Collaborative Research: Towards quantifying eruptive timing and volcanic accretion on the Southern East Pacific Rise

合作研究：量化东南太平洋隆起的喷发时间和火山增生

• 批准号: 2128301
• 负责人: Ross Parnell-Turner
• 金额: $ 39.9万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2128301&HistoricalAwards=false
• 关键词: Collaborative; Research; Towards; quantifying; eruptive

Collaborative Research: Eruptive timing and volcanic accretion on the Southern East Pacific RiseSeventy percent of Earth’s surface is covered by ocean crust created by volcanoes at underwater mid-ocean ridges. It is important to accurately describe the size, shape, and frequency of submarine lava flows to understand how mid-ocean ridge volcanic systems work. A recent National Academies report identifies description of eruptive sizes and frequencies as one of the outstanding grand challenges in volcano science. However, distinguishing and accurately dating individual submarine lava flows remains challenging due to inadequate dating techniques, as well as considerable technical challenges associated with making observations and collecting samples from the seafloor. This project takes multiple approaches to measuring eruptive timing on the Southern East Pacific Rise (a mid-ocean ridge in the south Pacific). Data from self-driving underwater vehicles (AUV-autonomous underwater vehicle) will be combined with submersible observations and sample collection. Sample chemistry and magnetic signals help determine age and eruption frequency of surface flows, while the AUV data provide high-resolution mapping of the sea floor and additional information related to sub-surface lava flow distributions. The results will be combined into a model that can be and applied to other mid-ocean ridge settings. The proposed work will provide a comparison to the well-studied 9°N section of the northern East Pacific Rise, expanding the small number of intensively-studied ridge segments.The size, shape, and eruptive frequency of submarine lava flows are important first-order variables in our understanding of many mid-ocean ridge processes, including volcanic construction; magma recharge, flux, and storage; and the stability of hydrothermal systems and biological communities. A recent National Academies report identifies the quantification of eruptive sizes and frequencies as integral to one of the outstanding grand challenges in volcano science. However, distinguishing and accurately dating individual submarine flows in the geological record remains challenging due to inadequate radiometric techniques, as well as the considerable technical challenges associated with making observations and collecting samples from the seafloor. Further, for a process that is episodic, there is no commonly-accepted statistical framework for reporting or interpreting eruptive intervals. While considerable effort has gone into documenting eruptive history at 9°N on EPR and at Axial seamount on the Juan de Fuca Ridge, constraining a spatially and temporally variable global system requires significantly more data, and perhaps new approaches. The proposed work takes an integrated approach to quantifying eruptive timing on the Southern East Pacific Rise by combining AUV (autonomous underwater vehicle) mapping with HOV (human occupied vehicle) observations and sample collection. Near-bottom sidescan and bathymetric data will guide sampling locations and provide important interpretive context, as well as the possibility of calculating flow volumes. Geochemical data will be combined with temporal constraints provided by geomagnetic paleointensity to define eruptive clusters. Near-bottom magnetic anomaly data will be used to link the surface paleomagnetic data with a depth-integrated signal and provide important constraints on 3D statistical models of flow distributions, which are also constrained by estimates of layer 2A thickness from existing seismic reflection data. Combined, these methods will enable identification of flow units, quantifying eruptive frequency, and assessing accretionary processes. The resulting statistical model can be tested against and applied to other mid-ocean ridge settings. Further, the proposed work will provide a point of contrast to the well-studied 9°N segment and expand the small number of intensively-studied ridge segments.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.

协作研究：东太平洋南太平洋地区的爆发时间和火山积聚，地球表面的占地面积被海底在水下中海底山脊上产生的海皮覆盖。准确地描述海底熔岩流的大小，形状和频率，以了解中大海山脊火山系统的工作方式很重要。最近的一份国家科学院报告将喷发尺寸和频率的描述确定为火山科学中杰出的巨大挑战之一。但是，由于约会技术不足以及与进行观察和从海底收集样本相关的相关技术挑战，区分和准确约会各个海底熔岩流仍然受到挑战。该项目采用多种方法来测量东太平洋南部崛起（南太平洋中部山脊）的爆发时间。来自自动驾驶水下车辆（AUV自治的水下车辆）的数据将与潜水观测和样本收集相结合。样品化学和磁信号有助于确定表面流的年龄和喷发频率，而AUV数据则提供了海底的高分辨率映射以及与地下熔岩流量分布相关的其他信息。结果将合并为一个可以并应用于其他中海山脊设置的模型。拟议的工作将与东太平洋北部崛起的良好研究的9°N部分进行比较，扩大了少量的深入山脊段。海底熔岩流的大小，形状和喷发频率是我们对包括火山结构在内的许多中型山脊工艺的理解，包括我们对包括火山造成火山造成的中等海洋山脊的理解；岩浆充电，通量和存储；以及水热系统和生物群落的稳定性。最近的一份国家科学院的报告将喷发尺寸和频率的量化确定为火山科学中杰出的巨大挑战之一。然而，由于辐射技术不足以及与进行观察和从海底收集样本相关的考虑技术挑战，地质记录中的单个潜艇流程的区分和准确约会仍然受到挑战。此外，对于一个发作性的过程，没有用于报告或解释喷发间隔的普遍统计框架。尽管在EPR上的9°N和Juan de Fuca Ridge上的轴向海山的爆发历史上已经大大努力，但在空间和临时可变的全球系统上限制了更多的数据，需要更多的数据，甚至需要新的方法。拟议的工作采用了一种综合方法来通过将AUV（自动驾驶水下车辆）映射与HOV（人类占领的车辆）观测值和样品收集相结合，以量化东太平洋南部上升的爆发时间。近底侧扫描和测深数据将指导采样位置，并提供重要的解释环境，以及计算流量量的可能性。地球化学数据将与临时约束相结合，由地磁普拉斯特定义喷发簇。接近磁性异常数据将用于将表面古磁数据与深度集成信号联系起来，并对流动分布的3D统计模型提供重要约束，这也受到现有地震反射数据的2a层厚度的估计来限制。这些方法结合在一起，可以识别流量单位，量化喷发频率并评估增生过程。可以针对其他中海山脊设置进行测试并应用所得的统计模型。此外，拟议的工作将与经过良好研究的9°N细分市场形成鲜明对比，并扩大了少量研究的山脊细分市场。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来评估而被认为是珍贵的支持。

项目成果

Significance of Short‐Wavelength Magnetic Anomaly Low Along the East Pacific Rise Axis, 9°50′N

沿东太平洋海隆轴（9°50°N）的短波长低磁异常的意义

• DOI: 10.1029/2023gc010875
• 发表时间: 2023
• 期刊: Geosystems
• 作者: Berrios‐Rivera, Natalia;Gee, Jeffrey S.;Parnell‐Turner, Ross;Maher, Sarah;Wu, Jyun‐Nai;Fornari, Daniel;Tivey, Maurice;Marjanović, Milena;Barreyre, Thibaut;McDermott, Jill
• 通讯作者: McDermott, Jill