Scholarlink

<p>An exceptionally well-preserved outcrop of Holocene liquefaction structures in the Tortuguero Beach of southern-central Hispaniola has been investigated. We present a new high-resolution orthoimage mosaic, combined with fieldwork, sedimentary logging, structural analyses, and rock sampling for granulometric, grain-shape, and geochronological analysis to improve our understanding of the seismic hazard and the magnitude of the cyclic paleo-earthquakes occurred in this high seismically active region. Our results revealed three sedimentary sequences of deformed layers separated by undeformed sections. These metric-scale, episodic liquefaction structures resulted in an unusual negative density gradient in a coarsening upward stratified succession. Deformed layers form NNW-trending dome and basin elongated structures controlled by the present-day NE-directed regional shortening. Radiocarbon dating of the lower, intermediate, and upper sequences yielded ages (1σ) of 2332—2008, 1982—1803, and 1770—1530&#xa0;cal BP, respectively. Liquefaction structures were triggered by <i>M</i><sub><i>w</i></sub> &gt; 7 earthquakes likely occurring every 200&#xa0;years. Seismic hazard modeling establishes that the primary sources of earthquakes are the large-scale, strike-slip fault zones that accommodate the collision of the Beata Ridge with southern-central Hispaniola. These fault zones probably generated the 1751 <i>M</i><sub><i>w</i></sub> 7.5 Azua earthquake, and given the recurrence of such seismic events in southern Hispaniola, they could trigger future destructive earthquakes.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Soft-sediment deformation structures in Holocene coastal gravel deposits reveal two 1.8–2.0 ka old Mw > 7.0 earthquakes in southern-central Hispaniola

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年7月23日

查看全文
  • Francisco José Fernández,
  • Fernando Pérez Valera,
  • Javier Escuder-Viruete

摘要

An exceptionally well-preserved outcrop of Holocene liquefaction structures in the Tortuguero Beach of southern-central Hispaniola has been investigated. We present a new high-resolution orthoimage mosaic, combined with fieldwork, sedimentary logging, structural analyses, and rock sampling for granulometric, grain-shape, and geochronological analysis to improve our understanding of the seismic hazard and the magnitude of the cyclic paleo-earthquakes occurred in this high seismically active region. Our results revealed three sedimentary sequences of deformed layers separated by undeformed sections. These metric-scale, episodic liquefaction structures resulted in an unusual negative density gradient in a coarsening upward stratified succession. Deformed layers form NNW-trending dome and basin elongated structures controlled by the present-day NE-directed regional shortening. Radiocarbon dating of the lower, intermediate, and upper sequences yielded ages (1σ) of 2332—2008, 1982—1803, and 1770—1530 cal BP, respectively. Liquefaction structures were triggered by Mw > 7 earthquakes likely occurring every 200 years. Seismic hazard modeling establishes that the primary sources of earthquakes are the large-scale, strike-slip fault zones that accommodate the collision of the Beata Ridge with southern-central Hispaniola. These fault zones probably generated the 1751 Mw 7.5 Azua earthquake, and given the recurrence of such seismic events in southern Hispaniola, they could trigger future destructive earthquakes.