The appearance of unusual deep-sea fishes, like oarfish, doesn't predict a forthcoming earthquake, new statistical analysis suggests. Photo by Biodiversity Heritage Library/Flickr
June 19 (UPI) -- The appearance of deep-sea fish in shallow waters along the coast of Japan doesn't predict the arrival of an earthquake, according to a new study.
Seismologists compared the frequency and timing of reported appearances of oarfish and slender ribbonfish with earthquake records in Japan. In total, scientists studied the timing and location of 336 fish sightings and 221 earthquakes.
The results -- published this week in the Bulletin of the Seismological Society of America -- showed only one plausible correlation between the phenomena.
Previous reports of unusual animal behavior suggested a link between deep-sea fish appearances and large earthquakes. But researchers found no records of deep-sea fish in the 10 days preceding a magnitude 7 earthquake. Scientists also confirmed no magnitude 6 earthquakes arrived within 10 days of deep-sea fish sightings.
After the 2011 magnitude 9.0 Tohoku earthquake, Yoshiaki Orihara of Tokai University in Japan began considering the possibility that the stories of deep-sea fish appearances were true. If they were, the behavior of oarfish and ribbonfish could aid Japan's earthquake warning system.
"From this motivation, we started compiling the event catalog for statistical study," Orihara said in a news release. "There were some previous papers to survey deep-sea fish appearances. However, their reports were insufficient for a statistical study. To collect a lot of events, we focused on local newspapers that have often reported the events."
Orihara and his colleagues surveyed a digital newspaper database for stories about the appearance of deep-sea fish, including oarfish, ribbonfish, dealfish and the unicorn crestfish.
Researchers hope their work will discredit the myth of deep-sea creatures' earthquake-predicting powers.
More reliable earthquake-predicting technologies and methods are forthcoming. Scientists have identified early seismic signals that could help predict especially big earthquakes, while gravitational data has shown promise as a predictor of major fault slips.