Gravity of Pito Deep: A Propagating Rift Tip on the Easter Microplate

皮托深渊的重力：复活节微板上传播的裂谷尖端

• 批准号: 9000435
• 负责人: Fernando Martinez
• 金额: $ 5.21万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 1991-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9000435&HistoricalAwards=false
• 关键词: Gravity; Pito; Deep; Propagating; Rift

Detailed surveys of a propagating spreading center along the East Pacific Rise (EPR) at 95.5W show that plate boundary configurations, rather than being static, can undergo complex geometric changes. Models based on either dynamic, kinematic or mechanical processes within the crust and mantle have been developed to explain these intricacies. However, the applicability of these models to other propagating systems has yet to be established, and Dr. Martinez will conduct an evaluation of the various models by examining previously acquired data from the Pito Deep area at 23S on the EPR. This area contrasts with the 95.5 propagator in severval ways: the Pito Deep propagator is advancing along a broad "front", not a "tip" as at 95.5N; local topography varies enormously from a regional mean of 3500m to a local depression of 5980m; and complex topography north of the rift mimics the fabric and trend of the rift zone, suggesting an unusually strong coupling across this region. Any or all of these constrasts may be explained by the fact that Pito Deep is offset along a long (300 km vs 30 km for the feature at 95.5N) transform and intrudes into unusually old lithosphere (3 my vs 1 my). Dr. Martinez will grid existing SeaMARCII bathymetry and construct a terrain-corrected Bouger anomaly map of the Pito Deep region. With this and with assumptions of the nature of isostatic compensation he will calculate residual gravity anomalies to identify anomalies due to Moho topography. Anomalies that remain after this procedure will form the basis for testing among the competing models that require either: 1) viscous flow in the asthenosphere, 2) thermal effects due to dike intrusion, or 3) mechanical implications of a lithosphere of finite strength.

对沿着东部传播传播中心的详细调查 95.5W的太平洋隆起（EPR）显示板块边界 配置，而不是静态的，可以经历复杂的 几何变化 基于动力学、运动学或 地壳和地幔内部的机械过程 来解释这些复杂的现象 但 这些模型对其他传播系统的适用性 尚未建立，马丁内斯博士将进行一次 通过检查以前获得的各种模型的评估 来自EPR上23 S处的Pito Deep区域的数据。 这一领域 在几个方面与95.5传播者形成对比：Pito 深层传播者是沿着沿着宽阔的“战线”前进的，而不是一个“尖端” 在95.5N;当地地形变化很大，从一个区域 平均3500米至5980米的局部洼地; 裂谷北部的地形模拟了 裂谷带，这表明了一个异常强烈的耦合， 地区 任何或所有这些约束可以解释为 事实上，皮托深是抵消沿着长（300公里与30公里， 在95.5N的特征）转变并侵入异常古老的 岩石圈（3米对1米）。 马丁内斯博士会在你的办公室里 SeaMARCII水深测量和构造地形校正的Bouger Pito Deep地区的异常地图。 有了这个， 假设均衡补偿的性质，他将 计算剩余重力异常，以确定由于 莫霍面地形 在此过程之后仍然存在的异常将 形成了在竞争车型之间进行测试的基础， 需要：1）软流圈中的粘性流，2）热 由于堤坝入侵的影响，或3）机械影响的 强度有限的岩石圈