Collaborative Research: Active Rifting Along the Red Sea, Afar Triple Junction and Main Ethiopian Rift: Implications for Continental Rheolology and Lithosphere Dynamics

该项目是先前美国国家科学基金会边界线项目的延续和延伸，该项目利用空间大地测量技术，以及最重要的是全球定位系统观测，直接测量红海北部和中部的活动裂谷过程。该项目现已扩大到包括整个阿拉伯-努比亚-索马里板块相互作用区(阿法尔裂谷-裂谷-裂谷三重交汇处)。该项目涉及维护现有的连续全球定位系统站点(沙特阿拉伯、厄立特里亚、埃及)，重复对现有调查全球定位系统站点的观测，并在埃塞俄比亚、厄立特里亚、沙特阿拉伯和也门建立新的连续全球定位系统站点。正在沿Danakil区块(厄立特里亚)、穿过Danakil凹陷(厄立特里亚和埃塞俄比亚)以及埃塞俄比亚主要裂谷设置和测量新的GPS站点。所有工作都是与我们的东道国伙伴合作进行的。这项研究的目的是澄清与大陆岩石圈活动裂谷有关的地壳形变特征，特别是作为裂谷阶段(从大陆岩石圈裂谷到沿中央裂谷扩张的海洋)的作用。此外，在阿法尔的观测将有助于限制三重交界处以下的岩浆过程。其他相关的地质和地球物理观测将与大地测量结果相结合，以约束活动地壳形变的力学模型。总体而言，这项研究应加强对裂谷作用的机制、大陆岩石圈的流变性、岩浆侵入在驱动或局部化裂谷过程中的作用以及驱动板块构造的基本力学过程的理解。

This project is a continuation and extension of a prior NSF-MARGINS effort to use space geodetic techniques, and most importantly GPS observations, to measure directly active rifting processes within the northern and central Red Sea. The project is now extended to include the full Arabia-Nubia-Somalia zone of plate interaction (the Afar Rift-Rift-Rift Triple Junction). The project involves maintaining existing continuous GPS stations (Saudi Arabia, Eritrea, Egypt), repeat observations of existing survey GPS sites, and establishing new continuous GPS stations in Ethiopia, Eritrea, Saudi Arabia, and Yemen. New survey GPS sites are being set and surveyed along the Danakil Block (Eritrea), across the Danakil Depression (Eritrea and Ethiopia), and across the Main Ethiopian Rift. All work is in cooperation with our host-country partners.This research is aimed at clarifying the character of crustal deformation associated with active rifting of the continental lithosphere, particularly as a function of the stage of rifting (from rifting of the continental lithosphere to ocean spreading along the central rift valley). In addition, the observations in the Afar will help constrain magmatic processes beneath the Triple Junction. Other relevant geologic and geophysical observations will be integrated with the geodetic results to constrain models for the mechanics of active crustal deformation. Overall, this research should enhance understanding of the mechanics of rifting, the rheology of the continental lithosphere, the role of magmatic intrusion in driving or localizing rifting processes, and the fundamental mechanical processes responsible for driving plate tectonics.