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Suliyanti Pakpahan - One of the best experts on this subject based on the ideXlab platform.
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ANALISIS PARAMETERGEO-ATMOSFERIK DAN GEOKIMIA SEBAGAI PREKURSOR GEMPABUMI DI PELABUHAN RATU, SUKABUMI
Pusat Penelitian dan Pengembangan Badan Meteorologi Klimatologi dan Geofisika, 2015Co-Authors: Suliyanti Pakpahan, Boko Nurdiyanto, Drajat NgadmantoAbstract:Monitoring parameter geo-atmosferik dan geokimia sebagai perpaduan dari monitoring emisi gas radon, suhu udara permukaan, suhu dan kelembaban tanah dilakukan di Stasiun Observatori Geofisika Pelabuhan Ratu, Sukabumi, Jawa Barat untuk mengetahui hubungannya dengan aktivitas gempabumi. Penelitian di Indonesia mengenai hubungan parameter geo-atmosferik dan geokimia dengan prekursor gempabumi baru pertama kali dilakukan oleh Pusat Penelitian dan Pengembangan Badan Meteorologi Klimatologi dan Geofisika (Puslitbang BMKG). Monitoring gas radon, suhu, dan kelembaban tanah dilakukan menggunakan sistem monitoring radon RAD7 dengan sensor soil gas probe yang ditanam pada kedalaman 1,2 meter. Data pengamatan suhu permukaan adalah suhu maksimum dan minimum yang tercatat menggunakan termometer air raksa. Anomali radon, suhu, dan kelembaban dikorelasikan dengan kejadian gempabumi yang memenuhi radius zona manifestasi prekursor berdasarkan penelitian Dobrovolsky. Hasil analisis parameter geo-atmosferik menunjukkan adanya penurunan sebesar 5,3°-13° yang diikuti kenaikan sebesar 6°-8,2° pada nilai Tmax-Tmin suhu permukaan. Sementara untuk analisis geokimia menunjukkan adanya kenaikan gas radon sebesar 1,5-60 kali dari nilai normalnya, kenaikan kelembaban sebesar 6%-21%, dan kenaikan suhu tanah 1,5°-3,2° yang diikuti penurunan sebesar 1,5°-4°. Anomali geo-atmosferik dan geokimia yang diduga sebagai prekursor gempabumi terdeteksi 3-30 hari sebelum gempabumi sehingga parameter ini termasuk dalam prekursor jangka pendek yang berhubungan dengan proses deformasi di wilayah pengamatan sebelum gempabumi. Monitoring of geo-atmospheric and geochemical parameters, as a combination monitoring of radon emission, surface air temperature, and soil temperature and humidity, located in Geophysical Observatory Station Pelabuhan Ratu, Sukabumi, West Java, to determine its relation with Earthquake. In Indonesia, it was first research of Earthquake Precursor using these method, conducted by Research and Development Center, Indonesian Agency of Meteorology Climatology and Geophysics. Monitoring of radon, soil temperature and humidity using RAD7 radon monitoring system where probes sensor are placed at 1.2 meters below land surface. The maximum and minimum air temperature recorded by a mercury thermometer. The anomalies of radon, temperature and humidity are correlated with the occurrence of Earthquake within radius of Precursor manifestation zone, refer to Dobrovolsky's research. The results of analysis show a decrease of 5.3°-13° which followed by an increase of 6°-8.2° on the surface temperature; an increase of radon gas at 1.5-60 times of the normal value, the increase of humidity ranged on 6% -21%, and the soil temperature rise of 1.5°-3.2° followed by a decrease of 1.5°-4°. Geo-atmospheric and geochemical anomalies which indicated as Precursors, detected 3-30 days before Earthquake and categorized as short-term Precursors that associated withdeformation process in the observation region before Earthquake
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analisis parametergeo atmosferik dan geokimia sebagai prekursor gempabumi di pelabuhan ratu sukabumi Earthquake Precursors analysis using geo atmospheric and geochemical parameters in geophysical observatory station pelabuhan ratu sukabumi
2014Co-Authors: Suliyanti PakpahanAbstract:Monitoring of geo-atmospheric and geochemical parameters, as a combination monitoring of radon emission, surface air temperature, and soil temperatureand soil humidity, located in Geophysical Observatory Station Pelabuhan Ratu, Sukabumi, West Java, to determine its relation with Earthquake. In Indonesia, it was first research of Earthquake Precursor using these method, conducted by Research and Development Center, Indonesian Agency of Meteorology Climatology and Geophysics. Monitoring of radon, soil temperature and humidity using RAD7 radon monitoring system where probes sensor are placed at 1.2 meters below land surface. The maximum and minimum air temperature recorded by a mercury thermometer. The anomalies of radon, temperature and humidity are correlated with the occurrence of Earthquake withinradius of Precursor manifestation zone, refer to Dobrovolsky's research. The results of analysis show a decrease of 5.3°-13° which followed by an increase of 6°-8.2° on the surface temperature;an increase of radon gas at 1.560 times of the normal value, the increase of humidity ranged on 6% -21%, and the soil temperature rise of 1.5°-3.2° followed by a decrease of 1.5°-4°. Geo-atmospheric and geochemical anomalies which indicated as Precursors, detected 3-30 days before Earthquake and categorized as short-term Precursors that associated withdeformation process in the observation region before Earthquake.
Steven A Cummer - One of the best experts on this subject based on the ideXlab platform.
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Modelling Electromagnetic Propagation
2016Co-Authors: Steven A CummerAbstract:Abstract—The ionosphere plays a role in radio propagation that varies strongly with frequency. At extremely low frequency (ELF: 3–3000 Hz) and very low frequency (VLF: 3–30 kHz), the ground and the ionosphere are good electrical conductors and form a spherical earth–ionosphere waveguide. Many giants of the electromagnetics (EMs) community studied ELF-VLF propagation in the earth–ionosphere waveguide, a topic which was critically important for long-range communication and navigation systems. James R. Wait was undoubtedly the most prolific publisher in this field, starting in the 1950s and continuing well into the 1990s. Although it is an old problem, there are new scientific and practical applications that rely on accurate modeling of ELF-VLF propagation, including ionospheric remote sensing, lightning remote sensing, global climate monitoring, and even Earthquake Precursor detection. The theory of ELF-VLF propagation in the earth-ionosphere waveguide is mature, but there remain many ways of actually performing propagation cal-culations. Most techniques are based on waveguide mode theory with either numerical or approximate analytical formulations, but direct finite-difference time-domain (FDTD) modeling is now also feasible. Furthermore, in either mode theory or FDTD, the ionospheric upper boundary can be treated with varying degrees of approximation. While these approximations are understood in a qualitative sense, it is difficult to assess in advance their applicability to a given propagation problem. With a series of mode theory and FDTD simulations of propagation from lightning radiation in the earth–ionosphere waveguide, we investigate the accuracy of these approximations. We also show that fields from post-discharge ionospheric currents and from evanescent modes become important at lower ELF ( 500 Hz) over short distances ( 500 km). These fields are not easily modeled with mode theory, but are inherent in the FDTD formulation of the problem. In this way, the FDTD solution bridges the gap between analytical solutions for fields close to and far from the source. Index Terms—Earth–ionosphere waveguide. I
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Modeling electromagnetic propagation in the Earth-ionosphere waveguide
IEEE Transactions on Antennas and Propagation, 2000Co-Authors: Steven A CummerAbstract:The ionosphere plays a role in radio propagation that varies strongly with frequency. At extremely low frequency (ELF: 3–3000 Hz) and very low frequency (VLF: 3–30 kHz), the ground and the ionosphere are good electrical conductors and form a spherical earth–ionosphere waveguide. Many giants of the electromagnetics (EMs) community studied ELF-VLF propagation in the earth–ionosphere waveguide, a topic which was critically important for long-range communication and navigation systems. James R. Wait was undoubtedly the most prolific publisher in this field, starting in the 1950s and continuing well into the 1990s. Although it is an old problem, there are new scientific and practical applications that rely on accurate modeling of ELF-VLF propagation, including ionospheric remote sensing, lightning remote sensing, global climate monitoring, and even Earthquake Precursor detection. The theory of ELF-VLF propagation in the earth-ionosphere waveguide is mature, but there remain many ways of actually performing propagation cal- culations. Most techniques are based on waveguide mode theory with either numerical or approximate analytical formulations, but direct finite-difference time-domain (FDTD) modeling is now also feasible. Furthermore, in either mode theory or FDTD, the ionospheric upper boundary can be treated with varying degrees of approximation. While these approximations are understood in a qualitative sense, it is difficult to assess in advance their applicability to a given propagation problem. With a series of mode theory and FDTD simulations of propagation from lightning radiation in the earth–ionosphere waveguide, we investigate the accuracy of these approximations. We also show that fields from post-discharge ionospheric currents and from evanescent modes become important at lower ELF (  ??? Hz) over short distances (  ??? km). These fields are not easily modeled with mode theory, but are inherent in the FDTD formulation of the problem. In this way, the FDTD solution bridges the gap between analytical solutions for fields close to and far from the source.
Drajat Ngadmanto - One of the best experts on this subject based on the ideXlab platform.
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ANALISIS PARAMETERGEO-ATMOSFERIK DAN GEOKIMIA SEBAGAI PREKURSOR GEMPABUMI DI PELABUHAN RATU, SUKABUMI
Pusat Penelitian dan Pengembangan Badan Meteorologi Klimatologi dan Geofisika, 2015Co-Authors: Suliyanti Pakpahan, Boko Nurdiyanto, Drajat NgadmantoAbstract:Monitoring parameter geo-atmosferik dan geokimia sebagai perpaduan dari monitoring emisi gas radon, suhu udara permukaan, suhu dan kelembaban tanah dilakukan di Stasiun Observatori Geofisika Pelabuhan Ratu, Sukabumi, Jawa Barat untuk mengetahui hubungannya dengan aktivitas gempabumi. Penelitian di Indonesia mengenai hubungan parameter geo-atmosferik dan geokimia dengan prekursor gempabumi baru pertama kali dilakukan oleh Pusat Penelitian dan Pengembangan Badan Meteorologi Klimatologi dan Geofisika (Puslitbang BMKG). Monitoring gas radon, suhu, dan kelembaban tanah dilakukan menggunakan sistem monitoring radon RAD7 dengan sensor soil gas probe yang ditanam pada kedalaman 1,2 meter. Data pengamatan suhu permukaan adalah suhu maksimum dan minimum yang tercatat menggunakan termometer air raksa. Anomali radon, suhu, dan kelembaban dikorelasikan dengan kejadian gempabumi yang memenuhi radius zona manifestasi prekursor berdasarkan penelitian Dobrovolsky. Hasil analisis parameter geo-atmosferik menunjukkan adanya penurunan sebesar 5,3°-13° yang diikuti kenaikan sebesar 6°-8,2° pada nilai Tmax-Tmin suhu permukaan. Sementara untuk analisis geokimia menunjukkan adanya kenaikan gas radon sebesar 1,5-60 kali dari nilai normalnya, kenaikan kelembaban sebesar 6%-21%, dan kenaikan suhu tanah 1,5°-3,2° yang diikuti penurunan sebesar 1,5°-4°. Anomali geo-atmosferik dan geokimia yang diduga sebagai prekursor gempabumi terdeteksi 3-30 hari sebelum gempabumi sehingga parameter ini termasuk dalam prekursor jangka pendek yang berhubungan dengan proses deformasi di wilayah pengamatan sebelum gempabumi. Monitoring of geo-atmospheric and geochemical parameters, as a combination monitoring of radon emission, surface air temperature, and soil temperature and humidity, located in Geophysical Observatory Station Pelabuhan Ratu, Sukabumi, West Java, to determine its relation with Earthquake. In Indonesia, it was first research of Earthquake Precursor using these method, conducted by Research and Development Center, Indonesian Agency of Meteorology Climatology and Geophysics. Monitoring of radon, soil temperature and humidity using RAD7 radon monitoring system where probes sensor are placed at 1.2 meters below land surface. The maximum and minimum air temperature recorded by a mercury thermometer. The anomalies of radon, temperature and humidity are correlated with the occurrence of Earthquake within radius of Precursor manifestation zone, refer to Dobrovolsky's research. The results of analysis show a decrease of 5.3°-13° which followed by an increase of 6°-8.2° on the surface temperature; an increase of radon gas at 1.5-60 times of the normal value, the increase of humidity ranged on 6% -21%, and the soil temperature rise of 1.5°-3.2° followed by a decrease of 1.5°-4°. Geo-atmospheric and geochemical anomalies which indicated as Precursors, detected 3-30 days before Earthquake and categorized as short-term Precursors that associated withdeformation process in the observation region before Earthquake
Bornali Chetia - One of the best experts on this subject based on the ideXlab platform.
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a novel approach for ionospheric total electron content Earthquake Precursor and epicenter detection for low latitude
International Journal of Engineering, 2020Co-Authors: Santanu Kalita, Bornali ChetiaAbstract:The Earthquake Precursory phenomena detection using ionospheric perturbation characteristics is a new technique used by the scientist now days. This paper focuses a new technique for detecting any modification in the time series profile shape caused by an impending Earthquake to identify Precursors as well as an image processing technique for epicenter detection. For this purpose IGS Global Navigation Satellite System (GNSS) Total Electron Content Data (TEC) are utilized from different stations across the world. From the experiment it is observed that the method may detect Earthquake Precursors a few hours or days prior to the main event due to ionospheric perturbations induced by initiation of Earthquake process.
Santanu Kalita - One of the best experts on this subject based on the ideXlab platform.
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a novel approach for ionospheric total electron content Earthquake Precursor and epicenter detection for low latitude
International Journal of Engineering, 2020Co-Authors: Santanu Kalita, Bornali ChetiaAbstract:The Earthquake Precursory phenomena detection using ionospheric perturbation characteristics is a new technique used by the scientist now days. This paper focuses a new technique for detecting any modification in the time series profile shape caused by an impending Earthquake to identify Precursors as well as an image processing technique for epicenter detection. For this purpose IGS Global Navigation Satellite System (GNSS) Total Electron Content Data (TEC) are utilized from different stations across the world. From the experiment it is observed that the method may detect Earthquake Precursors a few hours or days prior to the main event due to ionospheric perturbations induced by initiation of Earthquake process.