简介：ＰｅｒｍａｆｒｏｓｔｉｎＴｉｂｅｔ￥ｂｙＬｉＳｈｕｄｅＣｈｉｎａｒａｎｋｓｔｈｉｒｄｉｎｔｈｅｗｏｒｌｄｉｎｔｅｒｍｓｏｆｃｏｕｎｔｒｉｅｓｗｉｔｈｅｘｔｅｎｓｉｖｅｔｅｒｒｉｔｏｒｙｓｕｂｊｅｃｔｔｏｐｅｒｍａｆｒｏｓｔ．Ｔｉｂｅｔ，ｗｈｉｃｈｓｉ...

简介：

简介：

简介：1.ObjectivesTheMoheBasininHeilongjiang,ChinahasaNEEthrustnappebelt,whichwasassembledbytherootzone,middlethrustzoneandthrustfront,north-southandnorth-eastnormalfaultswiththreetectonicactivitiesoftheMiddleJurassicto.Eocene,theMiocene,andtheEarlytoMiddlePleistocene.Themiddlethrustzoneandthrustfronthasalargenumberoffolds,thrustfaults,fracturesandglutenites,whicharethemajorstructuresofgashydrateaccumulationintheMoheBasin.

简介：1.ObjectivesAsthediscoveryofgashydrateinQilianMountainpermafrostin2008,themaincontrollingfactorsanddistributionofgashydratearenotclear.Thisrestrictsthefurtherprogressingashydratesurveyinthisarea.Hence,ChinaGeologicalSurveyerectedtheproject"ExplorationofgashydrateresourcesintheQilianMountainanditsadjacentareas"continuouslytobetterunderstandthegashydrateaccumulationintermsofgreatergashydratediscovery.

简介：PermafrostdegradationisprevalentontheQinghai-TibetPlateau.Thismayleadtochangesinwaterandheattransitioninsoilsandthusaffectthestructureandfunctionofecosystems.Inthispaper,usingthemeasureddataofalpinesteppeinWudaoliangassessedthemodelperformanceinsimulatingsoilfreezingandthawingprocesses.Comparisonofthesimulatedresultsbysimultaneousheatandwater(SHAW)modeltothemeasureddatashowedthatSHAWmodelperformedsatisfactorily.Basedonanalyzingthesimulatedandpredictedresults,twopointswereobtained:(1)freezingandthawingoftheactivelayerproceededbothfromthesoilsurfacedownward.Comparedwiththefreezingprocess,thethawingprocesswasslower.Thefreezingperiodpersistedinthesurfacelayer(4cmdepth)forabout5months;(2)inthenext50years,frozenperiodwouldbeshortenabout20daysinthetop100cmdepthwhilethethawingwouldstartearlier40daysthanpresent.Soilwaterstorageinthe0-60cmwoulddecreaseby22%averagely,especiallyfromJunetoAugustwhenthevegetationisatthedominatingwaterconsumedstage.Therefore,thiskindofpermafrostdegradationasactivelayerfreezingandthawingprocesseschangeswillreducesoilwatercontentandthusinfluencethoseecosystemsaboveit.