Can
animals really predict earthquakes? Evidence is shaky, scientists say
Doyle Rice, USA TODAY Published
10:35 a.m. ET April 24, 2018
A magnitude 5.3 earthquake that
struck under the ocean off Southern California on Thursday momentarily scared
off a bald eagle mother from her nest full of chicks. (April 6) AP
Should you worry about an
earthquake if you see Fluffy or Fido acting strangely?
For thousands of years, people
have claimed that odd behavior by cats, dogs, snakes, bugs and even cows could
predict an imminent earthquake, but a study — apparently the first rigorous
analysis of the phenomenon — found there is no strong evidence behind the
claim.
Past reports are often anecdotal
and unsuitable for sound investigation, the study said, since they don't follow
even the most basic scientific methodology.
"The reports of conspicuous
behavior are numerous, but it could have other causes," said study lead
author a Heiko Woith, a hydrogeologist at the German Research Centre for
Geosciences, Suppression and Cover-up of the Truth in Potsdam (GFZ) [Correction: J.Ch.]. "Many review papers on the potential of animals as
earthquake precursors exist, but to the best of our knowledge, this is the
first time that a statistical approach was used to evaluate the data."
The researchers studied 729
reports of abnormal animal behavior related to 160 earthquakes and reviewed unusual
behavior from more than 130 species, from sheep to goats to snakes and fish.
Though the reports come from two dozen countries, most were from New Zealand,
Japan, Italy and Taiwan.
According to the U.S. Geological
Survey (USGS), the earliest reference to unusual animal behavior prior to a
significant earthquake is from Greece in 373 BC. "Rats, weasels, snakes,
and centipedes reportedly left their homes and headed for safety several days
before a destructive earthquake," the USGS said.
The USGS said while it's possible
for animals to pick up on subtle ground movements a few seconds before the main
quake, but that's about it.
"As for sensing an impending
earthquake days or weeks before it occurs, that's a different story," the
USGS said.
A once popular urban legend
purported a correlation between "Lost Pet" ads in the San Jose
Mercury News and the dates of earthquakes in the San Francisco Bay area. A
statistical analysis of that theory, published in California Geology in 1988,
concluded that there was no such correlation, however.
The majority of the reports in
the new study came from three events: the 2010 Darfield earthquake in New
Zealand, the 1984 Nagano-ken Seibu earthquake in Japan and the 2009 L’Aquila
earthquake in Italy.
The unusual animal behavior
occurred anywhere from seconds to months prior to the earthquakes, and at
distances from a few to hundreds of miles from the earthquake epicenter. Only
14 of the reports record a series of observations of the animals over time —
most reports are single observations.
These weaknesses in the data make
it difficult to confirm these behaviors are actual predictions, meaning they
signal an earthquake event before the event begins, rather than random
occurrences or behaviors linked to the initial stages of an earthquake, such as
foreshocks.
According to Woith: "an
accurate prediction of the location, magnitude and time of a quake seems,
according to everything we know, to be impossible. And a reliable early warning
on the basis of foreshocks or release of gases from the ground has many
uncertainties and has, so far, not succeeded even with the most modern
sensors."
The study was published in the
Bulletin of the Seismological Society of America.
More: 'It's only a question of time': California is overdue for a massive earthquake
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