Changes in continental water storage generate vertical surface deformation, induce crustal stress perturbations, and modulate seismicity rates. However, the degree to which regional changes in terrestrial water content influence crustal stresses and the occurrence of earthquakes remains an open problem. We show how changes in groundwater storage, computed for a ∼1,000 km² basin, focus deformation in a narrow zone, causing large horizontal, nonseasonal displacements. We present results from a karstic mountain range located at the edge of the Adria‐Eurasia plate boundary system in Northern Italy, where shortening is accommodated across an active fold‐and‐thrust belt. The presence of geological structures with high permeabilities and of deeply rooted hydrologically active fractures focus groundwater fluxes and pressure changes, generating transient surface horizontal displacements up to 5 mm and perturbations of crustal stress up to 25 kPa at seismogenic depths. The background seismicity rates appear correlated, without evident temporal delay, with groundwater storage changes in the hydrological basin. With no evidence of pore pressure propagation from the hydrologically active fractures, seismicity modulation is likely affected by direct stress changes on faults planes.

中文翻译：

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浅层地壳对地下水储量变化的机械响应：来自意大利南部南部阿尔卑斯山的变形和地震观测的推论

大陆储水量的变化会产生垂直表面变形，引起地壳应力扰动，并调节地震活动率。但是，地面含水量的区域变化在多大程度上影响地壳应力和地震的发生仍然是一个悬而未决的问题。我们展示了如何计算约1000 km ^2的地下水储量变化盆地，焦点在狭窄区域变形，引起较大的水平，非季节性位移。我们给出了来自意大利北部Adria-Eurasia板块边界系统边缘的一个岩溶山脉的结果，该区域在活动的褶皱-冲断带上具有缩短作用。具有高渗透性的地质结构和根深蒂固的水文活动裂缝的存在集中了地下水通量和压力变化，在地震发生深度产生了高达5 mm的瞬时表面水平位移和高达25 kPa的地壳应力扰动。在没有明显的时间延迟的情况下，背景地震活动率似乎与水文盆地的地下水储量变化相关。没有证据表明水文活动裂缝中的孔隙压力传播，