from the book, "Petrified Lightning"
In 383 b.c., about two days before an earthquake destroyed the city, Helice, Greece, witnessed a mass evacuation of the city's rats, snakes, weasels, millipedes, and even worms. This animal movement was spectacular enough to be recorded by the Greek historian Diodorus, who quoted witnesses to the incident.
The Lisbon, Portugal, earthquake of 1755, which rang church bells in Sweden, is mentioned in the writings of German philosopher Immanuel Kant: "Eight days before the tremor the ground near Cadiz was covered with a multitude of worms that had crawled out of the ground."
On July 26, 1908, the night before a quake devastated Naples, Italy, great swarms of locusts crawled through the streets and into the sea. Oxen bellowed, sheep and goats bleated, dogs howled, and geese squawked noisily.
A rancher on Kodiak Island noted on March 27, 1964, that his cattle would not stay in their low—lying pasture. He didn't argue with whatever instinct took them to higher grazing land. When the earthquake came at 5:36 p.m. a great tsunami rolled over the lowlands. In that same great quake the Kodiak bears came out of hibernation two weeks early. Tracks showed that they didn't stop to feed as they normally would when awakening from their long winter sleep. Instead their tracks indicate that they left their rock caves and headed out on the run.
Few residents of Parkfield, California, will ever forget June 25, 1966, when the town was invaded by rattlesnakes. Why did the reptiles flee the dry, grassy hills nearby? The answer came two days later when the surrounding hills were shaken by a medium—to—heavy earthquake.
The night before the Sylmar earthquake of February 9, 1971, several police patrols reported independently to their dispatcher that enormous numbers of rats were scurrying through the streets of San Fernando, California. The police also received a number of complaints about incessant barking and howling of dogs for several hours before the 6:01 a.m. quake.
Although unusual animal behavior preceding earthquakes has been observed and reported throughout the world for hundreds of years, researchers have been reluctant to assign credibility to the phenomenon. Reports of animal anxiety, often mingled with allegory and legend, were considered flights of the imagination, superstition, fantasy, and old wives' tales. But now the collected accounts of many centuries are finally being accepted as reliable information.
In June 1974, China's National Earthquake Bureau issued a warning that a critical earthquake could be expected near the city of Haicheng, in Lianoning Province near Manchuria, within one to two years. This prediction was the result of a four—year study of a 2,200—year history of earthquakes in the area. Their conclusion that geologic changes were imminent was supported by precise seismologic, geodetic, and geomagnetic measurements.
The citizens were mobilized into a large—scale prediction network. With the guidance of experts, volunteers were placed in thousands of industrial plants, schools, animal breeding institutions, and agricultural communes; others were trained to observe animal behavior. They were alerted to recognize other signs of an impending earthquake, such as changes in the water table, bubbling in water wells, sulfur smells in wells, increased radon gas, earthquake swarms, weird lights, or strange rumbles coming from the ground. The collected information was assembled in a central clearinghouse.
Many observers acknowledged that the most widespread, predictable, and meaningful signs of an approaching earthquake were the strange behaviors of animals. They would signal their fears loudly, leave their burrows, and try to break out of any enclosure. Observers noted also that several small earthquakes definitely signaled a forthcoming earthquake. By February 1975, these signs had become very real.
More than 20 species of animals showed unmistakable signs of fear and confusion. Large animals such as horses and cows became unmanageable and panicked, kicking, biting, and running away. Snakes came out of hibernation, crawled from their burrows, and froze to death on the snow—covered ground. Rats appeared in the open in large groups, so confused that they could be caught by hand. Geese flew into walls and trees, pigs bit each other and dug out of their sties, chickens refused to enter their coops to roost. Even trained police dogs would not obey their handlers, but howled and kept their noses to the ground.
Several small earthquake swarms were detected in the first days of February. This evidence, along with groundwater changes such as wells turning cloudy and gas bubbles in ponds, convinced the scientists that the anomalies in animal behavior were relevant. On February 4, 1975, evacuation of the Haicheng area was ordered and was in progress by 2 p.m. The earthquake, 7.3 on the Richter scale, hit at 7:36 p.m. Over 50 percent of the houses were destroyed. In this city of about a half—million people, tens of thousands would have died but for this successful prediction and evacuation. The few casualties were stubborn individuals who insisted that this was all poppycock; their houses collapsed on top of them.
Eight months of observations by the Chinese produced the following telltale signs of imminent seismic activity: (1) a dramatic rise in incidents of abnormal animal behavior, (2) distinct changes in the groundwater level, and (3) swarms of small earthquakes. Buttressed by each other, these observable events are precursors to a significant main event.
Much progress is being made in the long—range study of earth movements. Technology for constructing earthquake—resistant buildings, bridges, and physical facilities is coming of age. But short—term predictions provide the most effective measure of earthquake preparedness; they signal when to evacuate. For this, the early warning signs provided by animals are a most important feature in earthquake prediction.