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南極氷床変動と氷河性地殻均衡
奥野, 淳一
Permalink : http://hdl.handle.net/2115/70336
JaLCDOI : 10.14943/lowtemsci.76.205
KEYWORDS : アイソスタシー;氷床変動;海水準変動;地球内部粘性構造;Isostasy;Ice sheet change;Sea-level change;Mantle viscosity
Abstract
気候変動が引き起こす氷床変動とそれに伴う海水量変動は，地球表層における質量分布を変化させ，固体地球を変形させる．これは粘弾性的性質をもつ地球がアイソスタシーを回復しようとする変動であり，多様な時空間スケールの観測より検知されている．海水準変動や地殻変動，および重力場変動といった測地学的，地形・地質学的な観測値は，時間・空間スケールの異なる固体地球の変形が重畳していることから，観測値より氷床変動や地球内部構造を推定するためには，アイソスタシーの原理に基づいた数値モデリングが必要不可欠である．ここでは，氷河性地殻均衡（Glacial IsostaticAdjustment）の数値モデリングに基づいて氷床変動・地球内部構造を推定した研究について紹介する．
Ice sheet and sea water act as surface mass loads on the solid Earth. Variations of ice sheet and sea-level in late Quaternary induce the viscoelastic deformation of the Earth, and these deformations are detected by geodetic and geographical observations in both polar regions. To estimate the ice sheet change and viscosity structure of the Earth’s interior based on these observations, we need to apply the numerical modelling described by the Glacial Isostatic Adjustment (GIA) theory. Here, we review the inferences of ice sheet change and the viscosity of the Earth’s mantle based on the GIA modelling.
Ice sheet and sea water act as surface mass loads on the solid Earth. Variations of ice sheet and sea-level in late Quaternary induce the viscoelastic deformation of the Earth, and these deformations are detected by geodetic and geographical observations in both polar regions. To estimate the ice sheet change and viscosity structure of the Earth’s interior based on these observations, we need to apply the numerical modelling described by the Glacial Isostatic Adjustment (GIA) theory. Here, we review the inferences of ice sheet change and the viscosity of the Earth’s mantle based on the GIA modelling.
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