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1.
Studyonthepatternandmodeofverticalcrustaldeformationduringtheseismogenicprocessofintraplatestrongearthquakes杨国华,桂昆长,巩曰沐,杨春花,韩...  相似文献   

2.
FieldofverticalcrustaldeformationinNorthChinaandthefeatureofitsdynamicevolution王若柏,洪汉净,许忠淮,耿世昌,孙东平,韩月萍Ruo-BaiWANG;Han-JingHON...  相似文献   

3.
What is a credible seismic precursor in observation of deformation? A real seismic precursor ought to be resulted from the variations in the earth strain and stress. The deformation observation can provide the information during earthquake gestation and occurrence period for us. Usually the seismic precursors can be divided into field and epicentral region precursors. The precursor information is very useful for seismic prediction from epicentral region or near epicentral region. Micro-deform…  相似文献   

4.
ThemutationsequenceofearthresistivityandearthquakesXin-HengLIU(刘心恒)andYun-ShengZHOU(周郧生)(SeismologicalBureauofYunnanProvince,...  相似文献   

5.
Theoriginofthecrustalconductivelayerandtheconductivityofsupercriticalbrine(Ⅱ)CHANG-FANGXU(徐常芳)InstituteofGeology,StateSeismo...  相似文献   

6.
In this paper, progress in strain study of blocks and faults by GPS data are discussed, and the concept that active structures between blocks are the main body of crustal strain is clarified. By energy transfer principle of elastic mechanics, the relation between strain around faults and tectonic force on fault surfaces is set up and main body element model of crustal strain is constructed. Finally, the relation between mechanical evolution of model and seismogenic process of Kunlun earthquake (Ms=8.1) is discussed by continuous GPS data of datum stations. The result suggests that the relatively relaxed change under background of strong compressing and shearing may help to trigger moderate-strong earthquakes.  相似文献   

7.
Thespatialtemporalevolutioncharacteristicsoftheload/unloadresponseratio(LURR)anditsimplicationsforpredictingthethreeelementso...  相似文献   

8.
Seismogenic mechanism of the Lancang and Gengma earthquakes   总被引:1,自引:0,他引:1  
Seismogenic mechanism of the Lancang and Gengma earthquakes(俞维贤)(周瑞琦)(候学英)(周光全)SeismogenicmechanismoftheLancangandGengmaearth...  相似文献   

9.
ThehistoricevolutionofZhouyuanandthenewestactivityofthegreatWeiRiverfaultXue-FaYI(易学发)andYa-QinSHI(师亚芹)(SeimologicalBureauofS...  相似文献   

10.
ThepatterncharacteristicsofthetendencyvariationsofearthresistivityanditsrelationtoearthquakesHe-YunZHAO(赵和云)(EarthquakeResear...  相似文献   

11.
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Therelationshipsbetwenearthquakesandpositionsofthesunandmoon(Ⅱ)——Sometemporalcharacteristicsoftheaftershocksequencesofstronge...  相似文献   

13.
IntroductionUntilnow,manyobservationsandstudiesshowthatinacertainareasandduringacertainperiodmajorearthquakesfrequentlyocured...  相似文献   

14.
Pyroclastic deposits from the 1982–1983 eruption of Galunggung volcano (Java, Indonesia) reflect preeruptive magmatic evolution which is of interest because of: (1) its duration of nine months, compared to a few hours or days for most historical eruptions; (2) the diversity of eruptive styles, from ash and scoria flows to phreatomagmatic explosions, and to the strombolian activity that marked the end of the eruption; and (3) the progressive variation in chemical composition with time, from andesite (58 wt.% SiO2) to high-Mg basalt (47 wt.% SiO2). The 1982–1983 Galunggung basalts are rather primitive: 10 to 12 wt% MgO, 180 to 200 ppm Ni and 550 to 700 ppm Cr. Despite the presence of about 40% phenocrysts, they may represent the most primitive basalts recognized in western Java. Basalts contain phenocrysts of olivine (Fo90-80), diopside-salite, and plagioclase (An95-75). Andesites contain plagioclase (An80–60), augite, hypersthene (En67-64), and titanomagnetite. The distribution of mineral compositions in each petrographic type is nearly unimodal, although scarce plagioclase and olivine xenocrysts have been observed. Abundance of gabbroic cumulates associated with the pyroclastic flows and evolution of mineral compositions from high-Mg basalts to andesites support crystal fractionation as the main differentiation mechanism, although magma mixing of basaltic andesite and andesite cannot be excluded. Major and trace element trends, which display rough decreases of MgO, CaO, Ni, Cr with increasing degree of differentiation and also linear positive correlations of hygromagmaphile elements, are compatible with both processes. However, some discrepancies are observed between major and trace element modelling, which may be explained to some extent by the influence of in situ crystallization and/or magma mixing. The constancy of 143Nd/144Nd (0.51286±3), 230Th/232Th (0.65±0.02), Th/U (4.08±0.07) ratios, and to a lesser extent 18O values (+5.8 to +6.4 % SMOW) and 87Sr/86Sr ratios (0.70440 to 0.70468) is compatible with a magmatic evolution through fractional crystallization without significant crustal contamination. Nevertheless low-18O and high 87Sr/86Sr values in basaltic andesites may be due to the introduction of meteoric fluids into the Galunggung magma.  相似文献   

15.
New databases motivate improvements and extensions of the catalogue by Grünthal and Wahlström (J Seismol 7:507–531, 2003a) – G&;W03 – of earthquakes in central, northern, and northwestern Europe with M w?≥?3.50. Data from over 30 regional catalogues, the International Seismological Centre and U.S. National Earthquake Information Center bulletins for the NE Atlantic Ocean, and many special studies were analysed, largely along the lines of the previous study. Non-tectonic, non-seismic, and non-existing as well as duplicate events were identified and removed according to our current stage of knowledge. If not given by the original source, the moment magnitude, M w, was calculated for each event with a specified epicentral location and a given strength measure (i.e., an original magnitude of any type or, for onshore events only, an intensity). The calculations follow transformation relations derived in the present or in our previous study. The investigated area is subdivided into 22 polygons, in each of which one or more local catalogues, supplemented by data from special studies, are used. If more than one catalogue lists an event, one entry was selected according to a priority algorithm specific for each polygon. If the selected catalogue entry contains more than one strength type, one was selected for the M w calculation according to another priority scheme. The final catalogue, CENEC, is confined to the time period 1000–2004 and magnitudes M w?≥?3.50. This is an extension of the time period covered by G&;W03 (1300–1993). The number of events has increased from about 5,000 to about 8,000. For each entry, available information on the date, time, location (including focal depth), intensity I 0, magnitude M w, and source (i.e., the local catalogue or special study) are given. The strength type and value from which M w was calculated are also indicated. The catalogue is available on the website of the GFZ German Research Centre of Geosciences.  相似文献   

16.
Catalogue of earthquakes (September-November,1993)(陈培善)Catalogueofearthquakes(September-November,1993)¥Pei-ShanCHEN(Institute...  相似文献   

17.
18.
Catalogueofearthquakes(March-May,1995)Pei-ShanCHEN(陈培善)(InstituteofGeophysics,StateSeismologicalBureau,Beijing100081,China)Il...  相似文献   

19.
Catalogueofearthquakes(September-November,1994)陈培善Pei-ShanCHEN(InstituteofGeophysics,StateSeismologicalBureau,Beijing100081,C...  相似文献   

20.
Catalogueofearthquakes(June-August,1993)Pei-ShanCHEN(陈培善)(InstituteofGeophysics,StateSeismologicalBureau,Beijing100081,China)...  相似文献   

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