Swiss Seismological Service, ETH Zurich, Zurich, Switzerland.
Nature. 2019 Oct;574(7777):193-199. doi: 10.1038/s41586-019-1606-4. Epub 2019 Oct 9.
Immediately after a large earthquake, the main question asked by the public and decision-makers is whether it was the mainshock or a foreshock to an even stronger event yet to come. So far, scientists can only offer empirical evidence from statistical compilations of past sequences, arguing that normally the aftershock sequence will decay gradually whereas the occurrence of a forthcoming larger event has a probability of a few per cent. Here we analyse the average size distribution of aftershocks of the recent Amatrice-Norcia and Kumamoto earthquake sequences, and we suggest that in many cases it may be possible to discriminate whether an ongoing sequence represents a decaying aftershock sequence or foreshocks to an upcoming large event. We propose a simple traffic light classification to assess in real time the level of concern about a subsequent larger event and test it against 58 sequences, achieving a classification accuracy of 95 per cent.
大地震发生后，公众和决策者最关心的问题是，这是即将到来的更强烈事件的主震还是前震。到目前为止，科学家只能提供过去序列统计汇编的经验证据，他们认为正常情况下余震序列会逐渐衰减，而即将发生的更大事件的概率为百分之几。在这里，我们分析了最近阿马特里切-诺尔恰和熊本地震序列的余震平均大小分布，我们认为在许多情况下，可能有可能区分正在发生的序列是代表衰减的余震序列还是即将发生的大型事件的前震。我们提出了一种简单的红绿灯分类法，以便实时评估对后续更大事件的关注程度，并将其与 58 个序列进行了测试，准确率达到了 95%。
