On the Nature of Reservoir-induced Seismicity
On the Nature of Reservoir-induced Seismicity
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DOI：
10.1007/s000240050089
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发表时间：
1997-12
影响因子：
2
通讯作者：
P. Talwani
中科院分区：
文献类型：
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作者：
P. Talwani
在大多数由水库引起的地震活动中，地震活动是在蓄水、湖泊水位大幅度变化或蓄水后发生的，而蓄水后的水位高于蓄水前达到的最高水位。我们把这归类为初始地震活动。这种“初始地震活动性”可归因于水库对初始充填或水位变化的耦合孔隙弹性响应。它的特点是在蓄水前水平以上地震活动性增加，大事件，总体稳定和（通常）水库最深部分以下缺乏地震活动性，外围广泛的地震活动性，向一个或多个方向向外迁移。随着时间的推移，地震的次数和震级都在减少，地震活动性恢复到蓄水前的水平。然而，几年后，一些储层继续活跃；然而，在其他地方没有地震活动。二维（类似Roeloffs， 1988）计算的初步结果表明，这种“延长期地震活动”取决于湖泊水位变化的频率和幅度、水库规模和基底的流体力学性质。强度变化显示出相对于湖面变化的延迟。较长周期的水位变化（~ 1年）比短周期的水位变化更有可能引起更深更大的地震。地震发生在湖泊水位变化相当大的水库，或者是最小水深的很大一部分。大型储层的地震活动性可能比小型储层更广泛、更深。在水库最深处和周围地区都观察到诱发地震活动。地震活动的位置是由储层下方和附近的断层性质决定的。
—In most cases of reservoir-induced seismicity, seismicity follows the impoundment, large lake-level changes, or filling at a later time above the highest water level achieved until then. We classify this as initial seismicity. This "initial seismicity" is ascribable to the coupled poroelastic response of the reservoir to initial filling or water level changes. It is characterized by an increase in seismicity above preimpoundment levels, large event(s), general stabilization and (usually) a lack of seismicity beneath the deepest part of the reservoir, widespread seismicity on the periphery, migrating outwards in one or more directions. With time, there is a decrease in both the number and magnitudes of earthquakes, with the seismicity returning to preimpoundment levels. However, after several years some reservoirs continue to be active; whereas, there is no seismicity at others. Preliminary results of two-dimensional (similar to those by Roeloffs, 1988) calculations suggest that, this "protracted seismicity" depends on the frequency and amplitude of lake-level changes, reservoir dimensions and hydromechanical properties of the substratum. Strength changes show delays with respect to lake-level changes. Longer period water level changes (∼1 year) are more likely to cause deeper and larger earthquakes than short period water level changes. Earthquakes occur at reservoirs where the lake-level changes are comparable or a large fraction of the least depth of water. The seismicity is likely to be more widespread and deeper for a larger reservoir than for a smaller one. The induced seismicity is observed both beneath the deepest part of the reservoir and in the surrounding areas. The location of the seismicity is governed by the nature of faulting below and near the reservoir.