※ 引述《evil (溫柔)》之銘言： : 對了 順便請教一下關於地球板塊運動的機制為何 : 是不是熱的密度輕的物質向上升（中洋脊） : 然後向兩旁擴張 最後冷卻後密度變大 向下沈入地函中 : 於是有板塊移動 我所知道新的review是去年science上的一篇文章︰ Mantle Convection and Plate Tectonics: Toward an Integrated Physical and Chemical Theory 16 JUNE 2000 VOL 288 p. 2002-2007 作者︰Paul J. Tackley 摘要如下︰ Plate tectonics and convection of the solid, rocky mantle are responsible for transporting heat out of Earth. However, the physics of plate tectonics is poorly understood; other planets do not exhibit it. Recent seismic evidence for convection and mixing throughout the mantle seems at odds with the chemical composition of erupted magmas requiring the presence rapid progress on these two problems, with the emergence of the first self-consistent models of plate tectonics and mantle convection, along with new geochemical models that may be consistent with seismic and dynamical constraints on mantle structure. 該文後面接著還有一篇Bruce A. Buffett寫的 Earth's Core and the Geodynamo 摘要為︰ Earth's magnetic field is generated by solid motion in the liquid iron core. Details of how this occurs are now emerging from numerical simulations that achieve a self-sustaining magnetic field. Early results predict a dominant dipole field outside the core, and some models even reproduce magnetic reversals. The simulations also show how different patterns of flow can produce similar external fields. Efforts to distinguish between the various possibilities appeal to observations of the time-dependent behavior of the Teld. Important constraints will come from geological records of the magnetic field in the past. --

※ 發信站: 批踢踢實業坊(ptt.csie.ntu.edu.tw) ◆ From: ccsun57.cc.ntu.edu.tw