Caldera resurgence during the 2018 eruption of Sierra Negra volcano, Galápagos Islands.
Caldera resurgence during the 2018 eruption of Sierra Negra volcano, Galápagos Islands.
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DOI：
10.1038/s41467-021-21596-4
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发表时间：
2021-03-02
影响因子：
16.6
通讯作者：
Stock MJ
中科院分区：
文献类型：
--
作者：
Bell AF;La Femina PC;Ruiz M;Amelung F;Bagnardi M;Bean CJ;Bernard B;Ebinger C;Gleeson M;Grannell J;Hernandez S;Higgins M;Liorzou C;Lundgren P;Meier NJ;Möllhoff M;Oliva SJ;Ruiz AG;Stock MJ
最近的大型玄武岩喷发是在轻微的地表隆起和地震活动之后开始的，并导致火山口下沉。相反，Galápagos岛火山的一些喷发之前是长时间的、大幅度的隆起和地震活动的增加。这些系统也显示出长期的火山口内隆起或复苏。然而，由于缺乏观察，这种行为背后的机制变得模糊不清。在这里，我们结合了一个独特的多参数数据集，以显示2018年塞拉内格拉火山喷发是如何导致火山口复活的。在13年的时间里，一个浅层水库的岩浆供应推动了6.5米的喷发前隆起和地震活动，其中包括引发喷发的5.4级地震。虽然岩浆共喷发导致8.5米的沉降，但活门断层上的内火山口的净隆起导致1.5米的永久回潮。这些观测结果揭示了破火山口内断裂对火山喷发的重要影响，以及在没有发育良好的裂谷系统的情况下火山喷发的机制。作者在此介绍了加拉帕戈斯岛塞拉内格拉火山完整喷发周期（2005-2018）的大地测量和地震数据。这些数据显示了在玄武岩喷发之前观测到的最大的喷发前膨胀（6.5米）和地震活动率，并提供了破火山口复活机制的罕见插图。
Recent large basaltic eruptions began after only minor surface uplift and seismicity, and resulted in caldera subsidence. In contrast, some eruptions at Galápagos Island volcanoes are preceded by prolonged, large amplitude uplift and elevated seismicity. These systems also display long-term intra-caldera uplift, or resurgence. However, a scarcity of observations has obscured the mechanisms underpinning such behaviour. Here we combine a unique multiparametric dataset to show how the 2018 eruption of Sierra Negra contributed to caldera resurgence. Magma supply to a shallow reservoir drove 6.5 m of pre-eruptive uplift and seismicity over thirteen years, including an Mw5.4 earthquake that triggered the eruption. Although co-eruptive magma withdrawal resulted in 8.5 m of subsidence, net uplift of the inner-caldera on a trapdoor fault resulted in 1.5 m of permanent resurgence. These observations reveal the importance of intra-caldera faulting in affecting resurgence, and the mechanisms of eruption in the absence of well-developed rift systems. The authors here present geodetic and seismic data for a complete eruptive cycle (2005-2018) for Sierra Negra volcano, Galapagos Island. The data shows the largest pre-eruptive inflation (6.5 m) and rates of seismicity ever observed before a basaltic eruption and provides a rare illustration of caldera resurgence mechanisms.
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影响因子：
3
作者：
Hardebeck, JL;Shearer, PM
通讯作者：
Shearer, PM
影响因子：
3.5
作者：
Chadwick, William W., Jr.;Jonsson, Sigurjon;Ruiz, Andres
通讯作者：
Ruiz, Andres
影响因子：
5.8
作者：
Chadwick, William W., Jr.;Geist, Dennis J.;Meertens, Charles M.
通讯作者：
Meertens, Charles M.
影响因子：
3.5
作者：
Geist, Dennis J.;Harpp, Karen S.;Rader, Erika
通讯作者：
Rader, Erika
影响因子：
5.3
作者：
Bagnardi, Marco;Amelung, Falk;Poland, Michael P.
通讯作者：
Poland, Michael P.