学科分类
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2 个结果
  • 简介:AbundantevidencesofhighersealevelsfromJiangsuandFujiancoastshaveprovedamarinetransgressioneventduring30–40kaBP,suggestingthattherewasastagewithhighsealevelandawarmclimatewhenicesheetsshrankintheNorthernHemisphere.Thedurationof30–40kaBPspannedaperiodinthelateMarineIsotopeStage3(MIS3)andwasinnatureaninterstadialepochduringtheLastGlacialperiodoftheQuaternary.Differentfromtheglacialperiodwithacoldclimate,thismarinetransgressionconsideredasapenultimatehighersealevelduringtheQuaternaryremainsapuzzlethatwhytheevidenceiscontrarytotheQuaternaryglacialtheory.Itisimportanttounderstandsealevelrisefortheseareassensitivelyrespondingtotheglobalchangesinthefuture.Torecognizethekeyissuesonsealevelchanges,theeustaticsealevel(H_S)wasdefinedastheglaciation-climateforcedsealevels,andtherelativesealevelchange(H_R)wasdefinedasthatasealevelrecordwaspreservedinsedimentthatexperiencedmultiplesecondaryactionsoflandandseaeffects.Onthebasisasdefinedabove,weconstructedmulti-levelmodelsofclimate-drivenglacio-eustaticchangesandland-seasystems.Byintegratingdatasetsfromeightboreholecoresandprescribingtheboundaryconditions,wesimulatedthechangesofHSandHRintheEastChinaSeaandsouthernYellowSeaareasinthelateMIS3.Themarinetransgressionstratafromtheboreholecoredatawasidentifiedatca.30mbelowpresentsealevelasaresultofthecollectiveinfluenceoficemeltingwater,neotectonicsubsidence,sedimentcompactionandterrestrialsedimentfillingsinceca.35kaago,whereasthesimulatedrelativesea-levelsturnedouttobe–26.3––29.9ma.s.l.Thesmallerrorinvolvedinthesimulationresultsof±(2.5–4.5)mdemonstratedthecredibilityoftheresults.OurresultsindicatedthatsealevelchangeinthelateMIS3wasdominatedbyglacialeffects,inwhichtheeustaticsea-levelwasbetween–19.2�

  • 标签: 南黄海地区 动态模拟 MIS 东海岸 越轨行为 中国
  • 简介:基于广州及深圳海岛海岸带区域的1:2000航空摄影测量项目,对比分析A3航摄仪在有、无地面像控点情况下的空中三角测量精度.结果表明,在无地面像控点的情况下,A3仍可满足海岛海岸带区域大比例尺成图的精度要求,且航摄效率高、成图周期短.本研究可为A3在海岛海岸带区域的应用提供参考.

  • 标签: 航空摄影 A3航摄仪 空中三角测量 海岛海岸带 数字正射影像