Seismic constraints on caldera dynamics from the 2015 Axial Seamount eruption
Seismic constraints on caldera dynamics from the 2015 Axial Seamount eruption
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2015年轴向海山喷发对破火山口动力学的地震约束
DOI：
10.1126/science.aah5563
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发表时间：
2016-12
期刊：
影响因子：
56.9
通讯作者：
W. Wilcock;M. Tolstoy;F. Waldhauser;Charles Garcia;Yen Joe Tan;D. Bohnenstiehl;J. Caplan‐Auerbach;R. Dziak;A. Arnulf;M. E. Mann
中科院分区：
文献类型：
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作者：
W. Wilcock;M. Tolstoy;F. Waldhauser;Charles Garcia;Yen Joe Tan;D. Bohnenstiehl;J. Caplan‐Auerbach;R. Dziak;A. Arnulf;M. E. Mann
火山监测进入深轴海山是一座大型活跃的海底火山，位于美国西部海岸附近的胡安德富卡中洋脊。1998年和2011年的喷发之后是岩浆补给时期，这使它成为将其纳入海洋天文台倡议电缆阵列的理想地点。Wilcock等人。提供2015年4月最近一次喷发的实时地震数据，以便跟踪喷发前和喷发期间的岩浆。努纳和查德威克表明，根据变形数据，火山喷发是可以预测的。当岩浆在其下方汇聚时，轴向海山就会膨胀，当膨胀达到临界值时就会喷发。这两项研究都阐明了海底火山的动力学，海底火山的数量远远超过了地上火山的数量。《科学》，本期第1395页，第1399页，《地震数据》追踪了2015年4月轴向海山喷发期间岩浆的运动。在火山活动的火山口进行地震观测是具有挑战性的。在胡安德富卡海脊的轴海山顶上，一个新的有线天文台可以对海底火山口进行前所未有的实时监测。从2015年4月24日开始，地震网络捕捉到了一次喷发，最终以爆炸性的声音信号结束，熔岩在海底喷发。喷发前广泛的地震活动表明，向外倾斜的火山口环状断层的重新激活适应了通货膨胀，强烈的潮汐触发表明了一个临界应力系统。环形断层适应了喷发期间的泄气，并为在火山口东墙下向南和向北延伸的堤坝提供了一条通道。一旦在火山口以北，喷发就向西推进，一条堤坝沿着伸展的北部裂谷蔓延。
Volcano monitoring goes into the deep Axial Seamount is a large and active submarine volcano along the Juan de Fuca midocean ridge off the coast of the western United States. Eruptions in 1998 and 2011 were followed by periods of magma recharge, making it an ideal location to include in the Ocean Observatories Initiative Cabled Array. Wilcock et al. present real-time seismic data from the most recent eruption in April 2015 that allow the tracking of magma before and during eruption. Nooner and Chadwick show that eruptions are predictable on the basis of deformation data. As magma pools underneath it, Axial Seamount inflates and erupts when the inflation hits a threshold. Both studies elucidate the dynamics of submarine volcanoes, which vastly outnumber their aboveground counterparts. Science, this issue p. 1395, p. 1399 Seismic data track the movement of magma during the April 2015 Axial Seamount eruption. Seismic observations in volcanically active calderas are challenging. A new cabled observatory atop Axial Seamount on the Juan de Fuca ridge allows unprecedented real-time monitoring of a submarine caldera. Beginning on 24 April 2015, the seismic network captured an eruption that culminated in explosive acoustic signals where lava erupted on the seafloor. Extensive seismic activity preceding the eruption shows that inflation is accommodated by the reactivation of an outward-dipping caldera ring fault, with strong tidal triggering indicating a critically stressed system. The ring fault accommodated deflation during the eruption and provided a pathway for a dike that propagated south and north beneath the caldera’s east wall. Once north of the caldera, the eruption stepped westward, and a dike propagated along the extensional north rift.