The elusive mantle dynamic topography  

作　　者：Lijun LIU 

机构地区：[1]Department of Geology, University of Illinois at Urbana-Champaign

出　　处：《Science China Earth Sciences》2020年第2期312-314,共3页中国科学（地球科学英文版）

基　　金：the support of the National Science Foundation(Grant No.EAR-1554554);the Geo Thrust foundation at University of Illinois

摘　　要：The Earth's surface is characterized by a bi-modal distribution of topography,where continents on average are about 5 km higher than the ocean basins.This basic topographic property of the planet Earth could be intuitively explained by isostasy,in that the felsic・to・intermediate continental crust is thick(~40 km)and light(~2.8 g/cm3)while the mafic oceanic crust is thin(〜7 km)and dense(〜3 g/cm3).There are also large-scale topographic variations within continents and oceans,which could also be attributed to isostasy:the former is usually due to lateral variation in crustal thickness and the latter to different ages of the seafloor.Since it seems isostasy works just fine for most large-scale topographic features on Earth,why do we bother to further introduce dynamic topography?

关 键 词：TOPOGRAPHY topographic EARTH 

分 类 号：P227[天文地球—大地测量学与测量工程]