Collaborative Research: Seismic imaging of volcano construction, underplating and flexure along the Hawaiian-Emperor Seamount Chain

合作研究：夏威夷-皇帝海山链沿线火山构造、底侵和弯曲的地震成像

• 批准号: 1737245
• 负责人: Donna Shillington
• 金额: $ 52.26万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2020-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1737245&HistoricalAwards=false
• 关键词: Collaborative; Research; Seismic; imaging; volcano

The Hawaii-Emperor Seamount Chain is the most well-known example on Earth of hotspot magmatism, where volcanoes form far from plate boundaries above hot regions in the underlying mantle. Many questions remain about the fundamental earth processes that create the volcanoes of the Hawaii-Emperor chain and elsewhere, and how the enormous mass of these volcanos is supported by the rock material below them. This study will involve two seagoing expeditions to seismically image the magmatic crust created by the hotspot and obtain critical information about the crust's volume, its composition, how it varies along the island chain, and how the tectonic plate deforms in response to the weight of the volcanoes. In addition to gaining fundamental insight into the formation of the Hawaiian-Emperor chain, the study will also be beneficial to a more comprehensive assessment of geohazards for the Hawaiian island region. Seismic data will image faults within the volcanic edifice and in the surrounding oceanic crust that can be used to evaluate seismic, tsunami and submarine landslide hazards. The project involves strong national and international collaborations. The research cruises will provide excellent opportunities to involve students in data acquisition and analysis, and the results will be the basis for a large public outreach and education effort.The scientific objectives of the planned data acquisition and analysis of this project are to examine controls on magmatic addition along the Hawaiian-Emperor seamount chain, provide fundamental constraints on rheological properties of oceanic lithosphere, address the origin of the hotspot swell, and assess implications for earthquakes and tsunamis from plate deformation in response to flexure. The plan is to acquire coincident 2D, deep-penetration seismic reflection data as well as wide-angle reflection/refraction data using ocean bottom seismometers spaced at 15 km along four 500-km-long transects across the Hawaiian-Emperor seamount chain. The locations of these transects will encompass wide variations in the timing of magma emplacement and volume flux, the age of the lithosphere at the time of loading and the presence/absence of a topographic swell. The transects are sufficiently long to capture the flexural response of the lithosphere to volcano loading out to the flexural bulge. The processed seismic reflection profiles and velocity models created from wide-angle seismic data will constrain the volume and distribution of magmatic addition to the crust as well as faulting within the volcanic edifice and within the loaded oceanic plate. New seismic constraints will be combined with gravity, magnetic, bathymetric and geochemical data and used as the basis for flexural analysis and numerical modeling to gain fundamental new insights into crust and lithosphere dynamics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

夏威夷-皇帝海山链是地球上最著名的热点岩浆作用的例子，这里的火山形成于远离板块边界的地幔热区域之上。关于形成夏威夷-皇帝链和其他地方火山的基本地球过程，以及这些火山的巨大质量如何由它们下面的岩石材料支撑的问题，仍然存在许多问题。 这项研究将涉及两次海上探险，对热点产生的岩浆地壳进行地震成像，并获得有关地壳体积、成分、地壳沿岛链如何变化以及构造板块如何因地壳重量而变形的关键信息。火山。除了获得对夏威夷-皇帝链形成的基本了解外，这项研究还将有利于对夏威夷岛屿地区的地质灾害进行更全面的评估。 地震数据将对火山大厦内和周围洋壳内的断层进行成像，可用于评估地震、海啸和海底滑坡灾害。该项目涉及强有力的国内和国际合作。研究航行将为学生提供极好的机会参与数据采集和分析，其结果将成为大型公共宣传和教育工作的基础。该项目计划数据采集和分析的科学目标是检查对沿着夏威夷-皇帝海山链的岩浆添加，为海洋岩石圈的流变特性提供了基本约束，解决了热点膨胀的起源，并评估了板块变形对弯曲的影响对地震和海啸的影响。该计划是使用沿夏威夷-皇帝海山链的四个 500 公里长横断面间隔 15 公里的海底地震仪采集一致的二维、深穿透地震反射数据以及广角反射/折射数据。 这些样线的位置将包含岩浆侵位和体积通量的时间、加载时岩石圈的年龄以及地形隆起的存在/不存在等方面的广泛变化。横断面足够长，足以捕捉岩石圈对火山负载到弯曲隆起的弯曲响应。根据广角地震数据创建的经过处理的地震反射剖面和速度模型将限制地壳中岩浆的体积和分布以及火山大厦和加载的海洋板块内的断层。新的地震约束将与重力、磁力、测深和地球化学数据相结合，并用作弯曲分析和数值建模的基础，以获得对地壳和岩石圈动力学的基本新见解。该奖项反映了 NSF 的法定使命，并被认为值得支持通过使用基金会的智力优点和更广泛的影响审查标准进行评估。

项目成果

Seismic Structure, Gravity Anomalies and Flexure Along the Emperor Seamount Chain

皇帝海山链沿线的地震结构、重力异常和弯曲

• DOI: 10.1029/2020jb021109
• 发表时间: 2021-03
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Watts, A. B.;Grevemeyer, I.;Shillington, D. J.;Dunn, R. A.;Boston, B.;Gómez de la Peña, L.
• 通讯作者: Gómez de la Peña, L.