Abstract We performed repeated three-dimensional seismic tomography in 2009–2018 for the area influenced by the intersection of the Silvia–Pijao (Buesaco) and Cauca–Almaguer fault systems beneath Galeras volcano, Colombia. We analyzed two periods, 2009–2012 and 2013–2018, which were characterized by explosive eruptive activity and relative quiescence at Galeras, respectively. We used P- and S-wave arrival times of 2848 (2009–2012) and 2289 (2013–2018) earthquakes that occurred beneath the volcano. P- and S-wave velocity (Vp and Vs, respectively) anomalies and their changes between the two periods were interpreted to be associated with magma movement in the volcanic plumbing system, which was controlled by the intersection of the faults. Two possible pathways of magma ascent and accumulation were identified in the fault systems. One, located SW of the active crater, consisted of areas with high Vp/Vs values (>1.9) at depths of −2 to 4 km below sea level, and the other located NE of the active crater with high and low Vp/Vs values. The low-Vp/Vs (

中文翻译：

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2009-2018 年重复地震层析成像揭示哥伦比亚 Galeras 火山岩浆管道系统的时间变化

摘要 我们在 2009-2018 年对哥伦比亚 Galeras 火山下的 Silvia-Pijao (Buesaco) 和 Cauca-Almaguer 断层系统的交叉影响区域进行了重复的三维地震断层扫描。我们分析了 2009-2012 年和 2013-2018 年两个时期，其特征分别是 Galeras 的爆发性喷发活动和相对静止。我们使用了发生在火山下方的 2848（2009-2012）和 2289（2013-2018）地震的 P 波和 S 波到达时间。P 波和 S 波速度（分别为 Vp 和 Vs）异常及其在两个时期之间的变化被解释为与火山管道系统中的岩浆运动有关，该系统由断层的交叉点控制。在断层系统中确定了两种可能的岩浆上升和聚集途径。一，位于活动火山口 SW 的区域由海平面以下 -2 至 4 公里深度具有高 Vp/Vs 值（>1.9）的区域组成，另一个位于活动火山口的 NE 具有高和低 Vp/Vs 值。低 Vp/Vs (