Collaborative Research: Testing models of magmatic and hydrothermal segmentation: A 3-D seismic tomography experiment at the Endeavour Ridge

合作研究：测试岩浆和热液分割模型：奋进山脊的 3D 地震层析成像实验

• 批准号: 0454700
• 负责人: William Wilcock
• 金额: $ 34.17万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0454700&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; models; magmatic

Competing models for controls on the segmentation and intensity of ridge crest processes are at odds on the scale of mantle and crustal magmatic segmentation, the distribution of hydrothermal venting with respect to a volcanic segment and the properties of the thermal boundary layer that transports energy between the magmatic and hydrothermal systems. The recent discovery of an axial magma chamber (AMC) reflector beneath the Endeavour segment of the Juan de Fuca ridge, as well as systematic along axis changes in seafloor depth, ridge crest morphology and hydrothermal venting provide an ideal target for testing conflicting hypotheses. The scientific objectives of this project are to: (1) Determine if the segmentation and intensity of the magma-hydrothermal systems at the Endeavour ridge are related to magma supply or to the magma plumbing between the mantle and crust, and (2) Constrain the thermal and magmatic structure underlying the Endeavour hydrothermal system in order to understand the patterns of energy transfer. An active source seismic tomography experiment, using an array of 64 three-component ocean-bottom seismometers, will image the 3-D seismic structure of the crust and topmost mantle along an 80-km-long section of the Endeavour ridge. The experiment will image four targets: (1) crustal thickness variations within 25 km of the axial high (0 to 900 kyr); (2) the 2-D (i.e., map view) structure of the uppermost mantle beneath the spreading axis; (3) the 3-D structure of the crustal magmatic system and (4) the detailed 3-D, shallow crustal thermal structure beneath the Endeavour vent field. The results of imaging will define the recent history of magma supply, the pattern of melt delivery from the mantle to the crust and the structure and segmentation of the subseafloor magmatic and hydrothermal systems. These measurements are essential to testing critically competing hypotheses for what regulates the intensity of ridge crest magmatic and hydrothermal processes.

竞争模型的控制模型在地幔和地壳岩浆分割的规模上，脊峰流程的分割和强度矛盾，相对于火山段的热液排气的分布以及在岩浆和水热系统之间运输能量的热段特性。 最近发现了Juan de Fuca Ridge的努力段下方的轴向岩浆室（AMC）反射器，以及沿轴沿着海底深度的系统变化，Ridge Crest形态和水热通风孔的系统变化为测试相互矛盾的假设提供了理想的目标。 该项目的科学目的是：（1）确定努力脊的岩浆 - 热热系统的分割和强度是否与岩浆供应或地幔和地壳之间的岩浆管道有关，（2）限制了能源能量的良好热热系统下的热热和岩浆结构，以了解能源的模式。 使用64个三组分海底地震仪的阵列的主动源地震断层扫描实验将对地壳的3-D地震结构和最高地幔沿着80公里长的努力脊组成。 该实验将成像四个目标：（1）轴向高25 km（0至900 kyr）以内的地壳厚度变化； （2）在扩展轴下的最高地幔的2-D（即地图视图）结构； （3）地壳岩浆系统的3-D结构，以及（4）努力排气场下方的详细3-D，浅层地壳的热结构。 成像的结果将定义岩浆供应的近期历史，即从地幔到地壳的熔体递送模式，结构和分割的岩层岩浆和水热系统的结构和分割。 这些测量对于检验与脊crest岩浆和热液过程的强度的严格竞争假设至关重要。