简介：AseismometerdataacquisitionunithasbeenusedintheChangpingseismicstationtorecordtheoutputofastrainmeter.Theoutputofastrainmeterwassampledatarateof100/secbyseismometeracquisitionfromtheoriginalrateof1perminute.Plentyofhighfrequencysampleddatawasrecorded.Theminutevaluecurvecalculatedfromtheseismometeracquisitionareconsistentwiththatoftheoriginaldatasampledbythestrainacquisitionsystem.Morecompletewaveformswererecordedwithahighersamplingrate,andseismicphaseparameterscalculatedbyusinghighersamplingratestrainseismicwavesarealsoinconsistencywiththeresultsofitspredecessors.SpectraofthestrainseismicwavesarecomparedwiththatofseismicwavesrecordedbyaseismometerintheShisanlingseismicstation,andtheirtrendsarealmostthesame.Besides,somelowerfrequencycomponentsstillexistinstrainseismicwaves.

简介：一、地震基本参数表1　地震基本参数表发震时间年月日时分秒震　中　位　置微　观宏　观东经北纬东经北纬参考地名震级(ＭＳ)震源深度(Ｋｍ)震中烈度　地震类型　1981122912261172°256°1171°256°连城丘家山3211Ⅴ小震群　　表中的宏观震中是根据现场调查所圈定的Ⅴ度线推测的,位于微观震中的南西方向约6公里的丘家山林场附近。震源深度则是依据经验公式计算结果推断的。二、地震烈度分布本次地震震中地处山区,强度小,地表破坏轻微,主要根据人的感觉及房屋的轻微损坏与否进行评定,划分出Ⅴ、Ⅳ度两区(见图8-1)。图8-1　1981年12月29日连城丘家山地震等震线图Ⅴ度区为极震区。Ⅴ度等震

简介：ＳｅｖｅｒａｌｑｕｅｓｔｉｏｎｓａｂｏｕｔｕｓｉｎｇｎａｔｉｏｎａｌｌｅｇａｌｍｅｔｒｏｌｏｇｉｃａｌｕｎｉｔｉｎｓｅｉｓｍｏｌｏｇｉｃａｌｐｅｒｉｏｄｉｃａｌｓＹｉ－ＪｕｎＦＥＮＧ（冯义钧），Ｘｕｅ－ＬｉａｎｇＬＩ（李学良）ａｎｄＣｈｅｎｇ－ＹｅＸ...

简介：Organicreefs,thetargetsofdeep-waterpetroleumexploration,developedwidelyinXishaarea.However,thereareconcealedigneousrocksundersea,towhichorganicrockshavenearlyequalwaveimpedance.Sotheigneousrockshavebecomeinterferenceforfutureexplorationbyhavingsimilarseismicreflectioncharacteristics.Yet,thedensityandmagnetismoforganicreefsareverydifferentfromigneousrocks.Ithasobviousadvantagestoidentifyorganicreefsandigneousrocksbygravityandmagneticdata.Atfirst,frequencydecompositionwasappliedtothefree-airgravityanomalyinXishaareatoobtainthe2Dsubdivisionofthegravityanomalyandmagneticanomalyintheverticaldirection.Thus,thedistributionofigneousrocksinthehorizontaldirectioncanbeacquiredaccordingtohigh-frequencyfield,low-frequencyfield,anditsphysicalproperties.Then,3Dforwardmodelingofgravitationalfieldwascarriedouttoestablishthedensitymodelofthisareabyreferencetophysicalpropertiesofrocksbasedonformerresearches.Furthermore,3Dinversionofgravityanomalybygeneticalgorithmmethodofthegraphicprocessingunit(GPU)parallelprocessinginXishatargetareawasapplied,and3Ddensitystructureofthisareawasobtained.Bythisway,wecanconfinetheigneousrockstothecertaindepthaccordingtothedensityoftheigneousrocks.Thefrequencydecompositionand3DinversionofgravityanomalybygeneticalgorithmmethodoftheGPUparallelprocessingprovedtobeausefulmethodforrecognizingigneousrockstoits3Dgeologicalposition.Soorganicreefsandigneousrockscanbeidentified,whichprovideaprescientinformationforfurtherexploration.