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，两次地震，7.0级和7.2级地震，使海地南部半岛的转换断层部分破裂。在这一项目期间，将对牙买加近海海域最近发生的地震进行海洋调查，以调查这些地震和同一地区以前的地震对构造和沉积的影响。沉积岩芯和高分辨率海底测绘将对活动断层进行成像，并对地震触发的沉积物进行采样。该项目的首要目标是将新的图像和样本与法国和牙买加的合作者在2012年收集的先前存在的数据进行比较。该项目的成果将有助于更好地了解断层运动和地震成因沉积物的特征，并提供对这一板块边界的复杂性和相关危险的洞察。一些关键的证据，如深海中悬浮的沉积物和重新活化的沉积物的同位素，都是短暂的。其他记录可能会因侵蚀而被抹去。正因为如此，该项目对时间非常敏感。研究生和本科生将在项目期间接受培训。大陆转换边界跨越人口稠密地区，就像2010年海地7.0级地震和2021年海地7.2级地震一样，这些边界的破裂可能会造成灾难性的破坏和生命损失。变换边界只能适应相对运动的轻微变化，即使是轻微的倾斜运动也能使它们变压或变张。这些边界可能演变成复杂的、往往约束较差的断层系统。恩里基洛-芭蕉园断裂(EPGF)是沿戈纳韦微板块南缘的左行东西向转换的主线。东部的EPGF形成了一个突出的山脊，形成了250公里长的海地南部半岛，植根于一条逆冲断层带上。2010年M7.0和2021年M7.2层序分别在该海脊的东段和西段断裂。这两个序列的特点都是主震几乎是横流的，余震主要向北部和西部推进。沿同一边界的两个地震序列中重复的不同断层之间的这种耦合强烈地表明，这些断层形成了一个单一的应变分割的跨压断层系统。这项研究的结果将限制这个系统是否延伸到牙买加航道，它是否在边界的海底部分产生类似的大地震，目前海地最近发生的地震，以及EPGF地震的沉积记录的保真度。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。