Collaborative Research: The Thermal State of 20-25 Ma Lithosphere Subducting at the Costa Rica Margin, Implications for Hydrogeology, Fluxes, and the Seismogenic Zone

合作研究：哥斯达黎加边缘 20-25 Ma 岩石圈俯冲的热状态、对水文地质、通量和地震带的影响

• 批准号: 0001941
• 负责人: Carol Stein
• 金额: $ 9.96万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-10-01 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0001941&HistoricalAwards=false
• 关键词: Collaborative; Research; Thermal; State; 20

Fisher 0001892Wheat 0002031Harris 0001944Stein 0001941Recommended project is for a multidisciplinary investigation of the thermal state of the subducting lithosphere offshore of the Costa Rica margin. Heat flow measurements will be undertaken in two cruises covering oceanic lithosphere portions offshore of the Nicoya Peninsula that differ in makeup and tectonic style, with the northern portion formed at the East Pacific Rise and the southern portion, separated by an abrupt change in relief, formed at the Cocos-Nazca spreading center. These measurements will be accompanied by seismic and swath bathymmetric study, as well as a coring program that will examine changes in porewater chemistry associated with fluid flow in the sediments overlying the crust. These field programs will be accompanied by two numerical modeling exercises that will examine the thermal state of the subduction zone as these two portions of lithosphere subduct. The goals will be to determine the comparative thermal state of the subducting lithosphere in these regions, the associated heat and fluid fluxes responsible for the subducting slab thermal states, and how these variable affect subduction zone processes, including chemical flux rates.

Fisher 0001892Wheat 0002031Harris 0001944Stein 0001941 推荐项目是对哥斯达黎加边缘近海俯冲岩石圈的热状态进行多学科研究。 热流测量将在两次航行中进行，覆盖尼科亚半岛近海的海洋岩石圈部分，这些部分的构成和构造风格不同，北部部分形成于东太平洋海隆，南部部分则被地势突变所分隔，形成于科科斯-纳斯卡扩张中心。 这些测量将伴随着地震和条带测深研究，以及一个取心计划，该计划将检查与地壳上沉积物中的流体流动相关的孔隙水化学变化。 这些现场计划将伴随两个数值模拟练习，将检查俯冲带作为岩石圈俯冲的这两个部分的热状态。 目标将是确定这些区域俯冲岩石圈的相对热状态、导致俯冲板片热状态的相关热和流体通量，以及这些变量如何影响俯冲带过程，包括化学通量率。