26 research outputs found

    ТЕМПЕРАТУРНЫЕ АНОМАЛИИ ПЕРЕД ЗЕМЛЕТРЯСЕНИЕМ В ПРОВИНЦИИ ГОРКХА (НЕПАЛ) В 2015 Г., УСТАНОВЛЕННЫЕ ПО ЗНАЧЕНИЯМ ТЕМПЕРАТУРЫ ПОВЕРХНОСТИ ЗЕМЛИ MODIS И УХОДЯЩЕГО ДЛИННОВОЛНОВОГО ИЗЛУЧЕНИЯ

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    Earthquakes can generate thermal anomalies in the atmosphere at low altitudes. Pending well-focused detailed studies, such phenomenon may be referred to as a precursor for earthquake prediction. However, today the pre-earthquake thermal anomalies are not clear enough. In this paper, the thermal anomalies prior to the April 25, 2015 Mw 7.8 Gorkha (Nepal) earthquake are investigated from the Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST), air temperature and Outgoing Longwave Radiations (OLR) data. The 2D and 3D wavelet transformation techniques are used to interpret the real time enhancement of the daily MODIS and OLR data before the impending earthquake. Using the wavelet density spectrum, pre-earthquake anomalies in MODIS and OLR are found in connection to the impending earthquake. The spatial images of MODIS and OLR show the evolutionary pattern of the emanation of ions from the epicenter and the surrounding area. The most important feature revealed by the spatial analysis is the eastward migration of temperature clouds due to a strong electric field. The satellite based LST data showed deviation, which crosses the upper bound by 5 °C. All the observations in our case study strongly support the notion of pre-earthquake thermal anomalies. Based on the analysis of the results, it can be concluded that the overabundance of ions from the seismogenic zone is responsible for prompting large temperature perturbations in atmospheric layers.Землетрясения способны создавать тепловые аномалии в атмосфере на малых высотах. Такие аномалии могут рассматриваться в качестве вероятного предвестника при прогнозирования землетрясений, в связи с чем требуются целенаправленные детальные исследования. На сегодня знаний о тепловых аномалиях, появляющихся перед землетрясениями, недостаточно. В статье представлены результаты изучения термических аномалий, имевших место перед землетрясением в провинции Горкха (Непал) (Mw=7.8) 25 апреля 2015 г., как свидетельствуют значения температуры поверхности Земли, зарегистрированные сканирующими спектрорадиометрами среднего разрешения MODIS, а также данные о температуре атмосферного воздуха и уходящего длинноволнового излучения (OLR). Метод вейвлет-преобразования в двух- и трехмерном пространстве использован для интерпретации повышения суточных значений MODIS и OLR в реальном времени накануне землетрясения. По спектральной плотности накануне реального сейсмического события установлены аномальные значения MODIS и OLR, связанные с приближением этого землетрясения. Пространственные снимки MODIS и OLR показывают эволюционирующий характер эманации ионов из эпицентра и прилегающей области. Наиболее важной особенностью, выявленной посредством пространственного анализа, следует считать миграцию температурных облаков в восточном направлении вследствие усилившегося электрического поля. Спутниковые данные LST показывают отклонение от верхней границы значений на 5 °C. Все наблюдения в нашем исследовании подтверждают понятие тепловых аномалий накануне землетрясения. Исходя из анализа результатов, можно сделать вывод, что избыток ионов из сейсмогенной зоны обусловливает появление больших температурных возмущений в слоях атмосферы

    The Gravity Environment of Zhouqu Debris Flow of August 2010 and Its Implication for Future Recurrence

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    This study investigates the geological background of the August 7-8, 2010 Zhouqu debris flows in the northwestern Chinese province of Gansu, and possible future occurrence of such hazards in the peri-Tibetan Plateau (TP) regions. Debris flows are a more predictable type of landslide because of its strong correlation with extreme precipitation. However, two factors affecting the frequency and magnitude of debris flows: very fine scale precipitation and degree of fracture of bedrock, both defy direct observations. Annual mean Net Primary production (NPP) is used as a surrogate for regional precipitation with patchiness filtered out, and gravity satellite measured regional mass changes as an indication of bedrock cracking, through the groundwater as the nexus. The GRACE measurements indicate a region (to the north east of TP) of persistent mass gain (started well before the 2008 Wenchuan earthquake), likely due to increased groundwater percolation. While in the neighboring agricultural region further to the north east, there are signal of decreased fossil water reservoir. The imposed stress fields by large scale increase/decrease groundwater may contribute to future geological instability of this region. Zhouqu locates right on the saddle of the gravity field anomaly. The region surrounding the Bay of Bangle (to the southeast of TP) has a similar situation. To investigate future changes in extreme precipitation, the other key player for debris flows, the “pseudo-climate change” experiments of a weather model forced by climate model provided perturbations on the thermal fields are performed and endangered locations are identified. In the future warmer climate, extreme precipitation will be more severe and debris will be more frequent and severe

    Atmospheric and ionospheric coupling phenomena related to large earthquakes

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    This paper explores multi-instrument space-borne observations in order to validate physical concepts of Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) in relation to major seismic events. In this study we apply already validated observation to identify atmospheric and ionospheric precursors associated with some of recent most destructive earthquakes: M8.6 of March 25, 2005 and M8.5 September 15, 2007 in Sumatra, and M7.9 May 12, 2008 in Wenchuan, China. New investigations are also presented concerning these three earthquakes and for the M7.3 March 2008 in the Xinjiang-Xizang border region, China (the Yutian earthquake). It concerns the ionospheric density, the Global Ionospheric Maps (GIM) of the Total Electron Content (TEC), the Thermal Infra-Red (TIR) anomalies, and the Outgoing Longwave Radiation (OLR) data. It is shown that all these anomalies are identified as short-term precursors, which can be explained by the LAIC concept proposed by Pulinets and Ouzounov (2011)

    Variations of multi-parameter observations in atmosphere related to earthquake

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    Anomalies of multi-parameters (outgoing longwave radiation, surface latent heat flux, air temperature, relative humidity, and air pressure) before the 12 May 2008 Wenchuan <i>M</i><sub>s</sub> =8.0 earthquake were discussed in order to obtain the seismic precursors. Multi-parameter data were computed based on multi-year background data. The results indicated that these parameters had significant variations prior to this event. The anomaly of outgoing longwave radiation was observed firstly, which gives an early warning. Next were air temperature, relative humidity, and air pressure, which had quasi-simultaneous variations in the basin and the mountain region close to the epicenter. The last was surface latent heat flux, which happened the day before this event. The characteristics of the parameter variations for this event are similar to other earthquakes, which is demonstrated in some other publications. The variations can be attributed to solid earth degassing and chemical reactions in the atmosphere. Additionally, the emission of gases from solid earth into the atmosphere could be ascribed to the tectonic stress of the Wenchuan earthquake

    Atmospheric and ionospheric coupling phenomena associated with large earthquakes

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    This paper explores multi-instrument space-borne observations in order to validate physical concepts of Lithosphere-AtmosphereIonosphere Coupling (LAIC) in relation to a selection of major seismic events. In this study we apply some validated techniques to observations in order to identify atmospheric and ionospheric precursors associated with some of recent most destructive earthquakes: M8.6 of March 28, 2005 and M8.5 of Sept. 12, 2007 in Sumatra, and M7.9 of May 12, 2008 in Wenchuan, China. New investigations are also presented concerning these three earthquakes and for the M7.2 of March 2008 in the Xinjiang-Xizang border region, China (the Yutian earthquake). It concerns the ionospheric density, the Global Ionospheric Maps (GIM) of the Total Electron Content (TEC), the Thermal InfraRed (TIR) anomalies, and the Outgoing Longwave Radiation (OLR) data. It is shown that all these anomalies are identified as short-term precursors, which can be explained by the LAIC concept proposed in [S. Pulinets, D. Ouzounov, J. Asian Earth Sci. 41, 371 (2011)]

    From visual comparison to robust satellite techniques: 30 years of thermal infrared satellite data analyses for the study of earthquake preparation phases

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    This review paper reports the main contributions and results achieved after more than 30 years of studies on the possible relationships among space-time variation of Earth’s thermally emitted radiation, measured by satellite sensors operating in the Thermal InfraRed (TIR) spectral range (8-14 m), and earthquake occurrence. Focus will be given on the different existing methods/models to: 1) discriminate a possible pre-seismic TIR anomaly from all the other TIR signal fluctuations; 2) correlate such anomalies with space, time and magnitude of earthquakes; 3) physically justify such a correlation

    Thermal Radiation Anomalies Associated with Major Earthquakes

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    Recent developments of remote sensing methods for Earth satellite data analysis contribute to our understanding of earthquake related thermal anomalies. It was realized that the thermal heat fluxes over areas of earthquake preparation is a result of air ionization by radon (and other gases) and consequent water vapor condensation on newly formed ions. Latent heat (LH) is released as a result of this process and leads to the formation of local thermal radiation anomalies (TRA) known as OLR (outgoing Longwave radiation, Ouzounov et al, 2007). We compare the LH energy, obtained by integrating surface latent heat flux (SLHF) over the area and time with released energies associated with these events. Extended studies of the TRA using the data from the most recent major earthquakes allowed establishing the main morphological features. It was also established that the TRA are the part of more complex chain of the short-term pre-earthquake generation, which is explained within the framework of a lithosphere-atmosphere coupling processes

    Geosystemics View of Earthquakes

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    Earthquakes are the most energetic phenomena in the lithosphere: their study and comprehension are greatly worth doing because of the obvious importance for society. Geosystemics intends to study the Earth system as a whole, looking at the possible couplings among the different geo-layers, i.e., from the earth’s interior to the above atmosphere. It uses specific universal tools to integrate different methods that can be applied to multi-parameter data, often taken on different platforms (e.g., ground,marine or satellite observations). Itsmain objective is to understand the particular phenomenon of interest from a holistic point of view. Central is the use of entropy, together with other physical quantities that will be introduced case by case. In this paper, we will deal with earthquakes, as final part of a long-term chain of processes involving, not only the interaction between different components of the Earth’s interior but also the coupling of the solid earth with the above neutral or ionized atmosphere, and finally culminating with the main rupture along the fault of concern. Particular emphasis will be given to some Italian seismic sequences.Publishedid 4121A. Geomagnetismo e PaleomagnetismoJCR Journa

    Transient effects in atmosphere and ionosphere preceding the 2015 M7.8 and M7.3 Gorkha–Nepal earthquakes

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    We analyze retrospectively/prospectively the transient variations of six different physical parameters in the atmosphere/ionosphere during the M7.8 and M7.3 earthquakes in Nepal, namely: 1) outgoing longwave radiation (OLR) at the top of the atmosphere (TOA); 2) GPS/TEC; 3) the very-low-frequency (VLF/LF) signals at the receiving stations in Bishkek (Kyrgyzstan) and Varanasi (India); 4) Radon observations; 5) Atmospheric chemical potential from assimilation models; and; 6) Air Temperature from NOAA ground stations. We found that in mid-March 2015, there was a rapid increase in the radiation from the atmosphere observed by satellites. This anomaly was located close to the future M7.8 epicenter and reached a maximum on April 21–22. The GPS/TEC data analysis indicated an increase and variation in electron density, reaching a maximum value during April 22–24. A strong negative TEC anomaly in the crest of EIA (Equatorial Ionospheric Anomaly) occurred on April 21, and a strong positive anomaly was recorded on April 24, 2015. The behavior of VLF-LF waves along NWC-Bishkek and JJY-Varanasi paths has shown abnormal behavior during April 21–23, several days before the first, stronger earthquake. Our continuous satellite OLR analysis revealed this new strong anomaly on May 3, which was why we anticipated another major event in the area. On May 12, 2015, an M7.3 earthquake occurred. Our results show coherence between the appearance of these pre-earthquake transient’s effects in the atmosphere and ionosphere (with a short time-lag, from hours up to a few days) and the occurrence of the 2015 M7.8 and M7.3 events. The spatial characteristics of the pre-earthquake anomalies were associated with a large area but inside the preparation region estimated by Dobrovolsky-Bowman. The pre-earthquake nature of the signals in the atmosphere and ionosphere was revealed by simultaneous analysis of satellite, GPS/TEC, and VLF/LF and suggest that they follow a general temporal-spatial evolution pattern that has been seen in other large earthquakes worldwide

    Production of semi-real time media-GIS contents of natural disasters using MODIS satellite data

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    In the event of a natural disaster, the information provided to the public can play an important role in its mitigation and management. Use of media-GIS content has been shown to provide information that is visual and accessible to the public. This report focuses on the information provided to the public through the media and develops rigorous production methods and quality practices to encourage increased strategic use of media-GIS content. The report utilizes three natural disaster case studies to evaluate the production method and presents recommendations and conclusions based on the information these provide. Previous studies identified five aspects that are important to media-GIS contents. These are accuracy, high aesthetic quality, speed, low cost and reusability. A review of MODIS imagery has shown it to sufficiently satisfy all five aspects. The report identifies an ideal source of MODIS data and a production method based on the information available to be obtained. By applying this methodology to the three case studies, it was found that the process could be more streamlined than previously identified methods. Further observations identified both positive and negative aspects of the method allowing improvements to be made were possible. Whilst limitations of MODIS were identified, the properties of MODIS data make it evident that it is the most effective source of satellite data for the production of media-GIS content where time and cost need to be minimised. Completion of the case studies led to the production of a guidebook, presented in Appendix F, which is intended to be issued to media outlets as an instruction manual for producing media-GIS contents. It is hoped that this will encourage an increase in the use of GIS within the media industry and provide thorough production method and quality practices information
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