The relationship between eruptive activity, flank collapse, and sea level at volcanic islands: A long-term (>1 Ma) record offshore Montserrat, Lesser Antilles
The relationship between eruptive activity, flank collapse, and sea level at volcanic islands: A long-term (>1 Ma) record offshore Montserrat, Lesser Antilles
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火山岛喷发活动、侧翼塌陷和海平面之间的关系：小安的列斯群岛蒙特塞拉特岛近海的长期（>1 Ma）记录
DOI：
10.1002/2015gc006053
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发表时间：
2016
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影响因子：
--
通讯作者：
Coussens M
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文献类型：
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作者：
Coussens M
在综合大洋钻探计划第340次考察期间在蒙特塞拉特东南部钻探的U1395 B孔提供了一个长时间（>1 Ma）的喷发和物质消耗事件（>130个离散事件）的详细记录。这一记录可用于探索火山活动和弧火山滑坡的时间演化。对钻孔岩芯中的火山碎屑瀑布和火山碎屑浊积岩沉积物的分析揭示了蒙特塞拉特岛火山活动的三个加剧时期（930至900万年、810至760万年和190至120万年），这些时期与火山不稳定性增加和质量损失的时期相吻合。这些时期中最年轻的时期标志着苏弗里耶尔山火山活动的高峰。最大的侧翼崩溃，这座火山（约130万年）发生在这一时期结束时，两个年轻的滑坡也发生在一个时期的相对较高的火山活动。这三个滑坡代表了苏弗里耶尔山建筑群唯一的大型（>0.3 km 3）侧面崩塌，其发生时间也与海平面快速上升（>5 m/ka）的时期相吻合。其他岛弧火山的年龄数据表明，大规模滑坡的时间和海平面快速上升的时期之间存在普遍的相关性，但这并没有观察到板内海洋环境中的火山。因此，我们推断，海平面的快速上升可能会调节岛弧火山崩溃的时间，但在较大的海洋岛屿环境中则不然。
Hole U1395B, drilled southeast of Montserrat during Integrated Ocean Drilling Program Expedition 340, provides a long (>1 Ma) and detailed record of eruptive and mass‐wasting events (>130 discrete events). This record can be used to explore the temporal evolution in volcanic activity and landslides at an arc volcano. Analysis of tephra fall and volcaniclastic turbidite deposits in the drill cores reveals three heightened periods of volcanic activity on the island of Montserrat (∼930 to ∼900 ka, ∼810 to ∼760 ka, and ∼190 to ∼120 ka) that coincide with periods of increased volcano instability and mass‐wasting. The youngest of these periods marks the peak in activity at the Soufrière Hills volcano. The largest flank collapse of this volcano (∼130 ka) occurred toward the end of this period, and two younger landslides also occurred during a period of relatively elevated volcanism. These three landslides represent the only large (>0.3 km3) flank collapses of the Soufrière Hills edifice, and their timing also coincides with periods of rapid sea level rise (>5 m/ka). Available age data from other island arc volcanoes suggest a general correlation between the timing of large landslides and periods of rapid sea level rise, but this is not observed for volcanoes in intraplate ocean settings. We thus infer that rapid sea level rise may modulate the timing of collapse at island arc volcanoes, but not in larger ocean‐island settings.