Transient crustal deformation from karst aquifers hydrology in the Apennines (Italy)
Transient crustal deformation from karst aquifers hydrology in the Apennines (Italy)
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DOI：
10.1016/j.epsl.2018.10.019
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发表时间：
2019-01
影响因子：
5.3
通讯作者：
F. Silverii;N. D’Agostino;A. Borsa;S. Calcaterra;P. Gambino;R. Giuliani;M. Mattone
中科院分区：
文献类型：
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作者：
F. Silverii;N. D’Agostino;A. Borsa;S. Calcaterra;P. Gambino;R. Giuliani;M. Mattone
空间大地测量技术的精确度和时空分辨率不断提高，对研究水团重新分布引起的地壳浅层变形产生了积极影响。在雪和水的变化很大并持续足够长时间的地区，已经记录了可测量的变形。在这里，我们分析GPS时间序列和水文数据从亚平宁山脉，一个构造活跃的地区托管大型岩溶含水层。我们记录了区域尺度的水平和垂直瞬时变形的发生，这显然与季节性和多年的水文变化。这些瞬态信号，这是最强烈的GPS网站周围的主要岩溶含水层，调制长期的构造变形。我们的研究结果表明，在这一地区的岩溶含水层的经验交替期的膨胀和收缩，以响应增加/减少降水，因此，较高/较低的水头在含水层。由于密集的连续GPS网络和互补的水文数据集的可用性，我们能够验证导致观测到的变形的过程。我们在该地区的浅地壳模型作为一个连续的滞弹性固体和有限应变长方体源使用绿色的功能来估计与GPS观测的应变率分布。我们使用Mw6.1拉奎拉地震，在2009年袭击了亚平宁山脉中部，其影响是显而易见的大地测量数据，记录的潜在影响，中度地震对岩溶含水层，并证明正确辨别构造非构造信号的大地测量时间序列的重要性。加强了解岩溶含水层的行为是主要的利益，以改善这一重要的水资源的管理，并为更好地了解地下水含量和孔隙压力变化之间可能的相互作用，在地壳和地震活动。
The increasing accuracy and spatiotemporal resolution of space geodetic techniques have positively impacted the study of shallow crustal deformation in response to the redistribution of water masses. Measurable deformations have been documented in areas where snow and water variability is large and persists over sufficiently long periods. Here we analyze GPS time series and hydrological data from the Central-Southern Apennines, a tectonically-active region hosting large karst aquifers. We document the occurrence of regional-scale horizontal and vertical transient deformation that is clearly correlated to seasonal and multiyear hydrological variability. These transient signals, which are most strongly observed at GPS sites surrounding the main karst aquifers, modulate long term tectonic deformation. Our results suggest that the karst aquifers in this region experience alternating periods of expansion and contraction in response to increasing/decreasing precipitation and, consequently, higher/lower hydraulic head in the aquifers. Thanks to the availability of a dense continuous GPS network and complementary hydrological datasets, we are able to verify the processes causing the observed deformation. We model the shallow crust in the region as a continuous anelastic solid and use Green's functions for finite strain cuboid sources to estimate the strain rate distribution associated with the GPS observations. We use the Mw6.1 L'Aquila earthquake, which struck the Central Apennines in 2009 and whose effects are evident in geodetic data, to document the potential effects of moderate earthquakes on karst aquifers and to demonstrate the importance of correctly discerning tectonic from nontectonic signals in geodetic time series. Enhanced understanding of the karst aquifers behavior is of primary interest for improved management of this vital water resource and for a better understanding of the possible interactions between groundwater content and pore pressure variations in the crust and seismicity.