Seismic data coverage in ocean regions is sparse,and it is highly challenging to build long-term continuous seismic networks in the oceans due to the restrictions related to the shortage of instruments and great costs...Seismic data coverage in ocean regions is sparse,and it is highly challenging to build long-term continuous seismic networks in the oceans due to the restrictions related to the shortage of instruments and great costs.The lack of data coverage limits effective seismic imaging of deep mantle structures beneath the oceans,which cover 70%of the Earth’s surface.The newly developed Mobile Earthquake Recorder in Marine Areas by Independent Drivers(MERMAID)can drift with ocean currents at a specified depth while recording seismic signals.The Southern University of Science and Technology(SUSTech)launched 10 MERMAIDs in the South China Sea(SCS)in May 2021 that formed the South China Sea Floating Seismic Network(SCS-FSN).We analyzed the one-year-long records of the SCS-FSN,identifying 372 cataloged earthquakes and acquiring 1,015 high-quality travel time data.By analyzing the records of earthquakes with magnitudes above 7.0 and conducting synthetic waveform calculation,we found that,in addition to the epicentral distance and earthquake magnitude,the earthquake identification ability of the network is also affected by the focal mechanism,sea condition,seafloor relief,and MERMAID working state.Although the recognition rate of the SCS-FSN is only 16%for earthquakes with magnitudes above 5.5 and epicentral distances less than 90°,this network is expected to collect more than 5,000 high-quality travel time data during its five-year battery life.These new data will significantly improve the seismic data coverage,compensating for the lack of long-term continuous seismic network observations in the SCS.Most importantly,with this experiment,we are confident that setting up well-designed floating seismic networks in the world’s three oceans could solve the world-class problem of the lack of effective seismic data coverage beneath ocean regions.展开更多
Being an extremely confusing image, the Mermaid is the key to approach the theme of The Love Song of J. Alfred Prufrock. With a touch of irony, the narrator exposes his helplessness and cowardice. Accompanied by the a...Being an extremely confusing image, the Mermaid is the key to approach the theme of The Love Song of J. Alfred Prufrock. With a touch of irony, the narrator exposes his helplessness and cowardice. Accompanied by the appearing of the mermaid, the ironic tone of poem turns tender, the scene has shifted from reality to imagination, and the narrator is no longer sophisticated but romantic. Moreover, because of the juxtaposition of the fragmentary scenes, the poem seems disorderly, however, the image of mermaid endows the poem an explicit structure in which the ＂waste land＂ theme is contained.展开更多
基金supported by the NSFC Open Research Cruise (Cruise No. NORC2021-08)funded by Shiptime Sharing Project of the NSFC+1 种基金supported by the National Natural Science Foundation of China (Grant No. 41890814)the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)
文摘Seismic data coverage in ocean regions is sparse,and it is highly challenging to build long-term continuous seismic networks in the oceans due to the restrictions related to the shortage of instruments and great costs.The lack of data coverage limits effective seismic imaging of deep mantle structures beneath the oceans,which cover 70%of the Earth’s surface.The newly developed Mobile Earthquake Recorder in Marine Areas by Independent Drivers(MERMAID)can drift with ocean currents at a specified depth while recording seismic signals.The Southern University of Science and Technology(SUSTech)launched 10 MERMAIDs in the South China Sea(SCS)in May 2021 that formed the South China Sea Floating Seismic Network(SCS-FSN).We analyzed the one-year-long records of the SCS-FSN,identifying 372 cataloged earthquakes and acquiring 1,015 high-quality travel time data.By analyzing the records of earthquakes with magnitudes above 7.0 and conducting synthetic waveform calculation,we found that,in addition to the epicentral distance and earthquake magnitude,the earthquake identification ability of the network is also affected by the focal mechanism,sea condition,seafloor relief,and MERMAID working state.Although the recognition rate of the SCS-FSN is only 16%for earthquakes with magnitudes above 5.5 and epicentral distances less than 90°,this network is expected to collect more than 5,000 high-quality travel time data during its five-year battery life.These new data will significantly improve the seismic data coverage,compensating for the lack of long-term continuous seismic network observations in the SCS.Most importantly,with this experiment,we are confident that setting up well-designed floating seismic networks in the world’s three oceans could solve the world-class problem of the lack of effective seismic data coverage beneath ocean regions.
文摘Being an extremely confusing image, the Mermaid is the key to approach the theme of The Love Song of J. Alfred Prufrock. With a touch of irony, the narrator exposes his helplessness and cowardice. Accompanied by the appearing of the mermaid, the ironic tone of poem turns tender, the scene has shifted from reality to imagination, and the narrator is no longer sophisticated but romantic. Moreover, because of the juxtaposition of the fragmentary scenes, the poem seems disorderly, however, the image of mermaid endows the poem an explicit structure in which the ＂waste land＂ theme is contained.
