Collaborative Research: RAPID: Submarine record of disastrous earthquakes at a strain partitioned transpressional boundary: Haiti 2010 and 2021

合作研究：RAPID：应变分区压压边界灾难性地震的海底记录：海地 2010 年和 2021 年

• 批准号: 2201420
• 负责人: Sean Gulick
• 金额: $ 1.85万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-15 至 2022-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2201420&HistoricalAwards=false
• 关键词: Collaborative; Research; RAPID; Submarine; record

Two earthquakes, M7.0 and M7.2, ruptured sections of the transform fault along Haiti’s southern peninsula in 2010 and 2021. During this project a marine survey in Jamaican waters offshore the recent earthquakes will be conducted to investigate the tectonic and sedimentary effects of these and previous earthquakes in the same region. Sediment cores and high-resolution sub-bottom mapping will image active faults and sample earthquake-triggered sediment deposits. The overarching goal of the project is to compare the new images and samples with pre-existing data collected by the French in 2012 and by collaborators from Jamaica. Results of the project will help improve understanding of fault movement and the character of earthquake-generated sediment deposits and provide insight into the complexities of this plate boundary and the associated hazards. Some key evidence, such as sediment suspended in abyssal water and isotopes that date the remobilized sediments, are short-lived. Other records can be obliterated by erosion. Because of this, the project is time sensitive. Graduate and undergraduate students will be trained during the project.Continental transform boundaries cross heavily populated regions, and as in the M7.0 2010 and M7.2 2021 Haiti earthquakes, ruptures along these boundaries can cause catastrophic damage and loss of life. Transform boundaries can accommodate only modest changes in relative motion, even slightly oblique motion can make them transpressional or transtensional. These boundaries can evolve into complex, often poorly constrained, systems of faults. The Enriquillo-Plantain Garden Fault (EPGF) is the main strand of a sinistral E-W transform along the southern boundary of the Gonave microplate. The eastern EPGF traces a prominent ridge that forms the 250 km long southern peninsula of Haiti and is rooted on a belt of thrust faulting. The 2010 M7.0 & 2021 M7.2 sequences ruptured the eastern and western segments of this ridge, respectively. Both sequences feature mainshocks that were nearly transcurrent, and thrust after-shocks primarily to the north and west. Such coupling between distinct faults repeated in two earthquake sequences along the same boundary strongly suggests that these faults form a single strain-partitioned, transpressional fault system. The results of the study will constrain whether this system extends to the Jamaica Passage, whether it generates similar large earthquakes in the submarine part of the boundary now loaded by recent earthquakes in Haiti, and the fidelity of the sedimentary record for EPGF earthquakes.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.

2010 年和 2021 年发生的两次地震，M7.0 和 M7.2，使海地南部半岛的转换断层部分破裂。在该项目期间，将在最近发生的地震的牙买加水域进行海洋调查，以调查地震的构造和沉积影响。这些和同一地区以前的地震的沉积岩芯和高分辨率地下测绘将对活动断层进行成像，并对地震引发的沉积物进行采样。该项目的总体目标是将新图像和样本与法国人和牙买加在 2012 年收集的现有数据进行比较，该项目的结果将帮助合作者更好地了解断层运动以及地震产生的沉积物和沉积物的特征。一些关键证据，例如悬浮在深海中的沉积物和重新流动的沉积物的同位素，可以深入了解该板块边界的复杂性和相关危险，而其他记录可能会被抹去。因此，该项目具有时间敏感性，将在项目期间对研究生和本科生进行培训。大陆转变边界跨越人口密集地区，就像 2010 年 M7.0 和 2021 年海地 M7.2 地震一样，沿线发生破裂。这些边界可能会导致灾难性的破坏和生命损失。 变换边界只能适应相对运动的适度变化，即使是轻微的倾斜运动也会使它们产生压压或压张。恩里基洛-车前草花园断层 (EPGF) 是沿着戈纳夫微板块南部边界的左旋东西向变换的主线，东部 EPGF 沿着形成海地南部半岛 250 公里长的突出山脊。 2010 年 M7.0 和 2021 年 M7.2 序列分别使该山脊的东段和西段破裂。序列的特征是主震几乎是横流的，而余震主要是向北和向西强烈的逆冲，在同一边界的两个地震序列中重复出现的不同断层之间的这种耦合表明这些断层形成了一个单一的应变分区的压断层系统。研究结果将制约该系统是否延伸到牙买加海峡、是否在海地近期地震所造成的边界海底部分产生类似的大地震，以及EPGF沉积记录的保真度。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。