Abstract Edifice collapse represents one of the most dangerous volcanic hazards threatening communities and infrastructure near volcanoes, having caused over 20,000 casualties in the past 400 years. Despite its prevalence across volcanic settings, flank instability has mostly been considered at ocean island volcanoes. In Guatemala, all but one volcano with elevation greater than 2000 m have undergone edifice failure. Pacaya is one of these Guatemalan volcanoes, which experienced at least one past episode of flank collapse and where recent transient flank motion has been identified. Using Interferometric Synthetic Aperture Radar (InSAR) time-series analysis, we reveal, for the first time, long-term displacement of the southwest flank of Pacaya between 2010 and 2014, including the interval 2011–2013 where the volcano remained relatively quiescent. Subsequent geodetic data inversions and static stress change analysis suggest that the observed flank motion could be accommodated by slip on a southwest-dipping detachment fault, with an observed increase in slip rate attributed to magma intrusion associated with a major eruption in 2014. This study highlights that long-term volcanic flank creep is likely more widespread than previously recognized and that magma-faulting interactions, as well as the existence of structural weaknesses within volcanic edifices, are vital considerations in the assessment of likelihood and nature of flank collapse at volcanoes worldwide.

中文翻译：

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使用卫星大地测量法解开危地马拉帕卡亚火山的长期火山侧翼不稳定性

摘要 建筑物倒塌是威胁火山附近社区和基础设施的最危险的火山灾害之一，在过去 400 年中已造成 20,000 多人伤亡。尽管它在火山环境中普遍存在，但在海洋岛屿火山中主要考虑侧翼不稳定性。在危地马拉，除了一座海拔超过 2000 米的火山外，其他所有火山都发生了建筑物倒塌。帕卡亚火山是这些危地马拉火山之一，该火山过去至少经历了一次侧翼坍塌，并且已经确定了最近的瞬态侧翼运动。使用干涉合成孔径雷达 (InSAR) 时间序列分析，我们首次揭示了 2010 年至 2014 年间帕卡亚西南翼的长期位移，包括火山保持相对静止的 2011 年至 2013 年区间。