The Sagaing Fault is a major tectonic structure between the Indian Plate and Sunda Plate. The fault measures 1200 km along north-south and cuts through the centre of Myanmar. Many urban areas lie along the fault. As a...The Sagaing Fault is a major tectonic structure between the Indian Plate and Sunda Plate. The fault measures 1200 km along north-south and cuts through the centre of Myanmar. Many urban areas lie along the fault. As a result, Myanmar has established a continuous Global Positioning System （cGPS） network across the Sagaing Fault since 2011. The cGPS network consists of eight cGPS stations that form two transects across the fault. The data analysis covers a period of four years from 2011 to 2014. GAMIT, GLOBK, and TRACK software suite packages are used for GPS data processing and analysis. This study consists of two main objectives. The first objective is to analyse the Myanmar cGPS network ob- servations in order to measure the moving rate and direction of movement for each cGPS station using GAMIT/GLOBK software packages. The second objective is to investigate the co-seismic moving rate associated with the earthquake event using TRACK kinematic positioning program. The analysis results indicate that the east side of the Sagaing Fault moves southeastward at the average rate of approximately 32-40 mm/a, whereas the west side of the fault moves northeastward at the rate of about 31-35 mm/a. For co-seismic analysis, two cGPS stations are analysed in connection with the 2012 M6.8 Thabeikkyin earthquake. These stations are located 50-60 km away from the epicentre. The GPS data analysis clearly showed that the station at the east side of the Sagaing Fault immediately moved south by 15.0 cm, whereas the station at the west side of the fault moved north by 3.0 cm. In conclusion, this study demonstrates that the Sagaing Fault＇s tectonic activities can be monitored by cGPS observations using geodetic processing techniques. We believe that such investigation brings contribution to better understand of the tectonic activities in Myanmar and South East Asia.展开更多
The active Sagaing fault in Myanmar defines the boundary between the Indian Plate and the Eurasian Plate and causes seismic damage in the major cities of Myanmar. Small bodies of serpentinite occur along the fault. We...The active Sagaing fault in Myanmar defines the boundary between the Indian Plate and the Eurasian Plate and causes seismic damage in the major cities of Myanmar. Small bodies of serpentinite occur along the fault. We for the first time investigated the highly sheared serpentinite bodies in the Sheinmagar area and Yega Inn area along the Sagaing fault. Extensively sheared/brecciated serpentinites and related rocks, such as talc and/or chlorite-bearing rocks contains small rock fragments of serpentinites. Serpentine texture and mineral chemistry indicate that the protolith of these serpentinites were mainly harzburgite with minor amounts of dunite, some of which are cut by gabbroic veins. No shape-preferred orientation of the antigorite is present, indicating that the serpentinization was occurred under relatively static conditions. Protolith and serpentine minerals are similar to those of the jadeitite-bearing serpentinites in the north of the Sagaing fault(the Jade Mine belt). Chemical variations of spinels in the studied area are within the compositional range of forearc peridotites and those in the mantle section of nearby ophiolites. After the formation of antigorite serpentinite under static conditions, these serpentinites were subsequently, but locally deformed, probably due to the activity of the Sagaing fault, resulting in the formation of serpentinite schist/brecciated rock. The presence of the less-deformed antigorite serpentinite in the sheared/brecciated zone indicates the strain localization mainly along the surrounding serpentine-talc(±chlorite) schistose rocks, which is probably formed by the reaction between serpentinite and country rocks. Further studies are needed to better understand whether the distribution of serpentinized peridotites cause variations in the activity of the Sagaing fault.展开更多
A devastating MW 7.7 earthquake struck near Mandalay,Myanmar,on March 28,2025,causing extensive damage and casualties across Myanmar and neighboring regions.The 2025 event occurred in a well-recognized seismic gap alo...A devastating MW 7.7 earthquake struck near Mandalay,Myanmar,on March 28,2025,causing extensive damage and casualties across Myanmar and neighboring regions.The 2025 event occurred in a well-recognized seismic gap along the Sagaing Fault.Here we focus on the mainshock rupture properties based on backprojection of teleseismic P waves and early aftershock locations,analysis of near-field seismic recordings for the mainshock initiation,and remotely triggered seismicity following the MW 7.7 mainshock.We find that the~500 km mainshock rupture can be revealed by both rapid back-projection of teleseismic P waves from multiple broadband arrays and early aftershock locations within about 3 h from the Thai Meteorological Department(TMD)catalog.The rupture speed went supershear in the southward propagation after the initial bilateral subshear ruptures,as expected for large strike-slip earthquakes of such sizes.Clear fault zone head waves that are reflected along a bimaterial fault interface are observed at the only near-fault station GE.NPW on the slower side about 2.6 km away from the Sagaing fault,consistent with the preferred direction of a supershear rupture propagating to the south.In addition,aftershocks from the regional TMD catalog appear to be located mostly to the east of the mainshock rupture.While we cannot completely rule out mis-locations from the one-sided station distribution,these off-fault seismicity could also be explained by reactivations of subsidiary faults within the Shan Plateau,or an eastward dipping of the mainshock rupture plane.Although no immediate foreshocks were found from several nearby stations,we identify one sub-event with magnitude~6 at the beginning of the mainshock with a slightly different focal mechanism about 20–30 km south of the hypocenter determined by the United States Geological Survey(USGS).The mainshock also occurred when the tidal stresses reached its maximum on the right-lateral strike-slip fault,likely indicating that the timing of the mainshock is modulated by the solid earth tides.We find a significant increase of seismic activity near the Thailand/Myanmar border,in multiple(geothermally active)regions of Yunnan province in Southwest China,as well as the Xingfengjian reservoir in the Guangdong province in South China.Because static stress changes from the mainshock are small but negative near the Thailand/Myanmar border,the occurrence of microseismicity in this and other regions can be mainly explained by remote triggering from dynamic stress changes of the mainshock rupture.Our analyses demonstrate the importance of rapid analysis on openly available seismic data and catalog to better understand the rupture properties and triggered seismicity following large earthquakes.展开更多
On 21st January 2025,Uster FiberQ automated raw material management generated more than 2,000 laydowns in a year for Saga r,one of India's leading spinners.The results delivered consistent yarn quality and optimiz...On 21st January 2025,Uster FiberQ automated raw material management generated more than 2,000 laydowns in a year for Saga r,one of India's leading spinners.The results delivered consistent yarn quality and optimized process efficiencygiving a payback period of three months.Sagar is convinced of the benefits from the full FiberQ package,taking advantage of the new annual subscription format.展开更多
基金supported by Earth Observatory of Singapore(EOS)Myanmar Earthquake CommitteeDepartment of Meteorology and Hydrology(Myanmar)
文摘The Sagaing Fault is a major tectonic structure between the Indian Plate and Sunda Plate. The fault measures 1200 km along north-south and cuts through the centre of Myanmar. Many urban areas lie along the fault. As a result, Myanmar has established a continuous Global Positioning System （cGPS） network across the Sagaing Fault since 2011. The cGPS network consists of eight cGPS stations that form two transects across the fault. The data analysis covers a period of four years from 2011 to 2014. GAMIT, GLOBK, and TRACK software suite packages are used for GPS data processing and analysis. This study consists of two main objectives. The first objective is to analyse the Myanmar cGPS network ob- servations in order to measure the moving rate and direction of movement for each cGPS station using GAMIT/GLOBK software packages. The second objective is to investigate the co-seismic moving rate associated with the earthquake event using TRACK kinematic positioning program. The analysis results indicate that the east side of the Sagaing Fault moves southeastward at the average rate of approximately 32-40 mm/a, whereas the west side of the fault moves northeastward at the rate of about 31-35 mm/a. For co-seismic analysis, two cGPS stations are analysed in connection with the 2012 M6.8 Thabeikkyin earthquake. These stations are located 50-60 km away from the epicentre. The GPS data analysis clearly showed that the station at the east side of the Sagaing Fault immediately moved south by 15.0 cm, whereas the station at the west side of the fault moved north by 3.0 cm. In conclusion, this study demonstrates that the Sagaing Fault＇s tectonic activities can be monitored by cGPS observations using geodetic processing techniques. We believe that such investigation brings contribution to better understand of the tectonic activities in Myanmar and South East Asia.
基金supported by a Grants-in-Aid for Scientific Research from the Ministry of Education Culture, Sports, Science and Technology of Japan, awarded to T.M. (Nos. 16H05741 and 19H01990)Sakura Science Plane 2018 of Japan Science and Technology Agency (JST)Kanazawa University SAKIGAKE 2018。
文摘The active Sagaing fault in Myanmar defines the boundary between the Indian Plate and the Eurasian Plate and causes seismic damage in the major cities of Myanmar. Small bodies of serpentinite occur along the fault. We for the first time investigated the highly sheared serpentinite bodies in the Sheinmagar area and Yega Inn area along the Sagaing fault. Extensively sheared/brecciated serpentinites and related rocks, such as talc and/or chlorite-bearing rocks contains small rock fragments of serpentinites. Serpentine texture and mineral chemistry indicate that the protolith of these serpentinites were mainly harzburgite with minor amounts of dunite, some of which are cut by gabbroic veins. No shape-preferred orientation of the antigorite is present, indicating that the serpentinization was occurred under relatively static conditions. Protolith and serpentine minerals are similar to those of the jadeitite-bearing serpentinites in the north of the Sagaing fault(the Jade Mine belt). Chemical variations of spinels in the studied area are within the compositional range of forearc peridotites and those in the mantle section of nearby ophiolites. After the formation of antigorite serpentinite under static conditions, these serpentinites were subsequently, but locally deformed, probably due to the activity of the Sagaing fault, resulting in the formation of serpentinite schist/brecciated rock. The presence of the less-deformed antigorite serpentinite in the sheared/brecciated zone indicates the strain localization mainly along the surrounding serpentine-talc(±chlorite) schistose rocks, which is probably formed by the reaction between serpentinite and country rocks. Further studies are needed to better understand whether the distribution of serpentinized peridotites cause variations in the activity of the Sagaing fault.
基金supported by National Science Foundation Grant RISE-2425889supported by Earthquake Prediction Open Fund,China Earthquake Administration(Grant No.XH25006D)supported by the International Partnership Program of Chinese Academy of Sciences(Grant No.164GJHZ2023006MI).
文摘A devastating MW 7.7 earthquake struck near Mandalay,Myanmar,on March 28,2025,causing extensive damage and casualties across Myanmar and neighboring regions.The 2025 event occurred in a well-recognized seismic gap along the Sagaing Fault.Here we focus on the mainshock rupture properties based on backprojection of teleseismic P waves and early aftershock locations,analysis of near-field seismic recordings for the mainshock initiation,and remotely triggered seismicity following the MW 7.7 mainshock.We find that the~500 km mainshock rupture can be revealed by both rapid back-projection of teleseismic P waves from multiple broadband arrays and early aftershock locations within about 3 h from the Thai Meteorological Department(TMD)catalog.The rupture speed went supershear in the southward propagation after the initial bilateral subshear ruptures,as expected for large strike-slip earthquakes of such sizes.Clear fault zone head waves that are reflected along a bimaterial fault interface are observed at the only near-fault station GE.NPW on the slower side about 2.6 km away from the Sagaing fault,consistent with the preferred direction of a supershear rupture propagating to the south.In addition,aftershocks from the regional TMD catalog appear to be located mostly to the east of the mainshock rupture.While we cannot completely rule out mis-locations from the one-sided station distribution,these off-fault seismicity could also be explained by reactivations of subsidiary faults within the Shan Plateau,or an eastward dipping of the mainshock rupture plane.Although no immediate foreshocks were found from several nearby stations,we identify one sub-event with magnitude~6 at the beginning of the mainshock with a slightly different focal mechanism about 20–30 km south of the hypocenter determined by the United States Geological Survey(USGS).The mainshock also occurred when the tidal stresses reached its maximum on the right-lateral strike-slip fault,likely indicating that the timing of the mainshock is modulated by the solid earth tides.We find a significant increase of seismic activity near the Thailand/Myanmar border,in multiple(geothermally active)regions of Yunnan province in Southwest China,as well as the Xingfengjian reservoir in the Guangdong province in South China.Because static stress changes from the mainshock are small but negative near the Thailand/Myanmar border,the occurrence of microseismicity in this and other regions can be mainly explained by remote triggering from dynamic stress changes of the mainshock rupture.Our analyses demonstrate the importance of rapid analysis on openly available seismic data and catalog to better understand the rupture properties and triggered seismicity following large earthquakes.
文摘On 21st January 2025,Uster FiberQ automated raw material management generated more than 2,000 laydowns in a year for Saga r,one of India's leading spinners.The results delivered consistent yarn quality and optimized process efficiencygiving a payback period of three months.Sagar is convinced of the benefits from the full FiberQ package,taking advantage of the new annual subscription format.
