Abstract. During the first two days of August 2016 a seismic crisis occurred on Brava, Cape Verde, which – according to observations based on a local seismic network – was characterized by more than thousand volcano-seismic signals. Brava is considered an active volcanic island, although it has not experienced any historic eruptions. Seismicity significantly exceeded the usual level during the crisis. We report on results based on data from a temporary seismic-array deployment on the neighbouring island of Fogo at a distance of about 35 km. The array was in operation from October 2015 to December 2016 and recorded a total of 1343 earthquakes, 355 thereof were localized. On 1 and 2 August we observed 54 earthquakes, 25 of which could be located beneath Brava. We further evaluate the observations with regards to possible precursors to the crisis and its continuation. Our analysis shows a migration of seismicity around Brava, but no distinct precursory pattern. However, the observations suggest that similar earthquake swarms commonly occur close to Brava. The results further confirm the advantages of seismic arrays as tools for the remote monitoring of regions with limited station coverage or access.

中文翻译：

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使用阵列方法远程监视佛群和佛得角布拉瓦2016年8月地震危机

摘要。在2016年8月的前两天，佛得角布拉瓦发生了地震危机，根据基于当地地震网络的观察，该危机的特征是上千个火山地震信号。布拉瓦被认为是活跃的火山岛，尽管它没有经历过任何历史性喷发。在危机期间，地震活动大大超过了正常水平。我们基于在邻近的Fogo岛上约35 km的距离上临时地震阵列部署的数据报告结果。该阵列于2015年10月至2016年12月运行，共记录了1343次地震，其中355次发生了局部地震。在8月1日至2日，我们观测到54次地震，其中25次可能位于Brava下方。我们进一步评估关于危机及其持续可能爆发的前兆的观察结果。我们的分析表明，布拉瓦附近发生了地震活动，但没有明显的前兆模式。但是，观察结果表明类似的地震群通常发生在布拉瓦附近。结果进一步证实了地震阵列作为用于远程监测站覆盖或访问受限的区域的工具的优势。