这两天媒体报导英国有研究人员“发现”蟾蜍能够预报地震，论文发表在Journal of Zoology上面。中文媒体也有翻译报导。Discovery.com的一位博客作者就此请教了Susan Hough（她是美国地质调查局和加州理工学院工作人员，经常在地震之后出面向公众介绍地震知识），Susan Hough做了回答。
In order to take a serious look at whether this toad thing has anything to it — and whether the little buggers were somehow able to read electrical signals from the edge of space — I consulted with Susan Hough, a seismologist at Caltech. After having a read of the paper, here’s what she had to say:
This is a good example of bad science. The earthquake prediction heyday of the 1970s was launched and sustained by similar studies: people who found snippets of data after the fact that showed an apparent correlation between some signal and an eventual earthquake. This is not good statistics. You can’t select data after the fact.
In this case, there’s no way to know what kind of fluctuations are normally seen in toad activity, or what else might have been going on in the study area that could have influenced toad behavior.
It is within the realm of possibility that there are precursory signals before some earthquakes, and that animals might respond to them. But to demonstrate a significant correlation one would need to have a long record of objectively-recorded data before and after many earthquakes.
On the question of the ionosphere, she added:
There have been a number of studies of satellite observations that approach the bar for good science, in terms of applying rigorous statistics, etc. And, again, it is within the realm of possibility that VLF [Very Low Frequency] precursors exist.
But the snippets of data shown are insufficient to draw conclusions.
There are really two questions: 1) do precursors exist, and 2) do useful precursors exist? It is possible that precursory signals — electromagnetic, whatever — are generated in the earth prior to SOME earthquakes, but these precursors, if they exist, will have no predictive capability if they do not reliably occur before large earthquakes, and only before large earthquakes.