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岩浆岩地球上最著名的例子，那里的火山远离底层地幔中热区域以上的板边界形成。关于创建夏威夷帝国链和其他地方的火山的基本地球过程以及这些火山的巨大质量的基本过程仍然存在许多问题。 这项研究将涉及两次海上探险，以地震图像热点产生的岩浆外壳，并获得有关地壳体积，其组成，沿岛链的变化以及构造板如何响应火山的重量而变形的关键信息。除了获得对夏威夷皇家链形成的基本见解外，该研究还将有助于对夏威夷岛地区的地质灾害进行更全面的评估。 地震数据将在火山建筑物内以及周围的海洋地壳内形象，可用于评估地震，海啸和海底滑坡危险。该项目涉及强大的国家和国际合作。 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地震和海啸，响应于弯曲而产生的板变形。该计划是使用沿夏威夷 - 皇帝海山链的四个500公里长的样带，沿着四个500公里长的样带沿着15 km的海洋底部地震仪（海洋底部地震仪）获取一致的2D，深度渗透地震反射数据以及广角反射/折射数据。 这些样带的位置将涵盖岩浆安置和体积通量的时机的广泛变化，加载时岩石圈的年龄以及地形膨胀的存在/不存在。该样带足够长，可以捕获岩石圈对火山的弯曲反应，从而将其装载到弯曲凸起上。由广角地震数据创建的加工地震反射曲线和速度模型将限制岩浆添加到地壳中的岩浆和分布，以及在火山建筑物内和装载的海洋板中的断层。新的地震约束将与重力，磁性，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。这奖反映了NSF的立法任务，并被认为是通过基金会的智力综述和广泛的范围来评估的，并值得通过评估来进行评估。

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
• 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.