Picozzi Matteo, Iaccarino Antonio G, Spallarossa Daniele, Bindi Dino
University of Naples Federico II, Naples, Italy.
DISTAV, University of Genoa, Genoa, Italy.
Sci Rep. 2023 Sep 1;13(1):14403. doi: 10.1038/s41598-023-41625-0.
How, when and where large earthquakes are generated remain fundamental unsolved scientific questions. Intercepting when a fault system starts deviating from its steady behavior by monitoring the spatio-temporal evolution and dynamic source properties of micro-to-small earthquakes can have high potential as tool for identifying the preparatory phase of large earthquakes. We analyze the seismic activity that preceded the Mw 6.3 earthquake that hit L'Aquila on 6 April 2009 in central Italy, and we show that the seismic catalog information can be transformed into features allowing us to track in a statistical framework the spatio-temporal evolution of seismicity. Features associated to foreshocks show different patterns from the background seismicity that occurred in the previous years. We show that features ensemble allows to clearly capture the activation phase of the main event. Nonetheless, foreshocks share similar clustering properties of previous seismic sequences not culminating in large earthquakes, and thus generating questions on their use as potential precursor for earthquake sequences prone to evolve into catastrophic sequences.
大地震如何、何时以及在何处发生仍然是尚未解决的基本科学问题。通过监测微震到小震的时空演化和动态震源特性，来截获断层系统何时开始偏离其稳定行为，作为识别大地震准备阶段的工具具有很大潜力。我们分析了2009年4月6日发生在意大利中部拉奎拉的Mw 6.3级地震之前的地震活动，结果表明地震目录信息可以转化为特征，使我们能够在统计框架内追踪地震活动的时空演化。与前震相关的特征显示出与前几年背景地震活动不同的模式。我们表明，特征集合能够清晰地捕捉到主震的激活阶段。尽管如此，前震与之前未引发大地震的地震序列具有相似的聚类特性，因此引发了关于将其用作可能演变为灾难性序列的地震序列潜在前兆的疑问。
