From precursors to prediction: a few recent cases from Greece   总被引：1，自引：0，他引：1  

P. Bernard  P. Pinettes  P. M. Hatzidimitriou  E. M. Scordilis  G. Veis  P. Milas 《Geophysical Journal International》1997,131(3):467-477

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Magma movements in Etna volcano associated with the major 1991–1993 lava eruption: evidence from gravity and deformation     

H. Rymer  J. Cassidy  C. A. Locke  J. B. Murray 《Bulletin of Volcanology》1995,57(6):451-461

The 1991–1993 eruption was probably the largest on Mt. Etna for 300 years. Since then the volcano has entered an unusually quiescent period. A comprehensive record of gravity and ground deformation changes presented here bracket this eruption and give valuable insight into magma movements before, during and after the eruption. The gravity and deformation changes observed before the eruption (1990–1991) record the intrusion of magma into the summit feeder and the SSE-trending fracture system which had recently been active in 1978, 1979, 1983 and 1989, creating the feeder dyke for the 1991–1993 eruption. In the summit region gravity changes between 1992 and 1993 (spanning the end of the eruption) reflect the withdrawal of magma from the conduit followed more recently (1993–1994) by the re-filling of magma in the conduit up to pre-eruption levels. In contrast, in the vicinity of the fracture zone, gravity has remained at the 1991–1992 level, indicating that no withdrawal has occurred here. Rather, magma has solidified in the fracture system and sealed it such that the 1993–1994 increase in magma level in the conduit was not accompanied by further intrusion into the flanks. Mass calculations suggest that a volume of at least 10⁷ m³ of magma has solidified within the southeastern flank of the volcano.  相似文献   

A fuzzy information processing system of seismic data     

Hidemi M. Ito  Akihiko Wakayama  Mitsuyuki Hoshiba  De-Yi Feng  Ming-Zhou Lin 《地震学报(英文版)》1993,6(4):813-821

We have developed a workstation-assisted information processing system. The system has three major functions: information retrieval from seismic data, detection of earthquake precursors, and graphical display of relevant results. Fuzziness is inevitably involved in these functions, an adequate treatment of which is vital. The system accepts instructions given by a successive choice of words in hierarchal structure, which is followed by a tune-up of the corresponding membership function. The degrees of fuzziness in the outputs are recognized visually, for example, by coloring. This contrivance together with dynamic data exchange among the above functions facilitates the operation of the system. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 399–406, 1993. This study is partly supported by a project “Fuzzy systems and their applications to human and natural sciences” of Science and Technology Agency.  相似文献   

Long-range earthquake forecasting based on a single predictor with clustering   总被引：1，自引：0，他引：1  

D. A. Rhoades  F. F. Evison 《Geophysical Journal International》1993,113(2):371-381

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Intermediate-term seismic precursors for some coupled subduction zones     

Renata Dmowska  Lucia C. Lovison 《Pure and Applied Geophysics》1988,126(2-4):643-664

The paper discusses model results and then reviews observational data concerning some aspects of the mechanics of mature seismic gaps in coupled subduction zones. The concern is with space-and time-varying stresses, as signalled by the presence and mechanisms of earthquakes in the outer-rise zones adjacent to main thrust areas of large subduction events, and down-dip from such areas, in the downgoing slab. Observations are shown to be consistent with the expectation that in mature seismic gaps, as a result of interplate boundary locking in presence of sustained gravitational driving forces, at least the deeper portions of the ocean plate in the outer-rise zones are under increased compression, and the downgoing slab is under increased tension. The observational data cover two cases of closed seismic gaps, namely the region of the Chilean Valparaiso earthquake of March 3, 1985, and the earthquake of October 4, 1983. Four other cases concern still to-be-closed gaps in northern Chile and along the coast of Guatemala, and also the Kurile Islands Trench gap and the northern New Hebrides gap. It is concluded that the intermediate-term precursor, consisting of a combination of compressional outer-rise earthquake(s) and tensional intermediate-depth, intra-plate events in the downgoing slab, which mechanically signals the latter part of the earthquake cycle, could be useful in evaluating the maturity, and hence great earthquake potential of a seismic gap.  相似文献   

A REGIONAL MODEL STUDY OF THE VARIATIONS AND DISTRIBUTIONS OF OZONE AND ITS PRECURSORS ON EASTERN ASIA AND WEST PACIFIC OCEAN REGIONS^*          下载免费PDF全文

Luo Chao  Zhou Xiuji 《Acta Meteorologica Sinica》1994,8(2):195-202

A simulated study of mechanism for variations and distributions of ozone and its precursors was made by using the three-dimensional regional Eulerian model.The results showed that the ozone production was controlled by NO_x,but there is a complicated nonlinear relation between them.The photochemical reactions controlled by solar radiation are the determinative factors affecting the variations of the surface ozone and its precursors.The relations of ozone and CO,PAN were studied.We compared the simulated and observed results during the PEM-WEST A in order to better understand the photochemical processes of ozone and its precursors.  相似文献   

Impact of cloud dynamics on tropospheric chemistry: Advances in modeling the interactions between microphysical and chemical processes     

P. J. Grégoire  N. Chaumerliac  E. C. Nickerson 《Journal of Atmospheric Chemistry》1994,18(3):247-266

A chemical module describing the tropospheric photochemistry of ozone precursors in both gaseous and aqueous phases for a remote continental atmosphere has been developed within the framework of a two-dimensional cloud model. Dynamical, microphysical and chemical processes are fully interacting in order to study the influence of clouds on ozone chemistry and to quantify the relative importance of the different processes on the budget and evolution of 12 chemical species. Whereas the concentrations of highly soluble species are strongly affected by evaporation and sedimentation, less soluble species are affected primarily by accretion. The model reproduces previously observed chemical phenomena such as the enrichment of formic acid at the top of the cloud.  相似文献   

从卫星观测数据提取地震前兆信息研究中的参考文献   总被引：1，自引：0，他引：1  

朱荣  杨冬梅  滕云田  王喜珍  吴琼 《国际地震动态》2007,(4):36-42

如何从卫星观测数据中提取地震前兆信息,是近年来的一个跨空间物理、地震学和板块构造学等交叉领域的研究焦点,本文收集整理了部分近年来国外学者在该方面研究的论文,以供相关领域研究者参考之用。  相似文献   

Crater Lake Temperature Changes of the 2005 Eruption of Santa Ana Volcano,El Salvador,Central America     

P. A. Hernández  N. M. Pérez  J. C. Varekamp  B. Henriquez  A. Hernández  J. Barrancos  E. Padrón  D. Calvo  G. Melián 《Pure and Applied Geophysics》2007,164(12):2507-2522

A sudden eruption at Santa Ana occurred on 1 October 2005, producing an ash-and-gas plume to a height in excess of 10 km above the volcano. Several days before, thermal infrared images of the crater provided precursory signals of the eruption. A significant increase in the extent and intensity of the fumarolic field inside the crater rim and of the surface temperature of the crater’s lake was observed. Changes in energy input was also estimated to explain the increase in lake temperature based on energy/mass balance calculations.  相似文献   

A reinterpretation of the precursory seismic b-value anomaly from fracture mechanics   总被引：1，自引：0，他引：1  

Ian G. Main  Philip G. Meredith  Colin Jones 《Geophysical Journal International》1989,96(1):131-138

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