferometric SAR (DInSAR) technique to quantify the co-seismic surface displacement caused by the June 21, 2022, Khōst MW6, Afghanistan earthquake that occurred along the western plate boundary between the Indian and Eurasian plate. The interferograms show that the maximum surface deformation occurred on the northwest and southwest of the fault line. From coherence, the Line of Sight (LOS)displacement, and the co-seismic surface displacement analysis, it has been observed that surface deformation was most pronounced in the southwest region of the fault line, and the surface has moved to the opposite direction along the fault line, which indicates a sinistral slightly oblique strike-slip movement. This InSAR-based observation appears consistent with the seismic waveforms derived from co-seismic surface displacements. Further, it has been argued that the slip deficit accumulated during the period of the last about 48 years along the frontal region of the northward extension of the Suleiman range and associated fault zone is qualitatively estimated at about 1.5 m, which is consistent with the seismic waveforms derived finite slip model.
{"title":"Co-seismic surface displacement of the June 21, 2022 Khōst MW6, Afghanistan earthquake from InSAR observations","authors":"Prohelika Dalal, Batakrushna Senapati, Bhaskar Kundu","doi":"10.1016/j.geog.2023.08.003","DOIUrl":"https://doi.org/10.1016/j.geog.2023.08.003","url":null,"abstract":"A robust estimation of the earthquake location, seismic moment, and fault geometry is essential for objective seismic hazard assessment. Seismic events in a remote location, specifically in the absence of seismic and GNSS networks, can be investigated effectively using the InSAR-based technique. This study adopts the Differential Interferometric SAR (DInSAR) technique to quantify the co-seismic surface displacement caused by the June 21, 2022, Khōst MW6, Afghanistan earthquake that occurred along the western plate boundary between the Indian and Eurasian plate. The interferograms show that the maximum surface deformation occurred on the northwest and southwest of the fault line. From coherence, the Line of Sight (LOS)displacement, and the co-seismic surface displacement analysis, it has been observed that surface deformation was most pronounced in the southwest region of the fault line, and the surface has moved to the opposite direction along the fault line, which indicates a sinistral slightly oblique strike-slip movement. This InSAR-based observation appears consistent with the seismic waveforms derived from co-seismic surface displacements. Further, it has been argued that the slip deficit accumulated during the period of the last about 48 years along the frontal region of the northward extension of the Suleiman range and associated fault zone is qualitatively estimated at about 1.5 m, which is consistent with the seismic waveforms derived finite slip model.","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"45 5-6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135615029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1016/j.geog.2023.02.002
Jiangtao Qiu , Lingyun Ji , Liangyu Zhu , Chuanjin Liu , Jinshuo Wang
On June 22, 2022, the Mw6.2 earthquake in southeastern Afghanistan caused a severe disaster. We used the Sentinel-1A ascending and descending track images of the European Space Agency and interferometric synthetic aperture radar (InSAR) to obtain the coseismic surface deformation field of the earthquake, which showed that the earthquake caused complex ruptures of multiple faults and various types. Using the dislocation model of the elastic half-space, we determined the focal parameters and slip distribution on the fault plane of this event. The results reveal that: (1) the seismogenic fault of this event is an unknown fault on the northeastern edge of the Katawaz microblock; (2) The slip on the fault plane is mainly in the range of 0–8 km along the dip, with maximum slips about 2 m at a depth of 2 km, which projected on the surface is 69.44°E, 32.96°N. This event suggests that, similar to the Chaman, Ghazaband and other large faults, the faults inside the microblock also play an important role in adjusting for the collision stress between India and Europe.
{"title":"The June 2022 Khost earthquake in southeastern Afghanistan: A complicated shallow slip event revealed with InSAR","authors":"Jiangtao Qiu , Lingyun Ji , Liangyu Zhu , Chuanjin Liu , Jinshuo Wang","doi":"10.1016/j.geog.2023.02.002","DOIUrl":"10.1016/j.geog.2023.02.002","url":null,"abstract":"<div><p>On June 22, 2022, the <em>M</em>w6.2 earthquake in southeastern Afghanistan caused a severe disaster. We used the Sentinel-1A ascending and descending track images of the European Space Agency and interferometric synthetic aperture radar (InSAR) to obtain the coseismic surface deformation field of the earthquake, which showed that the earthquake caused complex ruptures of multiple faults and various types. Using the dislocation model of the elastic half-space, we determined the focal parameters and slip distribution on the fault plane of this event. The results reveal that: (1) the seismogenic fault of this event is an unknown fault on the northeastern edge of the Katawaz microblock; (2) The slip on the fault plane is mainly in the range of 0–8 km along the dip, with maximum slips about 2 m at a depth of 2 km, which projected on the surface is 69.44°E, 32.96°N. This event suggests that, similar to the Chaman, Ghazaband and other large faults, the faults inside the microblock also play an important role in adjusting for the collision stress between India and Europe.</p></div>","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"14 6","pages":"Pages 559-565"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1674984723000198/pdfft?md5=7e0691502e1d433d3dec83531960ba7e&pid=1-s2.0-S1674984723000198-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46719615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The construction of dams for intercepting and storing water has altered surface water distributions, land-sea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir properties through the land surface and hydrological models can lead to water storage simulation and extraction errors. This impact is particularly evident in many artificial reservoirs in China. The study aims to comprehensively assess the spatiotemporal distribution and trends of water storage in medium and large reservoirs (MLRs) in inland China during 1950–2016, and to investigate the gravity, displacement, and strain effects induced by the reservoir mass concentration using the load elasticity theory. In addition, the impoundment contributions of MLRs to the relative sea level changes were assessed using a sea-level equation. The results show impoundment increases in the MLRs during 1950–2016, particularly in the Yangtze River (Changjiang) and southern basins, causing significant elastic load effects in the surrounding areas of the reservoirs and increasing the relative sea level in China's offshore. However, long-term groundwater estimation trends are overestimated and underestimated in the Yangtze River and southwestern basins, respectively, due to the neglect of the MLRs impacts or the uncertainty of the hydrological model's output (e.g., soil moisture, etc.). The construction of MLRs may reduce the water mass input from land to the ocean, thus slowing global sea level rise. The results of the impact of human activities on the regional water cycle provide important references and data support for improving the integration of hydrological models, evaluating Earth's viscoelastic responses under long-term reservoir storage, enhancing in-situ and satellite geodetic measurements, and identifying the main factors driving sea level changes.
{"title":"Impacts of artificial dams on terrestrial water storage changes and the Earth's elastic load response during 1950–2016: A case study of medium and large reservoirs in inland China","authors":"Linsong Wang, Mingtao Zhu, Yulong Zhong, Jianwei Sun, Zhenran Peng","doi":"10.1016/j.geog.2023.07.009","DOIUrl":"https://doi.org/10.1016/j.geog.2023.07.009","url":null,"abstract":"The construction of dams for intercepting and storing water has altered surface water distributions, land-sea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir properties through the land surface and hydrological models can lead to water storage simulation and extraction errors. This impact is particularly evident in many artificial reservoirs in China. The study aims to comprehensively assess the spatiotemporal distribution and trends of water storage in medium and large reservoirs (MLRs) in inland China during 1950–2016, and to investigate the gravity, displacement, and strain effects induced by the reservoir mass concentration using the load elasticity theory. In addition, the impoundment contributions of MLRs to the relative sea level changes were assessed using a sea-level equation. The results show impoundment increases in the MLRs during 1950–2016, particularly in the Yangtze River (Changjiang) and southern basins, causing significant elastic load effects in the surrounding areas of the reservoirs and increasing the relative sea level in China's offshore. However, long-term groundwater estimation trends are overestimated and underestimated in the Yangtze River and southwestern basins, respectively, due to the neglect of the MLRs impacts or the uncertainty of the hydrological model's output (e.g., soil moisture, etc.). The construction of MLRs may reduce the water mass input from land to the ocean, thus slowing global sea level rise. The results of the impact of human activities on the regional water cycle provide important references and data support for improving the integration of hydrological models, evaluating Earth's viscoelastic responses under long-term reservoir storage, enhancing in-situ and satellite geodetic measurements, and identifying the main factors driving sea level changes.","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"39 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1016/j.geog.2023.06.001
Jian Xie, Tianwei Qiu, Cui Zhou, Dongfang Lin, Sichun Long
Weighted total least squares (WTLS) have been regarded as the standard tool for the errors-in-variables (EIV) model in which all the elements in the observation vector and the coefficient matrix are contaminated with random errors. However, in many geodetic applications, some elements are error-free and some random observations appear repeatedly in different positions in the augmented coefficient matrix. It is called the linear structured EIV (LSEIV) model. Two kinds of methods are proposed for the LSEIV model from functional and stochastic modifications. On the one hand, the functional part of the LSEIV model is modified into the errors-in-observations (EIO) model. On the other hand, the stochastic model is modified by applying the Moore-Penrose inverse of the cofactor matrix. The algorithms are derived through the Lagrange multipliers method and linear approximation. The estimation principles and iterative formula of the parameters are proven to be consistent. The first-order approximate variance-covariance matrix (VCM) of the parameters is also derived. A numerical example is given to compare the performances of our proposed three algorithms with the STLS approach. Afterwards, the least squares (LS), total least squares (TLS) and linear structured weighted total least squares (LSWTLS) solutions are compared and the accuracy evaluation formula is proven to be feasible and effective. Finally, the LSWTLS is applied to the field of deformation analysis, which yields a better result than the traditional LS and TLS estimations.
{"title":"Algorithms and statistical analysis for linear structured weighted total least squares problem","authors":"Jian Xie, Tianwei Qiu, Cui Zhou, Dongfang Lin, Sichun Long","doi":"10.1016/j.geog.2023.06.001","DOIUrl":"https://doi.org/10.1016/j.geog.2023.06.001","url":null,"abstract":"Weighted total least squares (WTLS) have been regarded as the standard tool for the errors-in-variables (EIV) model in which all the elements in the observation vector and the coefficient matrix are contaminated with random errors. However, in many geodetic applications, some elements are error-free and some random observations appear repeatedly in different positions in the augmented coefficient matrix. It is called the linear structured EIV (LSEIV) model. Two kinds of methods are proposed for the LSEIV model from functional and stochastic modifications. On the one hand, the functional part of the LSEIV model is modified into the errors-in-observations (EIO) model. On the other hand, the stochastic model is modified by applying the Moore-Penrose inverse of the cofactor matrix. The algorithms are derived through the Lagrange multipliers method and linear approximation. The estimation principles and iterative formula of the parameters are proven to be consistent. The first-order approximate variance-covariance matrix (VCM) of the parameters is also derived. A numerical example is given to compare the performances of our proposed three algorithms with the STLS approach. Afterwards, the least squares (LS), total least squares (TLS) and linear structured weighted total least squares (LSWTLS) solutions are compared and the accuracy evaluation formula is proven to be feasible and effective. Finally, the LSWTLS is applied to the field of deformation analysis, which yields a better result than the traditional LS and TLS estimations.","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134935901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The deformation monitoring of long-span railway bridges is significant to ensure the safety of human life and property. The interferometric synthetic aperture radar (InSAR) technology has the advantage of high accuracy in bridge deformation monitoring. This study monitored the deformation of the Ganjiang Super Bridge based on the small baseline subsets (SBAS) InSAR technology and Sentinel-1A data. We analyzed the deformation results combined with bridge structure, temperature, and riverbed sediment scouring. The results are as follows: (1) The Ganjiang Super Bridge area is stable overall, with deformation rates ranging from −15.6 mm/yr to 10.7 mm/yr (2) The settlement of the Ganjiang Super Bridge deck gradually increases from the bridge tower toward the main span, which conforms to the typical deformation pattern of a cable-stayed bridge. (3) The sediment scouring from the riverbed cause the serious settlement on the bridge's east side compared with that on the west side. (4) The bridge deformation negatively correlates with temperature, with a faster settlement at a higher temperature and a slow rebound trend at a lower temperature. The study findings can provide scientific data support for the health monitoring of long-span railway bridges.
{"title":"Deformation monitoring of long-span railway bridges based on SBAS-InSAR technology","authors":"Lv Zhou, Xinyi Li, Yuanjin Pan, Jun Ma, Cheng Wang, Anping Shi, Yukai Chen","doi":"10.1016/j.geog.2023.07.005","DOIUrl":"https://doi.org/10.1016/j.geog.2023.07.005","url":null,"abstract":"The deformation monitoring of long-span railway bridges is significant to ensure the safety of human life and property. The interferometric synthetic aperture radar (InSAR) technology has the advantage of high accuracy in bridge deformation monitoring. This study monitored the deformation of the Ganjiang Super Bridge based on the small baseline subsets (SBAS) InSAR technology and Sentinel-1A data. We analyzed the deformation results combined with bridge structure, temperature, and riverbed sediment scouring. The results are as follows: (1) The Ganjiang Super Bridge area is stable overall, with deformation rates ranging from −15.6 mm/yr to 10.7 mm/yr (2) The settlement of the Ganjiang Super Bridge deck gradually increases from the bridge tower toward the main span, which conforms to the typical deformation pattern of a cable-stayed bridge. (3) The sediment scouring from the riverbed cause the serious settlement on the bridge's east side compared with that on the west side. (4) The bridge deformation negatively correlates with temperature, with a faster settlement at a higher temperature and a slow rebound trend at a lower temperature. The study findings can provide scientific data support for the health monitoring of long-span railway bridges.","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135407613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1016/j.geog.2023.07.006
Juan A. García-Armenteros
This paper analyzed GPS data from the Topo-Iberia network spanning almost 12 years (2008–2020). The data quality information for all 26 Topo-Iberia stations is provided for the first time, complementing the Spanish Geological Survey's storage work. Data analyses based on quality indicators obtained using TEQC have been carried out. The guidelines and data quality information from the IGS stations have been considered as the quality references, with the stations ALJI, EPCU, and TIOU standing out as the worst stations, while on the contrary, FUEN, PALM, PILA, and TRIA meet the quality requirements to become an IGS station. The relationship between the GPS data quality and their GAMIT- and GipsyX-derived postfit ionosphere-free phase residuals has also been investigated, and the results reveal an inversely proportional relationship. It has been found that the stations showing an increase in elevation of the horizon line, also show an increase in cycle slips and multipath, are among the poorest quality stations, and among those with the highest postfit RMS of phase residuals. Moreover, the evolution of the vegetation around the antenna should be considered as it could cause a progressive loss of quality, which is not complying with the IGS standards. The quality assessment shows that the Topo-Iberia stations are appropriate for geodetic purposes, but permanent monitoring would be necessary to avoid the least possible loss of data and quality. In addition, a method to characterize the GNSS data quality is proposed.
{"title":"Quality assessment of the Topo-Iberia CGPS stations and data quality's effects on postfit ionosphere-free phase residuals","authors":"Juan A. García-Armenteros","doi":"10.1016/j.geog.2023.07.006","DOIUrl":"https://doi.org/10.1016/j.geog.2023.07.006","url":null,"abstract":"This paper analyzed GPS data from the Topo-Iberia network spanning almost 12 years (2008–2020). The data quality information for all 26 Topo-Iberia stations is provided for the first time, complementing the Spanish Geological Survey's storage work. Data analyses based on quality indicators obtained using TEQC have been carried out. The guidelines and data quality information from the IGS stations have been considered as the quality references, with the stations ALJI, EPCU, and TIOU standing out as the worst stations, while on the contrary, FUEN, PALM, PILA, and TRIA meet the quality requirements to become an IGS station. The relationship between the GPS data quality and their GAMIT- and GipsyX-derived postfit ionosphere-free phase residuals has also been investigated, and the results reveal an inversely proportional relationship. It has been found that the stations showing an increase in elevation of the horizon line, also show an increase in cycle slips and multipath, are among the poorest quality stations, and among those with the highest postfit RMS of phase residuals. Moreover, the evolution of the vegetation around the antenna should be considered as it could cause a progressive loss of quality, which is not complying with the IGS standards. The quality assessment shows that the Topo-Iberia stations are appropriate for geodetic purposes, but permanent monitoring would be necessary to avoid the least possible loss of data and quality. In addition, a method to characterize the GNSS data quality is proposed.","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135406727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1016/j.geog.2023.05.007
Mohamed Eleiche, Ahmed Mansi
The conversion of the cartesian coordinates of a point to its geodetic equivalent coordinates in reference to the geodetic ellipsoid is one of the main challenges in geodesy. The ellipse equation in the meridian plane significantly influences the value of the geodetic coordinates. This research analyzes this influence and how it can contribute to their solutions. The study investigates the mathematical relation between them and presents an exact formula relating to the geodetic height and the ellipse equation. In addition, a heuristic formula for the relation between the geodetic height and the ellipse equation is proposed, which is independent of the geodetic latitude and has a relative accuracy better than 99.9 %. The calculation is stable, and the cost is low.
{"title":"Exact and heuristic formulae to compute the geodetic height from the ellipse equation","authors":"Mohamed Eleiche, Ahmed Mansi","doi":"10.1016/j.geog.2023.05.007","DOIUrl":"https://doi.org/10.1016/j.geog.2023.05.007","url":null,"abstract":"The conversion of the cartesian coordinates of a point to its geodetic equivalent coordinates in reference to the geodetic ellipsoid is one of the main challenges in geodesy. The ellipse equation in the meridian plane significantly influences the value of the geodetic coordinates. This research analyzes this influence and how it can contribute to their solutions. The study investigates the mathematical relation between them and presents an exact formula relating to the geodetic height and the ellipse equation. In addition, a heuristic formula for the relation between the geodetic height and the ellipse equation is proposed, which is independent of the geodetic latitude and has a relative accuracy better than 99.9 %. The calculation is stable, and the cost is low.","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135849437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Active tectonics in an area includes ongoing or recent geologic events. This paper investigates the tectonic influence on the subsidence, uplift and tilt of western Saurashtra through morphotectonic analysis of ten watersheds along with characteristics of relief and drainage orientation. Watersheds 7–9 to the north (N) are tectonically active, which can be linked with the North Kathiawar Fault System (NKFS) and followed by watersheds 6, 10, 1, 4 and 5. Stream-length gradient index and sinuosity index indicate the effect of tectonic events along the master streams in watersheds 6–9. Higher R2 values of the linear curve fit for watershed 7 indicate its master stream is much more tectonically active than the others. The R2 curve fitting model and earthquake magnitude/depth analysis confirm the region to be active. The reactivation of the NKFS most likely led to the vertical movement of western Saurashtra.
{"title":"Geomorphic signatures and active tectonics in western Saurashtra, Gujarat, India","authors":"Bikramaditya Mondal , Mery Biswas , Soumyajit Mukherjee , Mohamedharoon A. Shaikh","doi":"10.1016/j.geog.2023.08.001","DOIUrl":"10.1016/j.geog.2023.08.001","url":null,"abstract":"<div><p>Active tectonics in an area includes ongoing or recent geologic events. This paper investigates the tectonic influence on the subsidence, uplift and tilt of western Saurashtra through morphotectonic analysis of ten watersheds along with characteristics of relief and drainage orientation. Watersheds 7–9 to the north (N) are tectonically active, which can be linked with the North Kathiawar Fault System (NKFS) and followed by watersheds 6, 10, 1, 4 and 5. Stream-length gradient index and sinuosity index indicate the effect of tectonic events along the master streams in watersheds 6–9. Higher <em>R</em><sup>2</sup> values of the linear curve fit for watershed 7 indicate its master stream is much more tectonically active than the others. The <em>R</em><sup>2</sup> curve fitting model and earthquake magnitude/depth analysis confirm the region to be active. The reactivation of the NKFS most likely led to the vertical movement of western Saurashtra.</p></div>","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"15 1","pages":"Pages 82-99"},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1674984723000587/pdfft?md5=78bde20fdd30c9d8bc5b2b8ac40c6da4&pid=1-s2.0-S1674984723000587-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47077932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.1016/j.geog.2023.08.002
Yu Li, Yuebing Wang, Lijiang Zhao, Hongbo Shi, Pingping Wang
Rapid acquisition of the kinetics deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue, disaster assessment, and future seismic risk research. The advancement of GNSS observation and data processing makes it play an important role in this field, especially the high-frequency GNSS. We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the MS7.4 Maduo earthquake epicenter. The kinetics deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained. The results show that: 1) Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter. Coseismic response deformation on the east and west sides shows bilateral asymmetry, which markedly differs from the symmetry presented by surface rupture. 2) The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area, although the former is generally slightly smaller than the latter. 3) There may exist obstacles on the eastern side of the seismogenic fault. The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault (KPJF) and Maqin-Maqu segment, resulting in higher seismic risk in the future.
{"title":"Kinetics deformation characteristics and intensity assessment of the 2021 Maduo M7.4 earthquake in Qinghai revealed by high-frequency GNSS","authors":"Yu Li, Yuebing Wang, Lijiang Zhao, Hongbo Shi, Pingping Wang","doi":"10.1016/j.geog.2023.08.002","DOIUrl":"https://doi.org/10.1016/j.geog.2023.08.002","url":null,"abstract":"Rapid acquisition of the kinetics deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue, disaster assessment, and future seismic risk research. The advancement of GNSS observation and data processing makes it play an important role in this field, especially the high-frequency GNSS. We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the MS7.4 Maduo earthquake epicenter. The kinetics deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained. The results show that: 1) Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter. Coseismic response deformation on the east and west sides shows bilateral asymmetry, which markedly differs from the symmetry presented by surface rupture. 2) The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area, although the former is generally slightly smaller than the latter. 3) There may exist obstacles on the eastern side of the seismogenic fault. The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault (KPJF) and Maqin-Maqu segment, resulting in higher seismic risk in the future.","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135588814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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