ChinArray is a dense portable broadband seismic network to cover the entire continental China, and the Phase I is deployed along the north-south seismic belt in southwest China. In this study, we analyze seismic data ...ChinArray is a dense portable broadband seismic network to cover the entire continental China, and the Phase I is deployed along the north-south seismic belt in southwest China. In this study, we analyze seismic data recorded on the ChinArray following the February 15, 2013 Chelyabinsk （Russia） meteor. This was the largest known object entering the Earth＇s atmosphere since the 1908 Tunguska meteor. The seismic energy radiated from this event was recorded by seismic stations worldwide including the dense ChinAn＇ay that are more than 4000 km away. The weak signal from the meteor event was con- taminated by a magnitude 5.8 Tonga earthquake occur- red ~ 20 min earlier. To test the feasibility of detecting the weak seismic signals from the meteor event, we compute vespagram and perform F-K analysis to the surface-wave data. We identify a seismic phase with back azimuth （BAZ） of 329.7° and slowness of 34.73 s/deg, corre- sponding to the surface wave from the Russian meteor event （BAZ ） 325.97°）. The surface magnitude （Ms） of the meteor event is 3.94 ±0.18. We also perform similar analysis on the data from the broadband array F-net in Japan, and find the BAZ of the surface waves to be 316.61%. With the different BAZs of ChinArray and F-net, we locate the Russian meteor event at 58.80°N, 58.72°E. The relatively large mislocation （-438 km as compared with 55.15°N. 61.41°E by others） may be a result of theweak signals at teleseismic distances.展开更多
The vertical-vertical noise cross-correlation functions(NCFs)between two seismic arrays,the Japan F-net and Chin Array phase Ⅱ,are calculated using continuous recordings during 2013-2016.After array interferometry to...The vertical-vertical noise cross-correlation functions(NCFs)between two seismic arrays,the Japan F-net and Chin Array phase Ⅱ,are calculated using continuous recordings during 2013-2016.After array interferometry to obtain bin stacked NCFs,clear body waves are retrieved at different period bands.Teleseismic direct P waves for distance 15-40 degrees are observed between short period 3-10 s while core reflected PcP/ScS waves are more obvious for longer period 30-60 s.The signal-to-noise-ratio(SNR)of the short period P waves reaches its highest point with bin widths around 20 km while SNRs of PcP and ScS increase slowly with bin width.All those body waves demonstrate clear directivity with strong signals traveling from the east.The time-lapse SNR variations for the PcP and ScS show correlation with the occurrence of major earthquakes,while the P-wave SNR demonstrates seasonal variations with additional contribution from major earthquakes.The present results suggest teleseismic body waves can be retrieved through bin stacking,though further processing is still necessary to obtain finer waveforms such as P wave triplications.展开更多
We add new modules for receiver function （RF） analysis in SplitLab toolbox, which includes the manual RF analysis module, automatic RF analysis and related quality control modules, and H-k stacking module. The updat...We add new modules for receiver function （RF） analysis in SplitLab toolbox, which includes the manual RF analysis module, automatic RF analysis and related quality control modules, and H-k stacking module. The updated toolbox （named SplitRFLab toolbox）, espe- cially its automatic RF analysis module, could calculate the RFs quickly and efficiently, which is very useful in RF analysis with huge amount of seismic data. China is now conducting the ChinArray project that plans to deploy thousands of portable stations across Chinese mainland. Our SplitRFLab toolbox may obtain reliable RF results quickly at the first time, which provide essentially new constraint to the crustal and mantle structures.展开更多
文摘ChinArray is a dense portable broadband seismic network to cover the entire continental China, and the Phase I is deployed along the north-south seismic belt in southwest China. In this study, we analyze seismic data recorded on the ChinArray following the February 15, 2013 Chelyabinsk （Russia） meteor. This was the largest known object entering the Earth＇s atmosphere since the 1908 Tunguska meteor. The seismic energy radiated from this event was recorded by seismic stations worldwide including the dense ChinAn＇ay that are more than 4000 km away. The weak signal from the meteor event was con- taminated by a magnitude 5.8 Tonga earthquake occur- red ~ 20 min earlier. To test the feasibility of detecting the weak seismic signals from the meteor event, we compute vespagram and perform F-K analysis to the surface-wave data. We identify a seismic phase with back azimuth （BAZ） of 329.7° and slowness of 34.73 s/deg, corre- sponding to the surface wave from the Russian meteor event （BAZ ） 325.97°）. The surface magnitude （Ms） of the meteor event is 3.94 ±0.18. We also perform similar analysis on the data from the broadband array F-net in Japan, and find the BAZ of the surface waves to be 316.61%. With the different BAZs of ChinArray and F-net, we locate the Russian meteor event at 58.80°N, 58.72°E. The relatively large mislocation （-438 km as compared with 55.15°N. 61.41°E by others） may be a result of theweak signals at teleseismic distances.
基金sponsored by the National Key R&D Program of China(No.2018YFC1503200)National Science Foundation of China(No.42004046)。
文摘The vertical-vertical noise cross-correlation functions(NCFs)between two seismic arrays,the Japan F-net and Chin Array phase Ⅱ,are calculated using continuous recordings during 2013-2016.After array interferometry to obtain bin stacked NCFs,clear body waves are retrieved at different period bands.Teleseismic direct P waves for distance 15-40 degrees are observed between short period 3-10 s while core reflected PcP/ScS waves are more obvious for longer period 30-60 s.The signal-to-noise-ratio(SNR)of the short period P waves reaches its highest point with bin widths around 20 km while SNRs of PcP and ScS increase slowly with bin width.All those body waves demonstrate clear directivity with strong signals traveling from the east.The time-lapse SNR variations for the PcP and ScS show correlation with the occurrence of major earthquakes,while the P-wave SNR demonstrates seasonal variations with additional contribution from major earthquakes.The present results suggest teleseismic body waves can be retrieved through bin stacking,though further processing is still necessary to obtain finer waveforms such as P wave triplications.
基金supported by China National Special Fund for Earthquake Scientific Research in Public Interest(201008001,201308011)
文摘We add new modules for receiver function （RF） analysis in SplitLab toolbox, which includes the manual RF analysis module, automatic RF analysis and related quality control modules, and H-k stacking module. The updated toolbox （named SplitRFLab toolbox）, espe- cially its automatic RF analysis module, could calculate the RFs quickly and efficiently, which is very useful in RF analysis with huge amount of seismic data. China is now conducting the ChinArray project that plans to deploy thousands of portable stations across Chinese mainland. Our SplitRFLab toolbox may obtain reliable RF results quickly at the first time, which provide essentially new constraint to the crustal and mantle structures.
