Earthquakes emerging to the surface are supposed to be a tell-tale sign that an earthquake (or a flood) might be on the way. At least, that's what some people think.
Dr. Ikeya at Osaka University has been studying earthworms and earthquakes. Ikeya’s laboratory experiments were conducted to see if exposure to an electrical field or electromagnetic pulses could elicit animal behavior similar to what has been reported prior to earthquakes. The results: fish showed panic reactions, and earthworms moved out of the soil and swarmed when current was applied.
When asked why he decided to study the relationship between earthworms and earthquakes, Ikeya said:
The Kobe earthquake in 1995. I live 30 km from the epicenter and thought it strange that many earthworms dug themselves up in my small garden. At the time, I did not know the legend that a number of emerging earthworms is a sign of a large earthquake. Many people noticed this, including my neighbors.
What about your pets or other critters? There are many theories that animals are more in tune with Mother Nature than humans. It's just something interesting to think about.
Here are some excerpts from an article on a U.S. Department of the Interior Website:
Rats, weasels, snakes, and centipedes reportedly left their homes and headed for safety several days befor a destructive earthquake. Anectdotal evidence abounds of animals, fish, birds, reptiles, and insects exhibiting strange behavior anywhere from weeks to seconds before an earthquake. However, consistent and reliable behavior prior to seismic events, and a mechanism explaining how it could work, still eludes us. Most, but not all, scientists pursuing this mystery are in China or Japan.
We can easily explain the cause of unusual animal behavior seconds before humans feel an earthquake. Very few humans notice the smaller P wave that travels the fastest from the earthquake source and arrives before the larger S wave. But many animals with more keen senses are able to feel the P wave seconds before the S wave arrives. As for sensing an impending earthquake days or weeks before it occurs, that's a different story.
A recent popular theory purports that there is a correlation between Lost Pet ads in the San Jose Mercury News and the dates of earthquakes in the San Francisco Bay area. A thorough statistical analysis of this theory, published in California Geology in 1988, concludes that there is no such correlation, however.
So what did you notice? Were your pets or critters acting strange before the quake?