The Dynamics of Mid-Ocean Ridges

大洋中脊的动力学

• 批准号: 8911326
• 负责人: E M Parmentier
• 金额: $ 27.29万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1993-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8911326&HistoricalAwards=false
• 关键词: Dynamics; Mid; Ocean; Ridges

This project involves theoretical models aimed at under- standing mid-ocean ridge spreading centers and seafloor struc- ture. The principal investigators have developed 2-D time- dependent convection models that show that thermal and composi- tional density stratification of the mantle beneath spreading centers can lead to fluctuations in crustal thickness. They will now consider the effect of lower mantle viscosities and will specifically test whether high frequency variations in crustal thickness result that might explain the origin of abyssil hill lineations. They will construct 3-D models of magma flow beneath ridges, including flow in a ridge axis conduit to investigate the origin of the inside-corner bathymetric high at ridge-transform interestions and the asymmetry of the median valley near intersections. They will also explore a model for ridge segmentation and episodic spreading based on stresses and deformation in the lithosphere rather than convection in the mantle.

该项目涉及到针对大洋中脊扩展中心和海底结构的理论模型。主要研究人员已经建立了与时间相关的二维对流模型，该模型表明，扩张中心下方地幔的热和组成密度分层可以导致地壳厚度的波动。他们现在将考虑较低的地幔粘度的影响，并将专门测试地壳厚度的高频变化是否会导致可能解释深海丘陵线条起源的结果。他们将建立山脊下岩浆流动的三维模型，包括在山脊轴线管道中的流动，以调查山脊变换交汇点的内角测深高的来源以及交叉点附近中间山谷的不对称性。他们还将探索一种基于岩石圈中的应力和变形而不是地幔中的对流来划分山脊和幕式扩张的模型。