In January 1975, hundreds of snakes unexpectedly appeared from their hibernation tunnels near Haicheng, a city northeast of Beijing, startling Chinese fieldworkers and woodcutters before freezing to death in the snow.
Farmers in the area observed abnormal behavior from livestock at the same time. Horses and cows continually tried to escape their corrals and refused to enter barns. Hens stopped producing eggs for a week while chickens roamed around in a panic. Cats bristled and refused to stay inside while dogs howled day and night.
Many fish were spotted leaping from rivers and lakes, while tigers, deer, and birds were said to have been seen leaving the region.
The water level in backyard wells was also reported to have changed significantly by the locals. Within a few days, scientists started to map telltale changes in the Earth's magnetic field and ground tilt.
Emergency personnel evacuated the inhabitants of Haicheng on February 3. A few hours later, 90% of the city's structures were destroyed or severely damaged by an earthquake with a magnitude of 7.3. There were few reported human casualties; thousands of lives had been saved by the prompt warnings.
The scientific process, which has long sought a technique to forecast earthquakes, was excited by the Haicheng event.
The connection between unusual animal behavior and earthquakes has attracted a lot of attention. To prove scientifically what has been maintained in mythology and legend for hundreds of years—those animals can feel approaching temblors—the U.S. Geological Survey initiated three investigations.
Observing captured mice and kangaroo rats in an earthquake-prone area, gathering 1,700 volunteers in seismically active areas to report unusual animal behavior via a telephone hotline, and speaking with locals near five earthquake epicenters were all parts of the three studies carried out in California in the late 1970s. While some odd animal behavior was seen, none of the three experiments could be conclusively concluded.
Don Dupras, an associate geologist for the California Department of Mines and Geology, remarked that an experiment must be repeatable for it to be taken seriously in science. The issue is how to set up a repeatable, controlled experiment given how unpredictable earthquakes are. ”
Researchers from UCLA established a mock outdoor habitat for around 50 pocket mice in the Morongo Valley, some 30 miles north of Palm Springs, as one of many attempts to study animal behavior. Because pocket mice don't drink water, they were chosen because they were simple to separate. Robert Lindberg, a research biologist at UCLA, explained, "We had one cage above ground and a connected cage buried under the ground." It was the closest thing we could get to a natural setting.
In addition, several kangaroo rats kept in indoor cages were observed.
The three greatest quakes, which occurred on March 15, 1979, had magnitudes of 5.2, 4.9, and 4.8. Moreover, more than 35 minor quakes were noted. During the stronger quakes, the ground reportedly shifted for up to 20 seconds, according to researchers.
The UCLA researchers wrote, "To our evident delight, considerable, and in some cases dramatic, activity anomalies were documented from the majority of animals in both the indoor and outdoor activities. However, the investigation concluded that the increased activity might have been caused by human interference during feeding time or by a rise in the temperature of the outside air during the spring.
According to Lindberg, "the overall impression I get is that we didn't have strong evidence of animals acting differently." "We did have a few pocket mice run above ground right before the quake swarm on March 15 at a time when they are typically in their underground cages. But, that might have been caused by the warmer weather we were having. Sadly, we were unable to establish whether animals could or could not foresee earthquakes.
SRI International from Menlo Park conducted the second Geological Survey research (formerly the Stanford Research Institute). A total of 1,700 volunteers were enlisted in Humboldt County, the San Francisco Bay Area, and Los Angeles County to report unusual animal behavior via a toll-free hotline. The messages were recorded and logged by researchers.
The calls that came in right after an earthquake was detected were rejected, according to Leon Otis, the project's chief investigator. We believed that previous to the earthquake, reports of strange animal behavior would be more accurate.
13 earthquakes with a Richter scale magnitude greater than 4.0 were registered in the study area over a four-year period. Researchers saw a "significant" spike in calls during seven of the 13 earthquakes. (Reports of fish jumping, dogs howling, ants swarming, general unrest among livestock, and domestic birds biting and killing their young were among some of the incidents.)
Only one instance, though, had dramatic repercussions. In a 30-day period following the magnitude 4.3 Fremont earthquake in 1981, 21 calls to the hotline were made, with an average of one call per day.
"We thought there could be something there, and I still think so. Yet, in the absence of proof, we can only regard the Fremont episode as speculative," Otis stated.
University of California, Davis hosted the third Geological Survey research. Five earthquakes were studied, and within days after the quakes, residents within less than three miles of the epicenters were questioned about any strange animal behavior they may have seen.
The findings in four of the five incidents were comparable to those at Ovando, Montana, where only one out of 35 people noticed any unusual behavior before an earthquake that measured 4.9. One instance can be found in Willits, Northern California, where 17 out of 50 people interviewed reported seeing strange animal behavior within a week of a 4.7 earthquake.
The three studies had some intriguing findings, despite the fact that their results were inconclusive, according to Otis. "Unfortunately, under the present Government, federal funding for animal and seismic tests has ceased. There are no more planned studies as far as I know.
Several animals have seismic sensory abilities that are significantly superior to those of humans, according to research done in the lab.
For instance, fish have incredibly sensitive otolithic organs in their ears, which are capable of detecting seismic activity that is up to three magnitudes weaker than that observed by humans. This includes the minuscule foreshocks that commonly precede significant earthquakes but are too small to register on the Richter scale.
The ability to detect extremely modest gradients of water displacement that can be brought on by the foreshocks of underwater earthquakes is shared by a variety of fish and amphibians. The ability to detect light electromagnetic fluctuations caused by early earthquake activity may also be shared by catfish, sharks, and rays. Animals that live on the ground may also experience foreshocks before people do.
Additionally, some scientists postulate that a variety of animals may include microscopic magnetite crystals in their brains that are vulnerable to seismic changes in the Earth's magnetic fields, which are the predecessors to the majority of earthquakes.
Yet for the most part, scientists have given up on using animals as earthquake predictors. There are no longer any active studies involving animals and earthquakes. Almost everyone has given up on the idea of animals, including China, according to Dupras of the California Department of Mines and Geology.
Following the shaker on October 1, a haphazard examination of the Los Angeles Zoo produced similarly conflicting data.
The day before the earthquake, none of our keepers saw any strange behavior, according to Laura LaMarca, the zoo's curator of education. "Our gorillas refused to return to their holding cage after the main shock and before the aftershocks. Yet, in my opinion, that was just common sense and not predictive behavior.