Study of thermal IR phenomena associated with 27 February 2010 Chile Mw 8.8 earthquake using MODIS data     

Vinod Kumar Kancherla  Colin Arrowsmith 《国际地球制图》2018,33(3):293-309

Stresses acting on fault systems before major earthquakes can produce thermal anomalies; these abnormalities can be observed using multi-sensor satellite data. Moderate resolution spectro-radiometer on board the terra and aqua satellites can provide thermal infrared (TIR) imaging data for land and ocean. These TIR data have recorded short-lived thermal anomaly prior to major earthquakes. It is suggested by others that these electromagnetic (EM) phenomena relate to stress build up before earthquakes. The objective of this study is to find an association between spatial extent and temporal evolution of thermal anomalies and known major earthquakes near the boundary of Nazca plate and South American plate. Our approach is to map the TIR transient fields from polar orbiting satellites and analysing those data using time series temperature plots to detect the abnormal thermal trends before the earthquake. This study concentrated on marine earthquakes to detect the changes in both land and ocean before seismic activity.  相似文献   

How turbidity current frequency and character varies down a fjord‐delta system: Combining direct monitoring,deposits and seismic data     

Cooper D. Stacey  Philip R. Hill  Peter J. Talling  Randolph J. Enkin  John Hughes Clarke  D. Gwyn Lintern 《Sedimentology》2019,66(1):1-31

Submarine turbidity currents are one of the most important processes for moving sediment across our planet; they are hazardous to offshore infrastructure, deposit petroleum reservoirs worldwide, and may record tsunamigenic landslides. However, there are few studies that have monitored these submarine flows in action, and even fewer studies that have combined direct monitoring with longer‐term records from core and seismic data of deposits. This article provides one of the most complete studies yet of a turbidity current system. The aim here is to understand what controls changes in flow frequency and character along the turbidite system. The study area is a 12 km long delta‐fed fjord (Howe Sound) in British Columbia, Canada. Over 100 often powerful (up to 2 to 3 m sec^?1) events occur each year in the highly‐active proximal channels, which extend for 1 to 2 km from the delta lip. About half of these events reach the lobes at the channel mouths. However, flow frequency decreases rapidly once these initially sand‐rich flows become unconfined, and only one to five flows run out across the mid‐slope each year. Many of these sand‐rich, channelized, delta‐sourced flows therefore dissipated over a few hundred metres, once unconfined, rather than eroding and igniting. Upflow migrating bedforms indicate that supercritical flow dominated in the proximal channels and lobes, and also across the unconfined mid‐slope. These supercritical flows deposited thick sand beds in proximal channels and lobes, but thinner and finer beds on the unconfined mid‐slope. The distal flat basin records far larger volume and more hazardous events that have a recurrence interval of ca 100 years. This study shows how sand‐rich delta‐fed flows dissipate rapidly once they become unconfined, that supercritical flows dominate in both confined and unconfined settings, and how a second type of more hazardous, and much less frequent event is linked to a different scale of margin failure.  相似文献   

地震及其前兆的观测研究与地震预测   总被引：8，自引：3，他引：5  

郝建国 《地震地磁观测与研究》1999,20(6):45-50

通过对地震灾害及预测观察研究现状的分析,解析了地震预测研究中存在的问题和不足,指出了地震及其前兆观测在预测研究中的作用,同时认为,地震前兆观测既不能盲目,也不能随波逐流也进行,其进展以决于地震孕育机理的深入理解和有效观测途径或方法的选择,并简述了２０年来在震前准静电场观测研究中取得进展和体会。  相似文献   

超临界水压力-体积-温度（PVT ）新数据的评价     

郭涛  胡家文  毛世德 《高校地质学报》2013,19(3):447

1990 年以来,超临界水的PVT 实验数据和分子动力学模拟数据已延伸到很高的温度和压力。文中详细评价了这些数 据的质量。国际水和水蒸汽性质学会所推出的1995 年版的水的状态方程（IAPWS95）被选作评价的可靠基础,同时辅以 其适当的外延。分析结果表明,Zhang and Duan （2005）的模拟数据和Abramson and Brown （2004）通过声速实验值反演 得到的PVT 数据与目前最精确的水的PVT 数据吻合得很好,但后者有较小的系统偏差。其它几组数据都有较大的系统偏差 或不确定度。其中,Belonoshko and Saxena （1991）的模拟数据P -T 范围很宽,但不确定度很大,而且有显著的系统偏差。 Brdoholt and Wood （1993）的模拟数据也有显著的系统偏差。随着压力的增加,这两组模拟数据的体积偏差都有由正转负 的趋势,其中后者尤为显著,而且在高压下离散性很弱,因而易于校正。Withers et al. （2000）,Brodholt and Wood （1994） 和Frost and Wood （1997）的实验数据都有明显的正偏差,其中前一组的偏差较小,后两组的偏差较大,原则上均可近似地 校正。Larrieu and Ayers （1997）的数据总体不确度较大,其中偏差较小的数据仅限于特定的温度和压力,其它数据的偏差 没有明显的规律。这些结果应当有助于上述新数据的正确使用和进一步优化。  相似文献   

地球深部物质科学——在静高压大腔体实验研究方面的某些进展   总被引：1，自引：0，他引：1  

谢鸿森  侯渭  周文戈  郑海飞  苏根利  朱卫国  郭捷 《地学前缘》2000,7(1):217-228

介绍近年来使用静态超高压大腔体实验技术 ,在模拟地球内部的高温高压条件下 ,对地球物质进行的若干物理和化学性质的实验研究。高压同时高温条件下多种岩石样品的弹性波速就位测量揭示出物质的声软化现象和振幅效应 ;高温高压下陨石和岩石的熔融结晶实验发现了陨石硅酸盐相的不混溶现象以及玄武岩熔体结构的变化 ,在玄武岩转变为榴辉岩的实验中观测到了刚玉相 ;在高温高压水的实验中 ,发现了冰 Ⅶ 的亚稳相和熔融前效应以及超临界水及其稀溶液的一些新性质。这些实验结果为探索地球深部物质的性质和状态以及迁移和演化提供了新的依据。  相似文献   

高光谱影像处理方法的改进   总被引：8，自引：2，他引：6  

杨哲海  冯猛  张燕燕 《海洋测绘》2004,24(4):13-16

介绍了高光谱遥感的发展概况及通用数据处理流程,着重分析了数据处理过程中的Hughes现象,指出可以通过对传统的处理方法进行适当的改进来有效地抑制Hughes现象,提高高光谱影像分类精度。  相似文献   

前散式和透射式能见度仪的综合观测试验及对比分析     

王惠颖  祖繁  袁成松  包云轩  吴泓  褚进华 《气象科学》2022,42(2):225-234

通过在野外观测基地和能见度计量检测实验室开展的前散式和透射式能见度仪对比观测试验,获取了能见度和其他气象与环境要素的同步观测数据,分析了不同大气环境条件下能见度测量值差异及其产生原因。结果表明：在能见度环境模拟舱内,两种能见度仪的测量值具有较好的一致性,但在自然环境中,两种能见度仪的测量值差异随能见度上升而快速增大。在不同天气现象出现时,前向散射仪与大气透射仪的测量值比值(VIS_FS/VIS_T)规律性变化明显,总体呈现随能见度上升而增大的趋势。无降水时,低湿情况下大气颗粒物吸收作用明显,透射能见度仪测量值远小于前散能见度仪测量值,两者均随PM_2.5质量浓度的增加而下降,且其差异也随之减小;高湿情况下大气颗粒物的散射作用在大气消光中占绝对优势,两种能见度仪测量值趋近。  相似文献   

Stochastic systems with cross-correlated Gaussian white noises     

王成玉  高云  宋玉敏  周鹏  杨海 《海洋学报(英文版)》2010,29(11)

This paper theoretically investigates three stochastic systems with cross-correlation Gaussian white noises. Both steady state properties of the stochastic nonlinear systems and the nonequilibrium transitions induced by the cross-correlated noises are studied. The stationary solutions of the Fokker-Planck equation for three specific examples are analysed. It is shown explicitly that the cross-correlation of white noises can induce nonequilibrium transitions.  相似文献   

融合物理理解与模糊逻辑的分类强对流客观短期预报系统:（2）表现评估     

田付友  郑永光  坚参扎西  吕新民  孙建华  黄玥  赤曲 《气象》2024,50(6):649-660

本文对分类强对流客观短期概率预报系统2022年6月13日强对流过程预报产品的表现进行分析,基于2022年的雷暴、短时强降水、雷暴大风及冰雹客观概率预报产品和可用的分类强对流监测实况资料,结合强对流预报业务中使用的空间检验方法和常用的确定性及概率性检验指标,对该短期预报系统提供的四类强对流天气客观概率预报产品进行了详细的性能评估。用于评估的预报资料是时段为2022年4月1日至9月30日每天08时(北京时)起报,96 h内逐12 h间隔的预报产品。预报个例分析显示,四类产品均可提前24 h指示需要关注的强对流天气区域。统计检验结果表明,短时强降水各方面性能最好,其次是雷暴,雷暴大风也有一定的可参考性。四类强对流天气预报产品均存在预报概率与实况频率相比偏高的过度预报问题。雷暴、短时强降水和雷暴大风预报产品均存在与预报覆盖时效有关的日变化。评估结果为预报模型和系统后续改进发展奠定了基础,为应用基于融合物理理解与模糊逻辑人工智能方法的分类强对流预报产品提供了有益参考。  相似文献   

乌苏33号石油探井喷涌现象的调查与分析   总被引：1，自引：1，他引：0  

史杰  高小其  黄新民  王在华 《内陆地震》2006,20(1):93-96

简要介绍了新疆乌苏33号石油探井的喷涌现象及调查情况,对该探井喷涌水样的测试结果与背景资料进行了对比,根据该地区的井水温梯度数据理论计算了喷涌水深度,并对调查结果进行了分析。  相似文献