Collaborative Research: Seismic Investigation of Deep Continental Structure in Tanzania, East Africa

9304555兰斯顿 这项研究的目的是利用PASSCAL阵列的被动震源地震记录和重力数据分析，研究坦桑尼亚的地壳和上地幔结构。 在古大陆区域之下存在的厚的亏损地幔岩石圈是深部大陆结构模式的基础。 这个模型的一个主要主张是，在一个一般移动的和不太稳定的岩石圈内，具有岩石圈龙骨的电子核是真正的构造稳定岛。 这项工作将通过研究东非一个构造活动活跃地区岩石圈的稳定性来检验这种大陆深部结构模型。 在东非的岩石圈（坦桑尼亚东部）已受到新生代伸展构造作用，提供了一个独特的机会，以确定是否深的岩石圈结构可以“生存”的伸展事件，热和机械破坏相邻的年轻岩石圈。 美国的类似构造是现今地震活动的场所，这些结果将对发震构造的机制产生影响。 这项研究是国家地震减灾计划的一个组成部分。 ***

9304555 Langston This research is to conduct a study of the crustal and upper mantle structure in Tanzania by means of passive-source seismic recording with the PASSCAL array and by means of analysis of gravity data. The existence of thick, depleted mantle lithosphere beneath ancient continental regions forms the basis of the model for deep continental structure. A principal assertion of this model is that cratonic nuclei with their lithospheric keels are true islands of tectonic stability within a generally mobile and less stable lithosphere. This work will test this model of deep continental structure by examining the stability of cratonic lithosphere in an area of active tectonism, East Africa. The cratonic lithosphere in East Africa (the Tanzania Craton) has been subjected to Cenozoic extensional tectonism, providing a unique opportunity to determine if deep cratonic structure can "survive" an extensional event which has thermally and mechanically disrupted adjacent younger lithosphere. Similar structures in the U.S. are the sites of current seismic activity and these results will bear on the mechanism of the earthquake generating structure. This research is a component of the National Earthquake Hazard Reduction Program. ***