5.3 year time series of formation pore fluid pressure and temperature from IODP Hole 319-C0010A measured by GeniusPlug from 2010 to 2016

One primary objective of Integrated Ocean Drilling Program Expedition 365, conducted as part of the Nankai Trough Seismogenic Zone Experiment, was to recover a temporary observatory emplaced to monitor formation pore fluid pressure and temperature within a splay fault in the Nankai subduction zone offshore SW Honshu, Japan. Here we use a 5.3 year time series of formation pore fluid pressure, and in particular the response to ocean tidal loading, to evaluate changes in pore pressure and formation and fluid elastic properties induced by earthquakes. Our analysis reveals 31 earthquake‐induced perturbations. These are dominantly characterized by small transient increases in pressure (28 events) and decreases in ocean tidal loading efficiency (14 events) that reflect changes to formation or fluid compressibility. The observed perturbations follow a magnitude‐distance threshold similar to that reported for earthquake‐driven hydrological effects in other settings. […]

综合海洋钻探计划（Integrated Ocean Drilling Program）第365次探险活动，作为南海槽地震带实验的一部分，其主要目标之一是从日本西南部本州海外的南海槽俯冲带中提取一个临时观测站，用以监测构造孔隙流体压力和温度。在本研究中，我们利用了5.3年的构造孔隙流体压力时间序列数据，特别是对海洋潮汐负荷响应的数据，以评估地震引起的孔隙压力及构造和流体弹性性质的变化。我们的分析揭示了31次地震诱导的扰动。这些扰动主要表现为压力的短暂小幅上升（28次事件）和海洋潮汐负荷效率的降低（14次事件），反映了构造或流体压缩性的变化。观察到的扰动遵循与在其他环境下报道的地震驱动水文效应相似的震级-距离阈值。