Abstract Earthquakes can occasionally trigger the eruption or increase the activity of mud volcanoes and other fluid seepage systems. One long pending question is how static and dynamic stress changes can trigger eruptions of fluid expulsion features and modulate their activity. This study addresses the potential role of static and dynamic stress changes by investigating some well documented examples of triggered historical and recent eruptions in the Northern Apennines (Italy) and partly Azerbaijan. Peak dynamic stress at triggered fluid expulsion features has been estimated using measured PGV, or PGV estimated from attenuation relationships. The results suggest that seepage features are often triggered by dynamic stress changes created by earthquake faults located in the intermediate- to far-field. Paroxysmal activity of the considered fluid expulsion systems was influenced by minimum dynamic stress thresholds ranging from approximately 30–50 kPa to 15 kPa. Regarding co-seismic static stress changes, their magnitude can be large enough to dilate fault-controlled fluid pathways located in the near-field of a ruptured fault. This may be the case of the Pede-Apennine thrust (in northern Italy), which ruptured in 1501 (Mw ~6) beneath many mud volcanoes. Apart from this case, the considered fluid expulsion systems that responded to the earthquakes were stressed by negligible or subordinate changes in static stress, with few exceptions. Earthquake-related stresses have the ability to influence the eruptive activity of fluid seepage systems, but the recovery time between two consecutive eruptions is usually irregular. This variability in the repose time suggests that the achievement of a critical or trigger-able state is governed by a complex interplay among independent factors (e.g., production rate of driving gases, plumbing system characteristics, frequency of triggering earthquakes).

中文翻译：

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通过动态和静态应力研究流体渗漏系统的地震触发

摘要 地震偶尔会引发火山喷发或增加泥火山和其他流体渗流系统的活动。一个长期悬而未决的问题是静态和动态压力变化如何触发液体排出特征的爆发并调节其活动。本研究通过调查北亚平宁山脉（意大利）和部分阿塞拜疆地区历史和近期爆发的一些有据可查的例子，探讨了静态和动态压力变化的潜在作用。已使用测量的 PGV 或根据衰减关系估计的 PGV 估计触发流体排出特征处的峰值动态应力。结果表明，渗流特征通常是由位于中场到远场的地震断层产生的动态应力变化触发的。所考虑的流体排出系统的阵发性活动受到范围从大约 30-50 kPa 到 15 kPa 的最小动态应力阈值的影响。关于同震静应力变化，它们的大小可以大到足以扩张位于破裂断层近场的断层控制的流体通道。这可能是 Pede-Apennine 逆冲断层（在意大利北部）的情况，它在 1501 年（Mw ~6）在许多泥火山下破裂。除了这种情况外，所考虑的对地震做出反应的流体排出系统受到静应力的可忽略或次要变化的压力，很少有例外。地震相关的压力有能力影响流体渗流系统的喷发活动，但两次连续喷发之间的恢复时间通常是不规则的。