This article describes an improved data acquisition system from a previous system dedicated to one-sensor site studies, aimed at recording ambient vibrations (microtremors). A multi-channel and/or remote triggering sy...This article describes an improved data acquisition system from a previous system dedicated to one-sensor site studies, aimed at recording ambient vibrations (microtremors). A multi-channel and/or remote triggering system is proposed. The system was conceived by IRD-Leas, France, and used at ISTerre, France, for research activities. The size, weight of this high quality system and its autonomy (no need to be connected to a laptop) make it a real portable device. The system acquires data with 24-bit delta-sigma ADCs in the 10 - 1000 sps range at 10 - 20 bit resolution on up to 18 channels in the multi-channel version. The input stage dynamics is available at ±2.5 V or ±5 V. The dynamic range varies, for example, from 108 dB at 100 sps to 90 dB at 250 sps. Gain is selectable from 1 (0 dB) to 8192 (78 dB) by powers of two (6 dB). Its very low level of internal noise allows recording of very low tension signals without missing code. Continuous recording and GPS may also be implemented in the system. While primarily dedicated to ambient vibration recordings, this system can be connected to any type of device delivering an output tension in the ±5 V range.展开更多
Earthquakes are classified as one of the most devastating natural disasters that can have catastrophic effects on the environment,lives,and properties.There has been an increasing interest in the prediction of earthqu...Earthquakes are classified as one of the most devastating natural disasters that can have catastrophic effects on the environment,lives,and properties.There has been an increasing interest in the prediction of earthquakes and in gaining a comprehensive understanding of the mechanisms that underlie their generation,yet earthquakes are the least predictable natural disaster.Satellite data,global positioning system,interferometry synthetic aperture radar(InSAR),and seismometers such as microelectromechanical system,seismometers,ocean bottom seismometers,and distributed acoustic sensing systems have all been used to predict earthquakes with a high degree of success.Despite advances in seismic wave recording,storage,and analysis,earthquake time,location,and magnitude prediction remain difficult.On the other hand,new developments in artificial intelligence(AI)and the Internet of Things(IoT)have shown promising potential to deliver more insights and predictions.Thus,this article reviewed the use of AI-driven Models and IoT-based technologies for the prediction of earthquakes,the limitations of current approaches,and open research issues.The review discusses earthquake prediction setbacks due to insufficient data,inconsistencies,diversity of earthquake precursor signals,and the earth’s geophysical composition.Finally,this study examines potential approaches or solutions that scientists can employ to address the challenges they face in earthquake prediction.The analysis is based on the successful application of AI and IoT in other fields.展开更多
The Yecheng-Shiquanhe profile runs over the western Tibetan Plateau from the south margin of the Tarim Basin, crossing the west Kunlun orogeny, to the east of Karakorum. The authors applied body waves to 3-dimensional...The Yecheng-Shiquanhe profile runs over the western Tibetan Plateau from the south margin of the Tarim Basin, crossing the west Kunlun orogeny, to the east of Karakorum. The authors applied body waves to 3-dimensional inversion of travel time residuals and outlined the deep tectonic pattern of the northwestern Tibetan Plateau. An image was obtained, showing that the Tarim lithosphere is subducted southwards underneath the west Kunlun orogeny at an angle of 40° and a depth of 280 km. Surface structures are well expressed in the image and can be further traced in deeper levels. The prominent finding is that the Gozha Fault and Karakax Fault are likely to join together beyond a depth of ～200 km, which is the very zone of active seismicity.展开更多
基金funded by IRD(Institut de Recherche pour le Developpement),a French public research institute,and LEAS company.
文摘This article describes an improved data acquisition system from a previous system dedicated to one-sensor site studies, aimed at recording ambient vibrations (microtremors). A multi-channel and/or remote triggering system is proposed. The system was conceived by IRD-Leas, France, and used at ISTerre, France, for research activities. The size, weight of this high quality system and its autonomy (no need to be connected to a laptop) make it a real portable device. The system acquires data with 24-bit delta-sigma ADCs in the 10 - 1000 sps range at 10 - 20 bit resolution on up to 18 channels in the multi-channel version. The input stage dynamics is available at ±2.5 V or ±5 V. The dynamic range varies, for example, from 108 dB at 100 sps to 90 dB at 250 sps. Gain is selectable from 1 (0 dB) to 8192 (78 dB) by powers of two (6 dB). Its very low level of internal noise allows recording of very low tension signals without missing code. Continuous recording and GPS may also be implemented in the system. While primarily dedicated to ambient vibration recordings, this system can be connected to any type of device delivering an output tension in the ±5 V range.
文摘Earthquakes are classified as one of the most devastating natural disasters that can have catastrophic effects on the environment,lives,and properties.There has been an increasing interest in the prediction of earthquakes and in gaining a comprehensive understanding of the mechanisms that underlie their generation,yet earthquakes are the least predictable natural disaster.Satellite data,global positioning system,interferometry synthetic aperture radar(InSAR),and seismometers such as microelectromechanical system,seismometers,ocean bottom seismometers,and distributed acoustic sensing systems have all been used to predict earthquakes with a high degree of success.Despite advances in seismic wave recording,storage,and analysis,earthquake time,location,and magnitude prediction remain difficult.On the other hand,new developments in artificial intelligence(AI)and the Internet of Things(IoT)have shown promising potential to deliver more insights and predictions.Thus,this article reviewed the use of AI-driven Models and IoT-based technologies for the prediction of earthquakes,the limitations of current approaches,and open research issues.The review discusses earthquake prediction setbacks due to insufficient data,inconsistencies,diversity of earthquake precursor signals,and the earth’s geophysical composition.Finally,this study examines potential approaches or solutions that scientists can employ to address the challenges they face in earthquake prediction.The analysis is based on the successful application of AI and IoT in other fields.
基金suppoted by the Ministry of Land and Res ources,PRC(Grant No.20001010201)and CNRS of France.
文摘The Yecheng-Shiquanhe profile runs over the western Tibetan Plateau from the south margin of the Tarim Basin, crossing the west Kunlun orogeny, to the east of Karakorum. The authors applied body waves to 3-dimensional inversion of travel time residuals and outlined the deep tectonic pattern of the northwestern Tibetan Plateau. An image was obtained, showing that the Tarim lithosphere is subducted southwards underneath the west Kunlun orogeny at an angle of 40° and a depth of 280 km. Surface structures are well expressed in the image and can be further traced in deeper levels. The prominent finding is that the Gozha Fault and Karakax Fault are likely to join together beyond a depth of ～200 km, which is the very zone of active seismicity.
