Composition, geometry, and emplacement dynamics of a large volcanic island landslide offshore M artinique: From volcano flank-collapse to seafloor sediment failure?
Composition, geometry, and emplacement dynamics of a large volcanic island landslide offshore M artinique: From volcano flank-collapse to seafloor sediment failure?
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马提尼克岛近海大型火山岛滑坡的组成、几何形状和就位动态：从火山侧面塌陷到海底沉积物破坏？
DOI：
10.1002/2015gc006034
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Brunet M
中科院分区：
文献类型：
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作者：
Brunet M
山体滑坡是火山岛附近的常见特征。在这篇文章中，我们研究了马提尼克火山岛周围的滑坡就位和动力学，这是基于对此类沉积物的首次科学钻探。佩尔萨梅火山的演化以三次主要的侧面崩塌为标志，这三次侧面崩塌使火山的西侧翼大部分被移走。地面崩塌量从2至25公里不等，碎片雪崩流入格林纳达盆地。高分辨率地震数据（AGUADOMAR‐1999、CARAVAL‐2002和GWADASEIS‐2009）与新的岩心相结合，这些岩心穿透了长达430米的三个海底滑坡沉积物，这些沉积物以前与空中侧壁崩塌有关（Site U1399、Site U1400、Site U1401, IODP Expedition 340, Joides resolution， 2012年3 - 4月）。这一结合了地球物理和岩心数据的方法，提高了人们对火山岛近海滑坡过程的理解。综合分析显示了一个大型海底滑坡沉积物，没有来自火山的碎片雪崩沉积物，包括长达300公里的海底沉积物，从海岸延伸70公里，面积为2100平方公里。我们的新数据表明，空中碎屑雪崩沉积进入海洋，但在潜艇侧翼底部停止。我们提出了一个新的模型来处理由火山侧面崩塌事件引发的海底沉积物破坏和滑坡传播机制，这些事件影响着Montagne pel<s:1> e火山。新发现的滑坡沉积物发生在地层较深的地方，这表明该岛近海大规模的质量浪费过程再次发生，因此，有必要更好地评估该地区相关的海啸危害。
Landslides are common features in the vicinity of volcanic islands. In this contribution, we investigate landslides emplacement and dynamics around the volcanic island of Martinique based on the first scientific drilling of such deposits. The evolution of the active Montagne Pelée volcano on this island has been marked by three major flank‐collapses that removed much of the western flank of the volcano. Subaerial collapse volumes vary from 2 to 25 km3and debris avalanches flowed into the Grenada Basin. High‐resolution seismic data (AGUADOMAR‐1999, CARAVAL‐2002, and GWADASEIS‐2009) is combined with new drill cores that penetrate up to 430 m through the three submarine landslide deposits previously associated to the aerial flank‐collapses (Site U1399, Site U1400, Site U1401, IODP Expedition 340, Joides Resolution, March–April 2012). This combined geophysical and core data provide an improved understanding of landslide processes offshore a volcanic island. The integrated analysis shows a large submarine landslide deposit, without debris avalanche deposits coming from the volcano, comprising up to 300 km3of remobilized seafloor sediment that extends for 70 km away from the coast and covers an area of 2100 km2. Our new data suggest that the aerial debris avalanche deposit enter the sea but stop at the base of submarine flank. We propose a new model dealing with seafloor sediment failures and landslide propagation mechanisms, triggered by volcanic flank‐collapse events affecting Montagne Pelée volcano. Newly recognized landslide deposits occur deeper in the stratigraphy, suggesting the recurrence of large‐scale mass‐wasting processes offshore the island and thus, the necessity to better assess the associated tsunami hazards in the region.