The seismic crisis unfolding in the Azores: earthquakes accompanying a rarely observed submarine eruption?

亚速尔群岛（Faial）一座火山岛以西的海底发生了一系列地震，这为我们提供了一个令人兴奋的机会，可以发现海底火山锥是如何形成的，这反过来又有助于我们了解海底火山爆发的风险。游泳位于一个细长的火山（秃鹰海山）的一端，那里有小的火山锥和山脊。我们将在基地周围的海床上安装4个地震仪，以便在两个月内记录更多的地震。通过精确定位这些地震，我们将能够确定断层和充满熔岩的裂缝（岩脉）的几何形状。如果发生了火山喷发，海底将会改变形状——这将根据2020年夏天新声纳调查收集的多波束回声测深仪数据得出。综合结果将告诉我们是否有过喷发，如果有的话，喷发与地球深处的熔岩供应有什么关系。此外，我们将能够重新评估穿过邻近海底火山的地震波，看看这些地震波是否具有岩浆房预期的异常低的速度。来自地震仪的新结果将用于更新亚速尔群岛政府科学家使用的软件，以确定地震发生的位置和震级，从而为当地居民提供监测服务。这将进一步帮助我们弄清楚地震群的性质（是否与地下熔岩运动或断层运动有关）。与太平洋相比，大西洋海底火山爆发的频率较低，但对船只、海底电缆和当地居民构成了威胁，相关的地震和山体滑坡会引发海啸。了解亚速尔群岛的这一事件将有助于描述这一更广泛的威胁，鉴于英国拥有大片海域，包括火山活跃的阿森松岛和特里斯坦达库尼亚群岛周围的海域，这对英国来说非常重要。

A swarm of earthquakes on the seabed west of a volcanic island in the Azores (Faial) presents an exciting opportunity to find out potentially how submarine volcanic cones form and this in turn helps us to understand the risks from submarine eruptions. The swam lies at one end of an elongated volcano (Condor Seamount) where there are small volcanic cones and ridges. We will install 4 seismometers on the seabed around the site to record further earthquakes over two months. By accurately locating those earthquakes, we will be able to determine the geometries of faults and cracks filled with lava (dykes). If there has been an eruption, the seabed will have changed shape - this will be worked out from multibeam echo-sounder data collected in a new sonar survey in the summer of 2020. The combined results will show us whether there has been an eruption and if so how that eruption related to the molten lava supplied deeper in the Earth. In addition, we will be able to reassess seismic waves that have travelled through the adjacent submarine volcano to see if those waves have unusually low velocities expected for a magma chamber. The new results from the seismometers will be used to update software used by government scientists in the Azores to work out where earthquakes occur and their magnitudes, hence their monitoring service for the local population. This will further help us work out the nature of the earthquake swarm (whether associated with subterranean movement of lava or movements on faults). Submarine volcanic eruptions are less frequent in the Atlantic compared with the Pacific Ocean, but are a risk to ships, seabed cables and to local populations where associated earthquakes and landslides cause tsunamis. Understanding this Azorean event will help characterize this broader threat, of importance to the UK given its large sea areas, including those around volcanically active Ascension and Tristan da Cunha islands.