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kalman filter and neural network methods for detecting irregular variations of tec around the time of powerful mexico (mw=8.2) earthquake of september 08, 2017
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نویسنده
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akhoondzadeh hanzaei m.
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منبع
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فيزيك زمين و فضا - 2019 - دوره : 44 - شماره : 4 - صفحه:87 -97
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چکیده
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In 98 km sw of tres picos in mexico (15.022°n, 93.899°w, 47.40 km depth) a powerful earthquake of mw=8.2 took place at 04:49:19 utc (lt=utc05:00) on september 8, 2017. in this study, using three standard, classical and intelligent methods including median, kalman filter, and neural network, respectively, the gps total electron content (tec) measurements of three months were surveyed to detect the potential unusual variations around the time and location of mexico earthquake. every three implemented methods indicated a striking irregular variation of tec at the earthquake time. however, on the earthquake day, the geomagnetic indices dst and ap have exceeded the allowed ranges and even reached maximum values during the studied time period. besides, the solar index of f10.7 showed high activity around the earthquake day. therefore, it is difficult to acknowledge the seismicity nature of the detected tec unusual variations on earthquake day. therefore, in this case, we encounter a mixed and complex behavior of ionosphere.
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کلیدواژه
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earthquake precursor ,ionosphere ,geomagnetic activity ,gps ,mexico earthquake ,tec
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آدرس
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university of tehran, school of surveying and geospatial engineering, college of engineering, department of remote sensing, ایران
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پست الکترونیکی
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makhonz@ut.ac.ir
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Kalman filter and Neural Network methods for detecting irregular variations of TEC around the time of powerful Mexico (Mw=8.2) earthquake of September 08, 2017
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Authors
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Akhoondzadeh Hanzaei Mehdi
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Abstract
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In 98 km SW of Tres Picos in Mexico (15.022°N, 93.899°W, 47.40 km depth) a powerful earthquake of Mw=8.2 took place at 04:49:19 UTC (LT=UTC05:00) on September 8, 2017. In this study, using three standard, classical and intelligent methods including median, Kalman filter, and Neural Network, respectively, the GPS Total Electron Content (TEC) measurements of three months were surveyed to detect the potential unusual variations around the time and location of Mexico earthquake. Every three implemented methods indicated a striking irregular variation of TEC at the earthquake time. However, on the earthquake day, the geomagnetic indices Dst and Ap have exceeded the allowed ranges and even reached maximum values during the studied time period. Besides, the solar index of F10.7 showed high activity around the earthquake day. Therefore, it is difficult to acknowledge the seismicity nature of the detected TEC unusual variations on earthquake day. Therefore, in this case, we encounter a mixed and complex behavior of ionosphere.
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Keywords
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Earthquake Precursor ,Ionosphere ,Geomagnetic activity ,GPS ,Mexico earthquake ,TEC
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