NSFGEO-NERC: Investigating pre-, co-, and post-eruption processes at Sierra Negra volcano, Galapagos using geodetic and seismic data

塞拉内格拉火山位于厄瓜多尔Galápagos群岛，是地球上最大的玄武岩火山口之一，长9公里，宽7公里。通过NSF RAPID和NERC紧急项目的投资，2018年6月26日至8月30日塞拉内格拉火山的喷发是当地地球物理监测网络记录的Galápagos群岛火山的第一次喷发。得到的数据是惊人的。这次喷发包括喷发前6.5米的膨胀，在北坡形成了一个长达12公里的裂缝系统，8.5米的共喷发收缩（在火山口边界环断层上观测到的最大的共喷发位移之一），以及1.5米的净隆起（复苏）在火山口内活门断层系统上。数十万次地震伴随着喷发前和共喷发阶段，包括高达Mw5.4的火山口内“活板门”断层事件的通货膨胀和通货紧缩。NSFGEO-NERC合作计划非常适合将独特的、互补的大地测量和地震观测和建模结合起来，以解决与Sierra Negra的行为有关的具体问题，Galápagos火山活动的性质，以及关于基本火山变形和火山大厦与岩浆管道系统之间相互作用的重要悬而未决的问题。

Sierra Negra volcano, in the Galápagos Islands of Ecuador, is one of the largest basaltic calderas on Earth, measuring 9 km by 7 km. Through investments from the NSF RAPID and NERC Urgency programs, the June 26-August 30, 2018 eruption of Sierra Negra was the first eruption at a Galápagos Islands volcano to be recorded by a local geophysical monitoring network. The resulting data are spectacular. The eruption involved >6.5 m of pre-eruptive inflation, formation of a ~12 km long fissure system on the north flank, ~8.5 m of co-eruptive deflation (one of the largest co-eruptive displacements ever observed without collapse on caldera-bounding ring faults), and ~1.5 m of net uplift (resurgence) on the intra-caldera trapdoor fault system. Hundreds of thousands of earthquakes accompanied the pre- and co-eruptive phases, including inflationary and deflationary intra-caldera 'trapdoor' faulting events up to Mw5.4. The NSFGEO-NERC collaborative scheme is ideally suited to bring together unique, complementary geodetic and seismic observations and modeling to address specific questions relating to the behavior of Sierra Negra, the nature of Galápagos volcanism, and important outstanding questions about fundamental volcano deformation and interaction between a volcanic edifice and magma plumbing system.