Collaborative Research: Magnetotelluric Transect of a Modern Continent-Continent Collisional Orogen: The SouthernAlps, New Zealand

合作研究：现代大陆-大陆碰撞造山带的大地电磁断面：新西兰南阿尔卑斯山

• 批准号: 9725883
• 负责人: Philip Wannamaker
• 金额: $ 7.9万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2000-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725883&HistoricalAwards=false
• 关键词: Collaborative; Research; Magnetotelluric; Transect; Modern

9725883 Wannamaker On the South Island of New Zealand, convergence of the Pacific and Australian plates has given rise to a relatively narrow (~80 km wide) and less complex zone of active mountain building than in most other regions of the world. The dominant structural elements of the plate boundary are the Southern Alps where vertical movement and accompanying rates of erosion are among the highest in the world, and the Alpine Fault which has components of both strike- slip and dip-slip movement. The magnetotelluric work that willl be done under this project is part of a four year cooperative study of the South Island plate boundary involving U.S. and New Zealand scientists at USC, MIT, Woods Hole, UC Berkeley, Purdue, San Diego State, Utah, Institute for Geological and Nuclear Sciences (IGNS, NZ), Victoria University (NZ), and Otago (NZ). Support is being provided by both countries. The centerpiece of the project is a pair of multifaceted geophysical transects across the South Island including active source seismology, offshore multichannel and OBS data acquisition, passive seismology, petrophysics, magnetotellurics, gravity measurements, and surface geology. Experiments are aimed at delineating the crustal and upper mantle structure beneath the Southern Alps and adjacent regions. MT data collected so far has led to a high-quality magnetotelluric transect across the central South Island. The MT response of the interior of this orogen holds the exciting promise of understanding the thermal regime and rheology of the South Island at depth. The complete resistivity structure will provide essential bounds on crustal strain partitioning, metamorphism in the lower crust, relative deformation of the crust versus the mantle, compensation of the South Island uplift, and several other important processes. However, there presently exists a crucial gap in the MT coverage along the transect due to lack of land vehicle access across the principal region of u plift through the Main Divide of the South Island. The data collected in this project will close this gap in coverage with six-eight new MT soundings supported by helicopter transport. Personnel from the IGNS will participate in this effort and will provide manpower and logistical support. ***

9725883新西兰南岛的Wannamaker，太平洋和澳大利亚板块的融合已经引起了相对狭窄（宽约80公里），而活跃的山区建筑物的复杂区域比世界上大多数其他地区都不那么复杂。 板边界的主要结构元素是南阿尔卑斯山，其中垂直运动和伴随的侵蚀速率是世界上最高的，而高山断层具有踩踏滑移和倾斜运动的组成部分。 将在该项目下完成的磁性智能工作是对南岛板块边界进行的四年合作研究的一部分，该研究涉及美国和新西兰科学家在USC，麻省理工学院，伍兹霍尔，加州大学伯克利分校，加州大学伯克分校，普渡大学，圣地亚哥州，犹他州，犹他州，地质和核科学研究所，地质和核科学研究所（IGNS，NZ，NZ），Victoria（NZ）（NZ）（NZ）（NZ）和IT。 两国都提供了支持。 该项目的核心是整个南岛的一对多方面的地球物理样品，包括主动源地震学，海上多通道和观察数据采集，被动地震学，石油物理学，磁电磁性，重力测量和表面地质学。 实验旨在描述南部阿尔卑斯山和相邻区域下的地壳和上地幔结构。 到目前为止收集的MT数据导致了整个南部岛屿的高质量磁铁层面。 该基因内部内部的MT反应具有令人兴奋的希望，即深入了解南岛的热力状态和流变学。 完整的电阻率结构将为地壳应变分配，下地壳中的变质，地壳与地幔的相对变形，南岛的补偿以及其他几个重要过程提供基本界限。 但是，目前存在着沿着横断面的MT覆盖范围的关键差距，这是由于在U Plift的主要区域穿过南岛的主要鸿沟的主要区域缺乏陆地车辆的通道。 该项目收集的数据将通过直升机运输支持的六八名新MT声音来缩小覆盖范围。 来自IGN的人员将参与这项工作，并将提供人力和后勤支持。 ***