Major Earthquakes in Japan this Century
The Big One (The Great California Earthquake)
(Introduction from a book by: George Pararas-Carayannis)
Contents (To be added) Earthquakes: What Are They? Experiencing An
Earthquake; The California Fault System; Historical California Earthquakes; Earthquake Prediction; Methods Used In Earthquake Prediction; The Big One: When and Where will the Big Earthquake Strike California? Determining Earthquake Risk; Reducing The California Earthquake Hazard
Earthquake Awareness And Preparedness. Protection Of Property from Earthquakes
Earthquake Insurance; Earthquake Injuries And Psychological Effects; Tsunami And the California Coast; Earthquakes: Is Control or Prevention Possible?
Earthquake Prediction in China
(by: G. Pararas-Carayannis, unpublished)
Historical Background. (The Great China Earthquake of 1556; The Haicheng Earthquake of February 4, 1975; The Tangshan Earthquake of 1976)
Earthquake Prediction in China. (Validity of Earthquake Prediction; Earthquake Prediction Research)
The Use of Animals in Earthquake Prediction. (Unusual Animal Behavior; Studies of Animal Behavior; Mechanisms of Animal Responses; Operational Network).
Major Earthquakes in Japan this Century
* SEPT. 1, 1923: Tokyo, 8.3, 140,000 dead.
* MARCH 2, 1933: Tsunami caused by quake off northeastern coast, 8.9, 2,990 dead.
* DEC. 21, 1946: Shikoku, western Japan, 8.0, 2,000 dead.
* JUNE 28, 1948: Fukui, western Japan, 7.1, 3,769 dead.
* MARCH 4, 1952: Hokkaido, 8.2, 8,233 dead.
* JUNE 16, 1964: Niigata, 7.5, 26 dead.
* MAY 16, 1968: Tokachi, eastern Hokkaido, 7.9, 52 dead.
* MAY 25, 1983: Northern part of Sea of Japan, 7.7, 104 dead.
* JAN. 15, 1993: Kushiro, Hokkaido, 7.8, one dead.
* JULY 12, 1993: Okushiri, Hokkaido, 7.8, more than 200 dead, some washed
to sea by tsunami.
* OCT. 4, 1994: Hokkaido and Kuril Islands, 8.1, 8 dead in Kuril Islands.
* DEC. 28, 1994: Hachinohe, northern Japan, 7.5, 2 dead.
* JAN. 17, 1995: Kobe, Western Japan, 7.2, more than 1,800 killed.
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THE BIG ONE (The Great California Earthquake) Introduction of a book by: George Pararas-Carayannis)
Table of Contents (To be added)
Earthquakes: What Are They?
Experiencing An Earthquake
The California Fault System
Historical California Earthquakes
Methods Used In Earthquake Prediction
The Big One: When and Where will the Big Earthquake Strike?
Determining Earthquake Risk
Reducing The California Earthquake Hazard
Earthquake Awareness And Preparedness
Protection Of Property from Earthquakes
Earthquake Injuries And Psychological Effects
Tsunami And The California Coast
Earthquakes: Is Control Or Prevention Possible?
SOUTHERN CALIFORNIA (Disaster Scenario )
A typical working day is about to begin in the South Central section of California. It is 7:50 on a sunny January morning, 1997. Traffic is already building up to its peak on Highway 101. All north-south routes in the area are jammed. Interstates 5 from the San Joaquin Valley and 15 through the Cajon Pass are loaded with commuters. The same is true for the freeways to the urban areas of Ventura, Los Angeles, Torrance, Riverside, and San Bernardino.
Yet, in exactly six minutes, this affluent, sophisticated, and highly populated region will suffer a catastrophic change. It is not the nature of this planet to be still. An endless continuity of change and movement must be sustained. A process that began many decades ago is nearing now its inevitable conclusion. A 250-mile segment of the San Andreas Fault, extending from Parkfield in Central California southward to San Bernardino, has gradually been forced into an unstable, strained position, held there by the strength of its rocks. Here, in this zone of weakness, 20 kilometers beneath the surface, this crustal block has reached the critical limit of its strength. The supporting rocks will rupture and the fractured blocks will slip across each other. This adjustment along this boundary of active tectonic plates marks a point in the movement towards a new equilibrium.
The pilot of a helicopter surveying the traffic checks his watch. It is 7:55 a.m. He reports to a local radio station that nothing unusual can be observed, no accidents, no stalled cars. Everything is going smoothly. It looks like a quiet morning. He asks the station to telephone his wife to tell her he'll be back by 10 o'clock to take her and the baby to the pediatrician.
At 7:56 a.m., a slight tremor is felt. Very gently at first. But it grows increasingly strong until the ground shakes violently for 20 to 25 seconds. In that infinitesimally minute fraction of time, the area that has taken years to develop is devastated.
The pilot in the helicopter looks below in distress. He tries to make radio contact again with his base. There is no response. Only silence. For miles around, wherever he looks, there is a horrific scene of carnage, chaos, and destruction. He stares in disbelief at the overpasses lying strewn on what remains of the highways. Demolished buildings form gigantic piles of rubble, entombing their dead and screaming occupants. On the highway below, an overturned tanker truck engulfs within its fiery cloak other vehicles around it as well as their trapped motorists.
The shaking stops. A momentary respite only. After 10 seconds, it resumes violently for another 30 to 40 seconds. Cars have piled up in tangled masses of wreckage, others have veered off the highways. Some are ablaze. Some have been buried by landslides. Hundreds of dazed and injured survivors stumble about hysterical, shocked, directionless.
It is now 7:59 a.m. In less than three minutes, thousands of people have been killed and thousands more are injured. Many more have been made homeless. Barely able to control his craft, the pilot is disoriented. Nothing he has seen in Vietnam, on television, or at the movies has prepared him for this. In terror and panic, he tries to find his home. He has flown over it many times before. The familiar landscape is almost unrecognizable. He finds space to land amidst uprooted trees in the park near his home. He runs toward the rubble that used to be his home. He crawls and claws his way over the masonry. There is only one thought in his mind, one prayer: please God, let them be alive, please God....He yells the names of his wife and daughter. There is no answer.
The violence of the shock is a warning to Civil Defense officials on duty, in the stricken area, that a major and possibly catastrophic earthquake has just occurred. At 8:01 am, the Office of Emergency Services in Sacramento, receives an urgent message from the Los Angeles County Civil Defense Warnings Center that a destructive earthquake has struck Southern California and that a state of emergency exists. The urgent message comes in on the California Warning System (CALWAS), the state's emergency telephone system. The announcement is heard simultaneously by all warning points throughout the state. Based on the urgency of the announcement, the Warning Controller on-duty at the headquarters of the Office of Emergency Services (OES) activates the state's Emergency Operations Center (EOC).
Following predetermined procedures, the staff of EOC alert the other OES staff, the Governor's Office, the California National Guard (CNG),the California Conservation Corps (CCC), the Emergency Medical Services Authorities (EMSA), the California Highway Patrol (CHP), and many other government and private organizations. The emergency announcements continue to go out to all warning points in the state via CALWAS, to all the warning points throughout the country on the National Warning Network (NAWAS)-a communications system operated by the Federal Emergency Management Agency (FEMA), and on the North American Defense Communications System (NORAD). One by one, County Civil Defense Centers in Orange, Riverside, San Bernardino and Santa Barbara report to the Sacramento Office, on the same emergency communications system, that a state of emergency exists and the activation of their EOCs.
Within a few minutes after the major shock ends, these officials begin converging on their operating centers in the affected counties. Fortunately, because of the time of the day, some are already at work. Officials from other participating federal and state agencies, trained to respond quickly to such emergencies, attempt to reach their operating centers. The severity of the earthquake is beginning to be realized.
The California Institute of Technology provides the Sacramento Office with the earthquake's magnitude and approximate epicenter. The earthquake has magnitude of 8 plus and its epicenter is in the mountains north of San Bernardino. Immediately, the Governor is informed by telephone of the disaster. Cancelling all business and functions the Governor phones the President at the White House to inform him of the disaster, and asks him for federal aid. The governor then makes arrangements to fly to the stricken areas by helicopter, despite the continuing aftershocks, to help direct the relief program.
EOC repeats the Cal Tech information on CALWAS, NAWAS, and NORAD. At 8:10, EOC activates the state's Emergency Broadcast System (EBS). EBS overrides functioning communications media, radio and television, providing the public with preliminary information on the earthquake, its epicenter, magnitude, and initial, unconfirmed reports of the extent of the damage, as provided by local radio operators. The state's EBS gives additional information and issues instructions to survivors on how to maximize their safety and minimize dangers of post-earthquake effects such as those caused by aftershock fires, gas explosions, and tsunamis. Functioning television and radio stations broadcast special announcements and local newscasters relay information as it is reported.
The EOC in Sacramento initiates communications tests with all civil defense centers in Los Angeles; Kern, Orange, Riverside, San Bernardino, Santa Barbara, and Ventura Counties, in the region that has been afflicted. Most are functioning, but some are only on emergence radio communications and emergency power. Orange County's EBS, which was down temporarily, resumes broadcast when an emergency generator is reactivated. Most communication facilities throughout these counties have failed. Radios are the only operable communications medium. There are numerous and unconfirmed reports from amateur radio operators that are relayed to the public by local stations, but these reports are conflicting and create additional confusion.
It is now 8:11. The National Earthquake Information Center (NEIC) in Boulder, Colorado provides updated earthquake data from its worldwide network. The magnitude of the earthquake is 8.3 and the epicenter is in the vicinity of the Tehapachi Mountains. The Pacific Tsunami Warning Center (PTWC), in Hawaii and the Alaska Tsunami Warning Center (ATWC) via NAWAS confirm the magnitude and epicenter of the earthquake.
Brief and incomplete reports from the police, fire departments, and CB operators provide preliminary assessments of the damage and assistance needed. County radio transmissions are monitored and received at Regions I and VI of the OES. One by one the counties report on the disaster.
A great deal of destruction and numerous deaths and injuries are reported from all areas in the southeast section of Kern County. The telephone service, electricity, gas, and water have been disrupted in Bakersfield. Massive rockslides are reported along Interstate 5 at Grapevine. Highway 99 and I-5 have been heavily damaged from Corpus Road to the south. Poisonous chemical spills are reported from Wheeler Ridge area. Finally, from the southeast section of Kern County, severe damage and a high number of casualties have been reported. Efforts to make contact with the east of the county and with the mountain communities of the Woods and Pine Valleys have failed.
The Los Angeles County's EOC on Eastern Avenue, utilizing helicopters from the sheriffs department and the L.A. County Fire Department, has begun an aerial reconnaissance of critical facilities and areas. The hardest hit areas are those in the north, particularly Lancaster, Palmdale, Quartz Hills, and Gorman. These have been totally devastated. High casualties are reported. The Los Angeles /Long Beach areas have been seriously damaged. Similarly, central Los Angeles has been seriously impacted and all the freeways are blocked with heavy traffic or abandoned vehicles. At Los Angeles International Airport, critical damage to the control tower and to all the major runways have brought all operations to a halt. All airports are reported to be closed for evaluation of runways and structures supporting the air traffic operations. Thousands of people are left stranded. Fires are reported from the general area of the harbor where the refineries are located. Hospitals in the Newhall area have been damaged and medical facilities are inadequate to treat the vast numbers of injured. The Los Angeles Aqueduct has been severely damaged and a great deal of water can be seen escaping. Traffic is worse on Interstate 405, and the I-55 last Main Street overpass has collapsed with several cars buried underneath.
In Orange County, a landslide at Green River has Highway 91 blocked in Santa Anna Canyon. The bridge to Balboa Island has been destroyed. Traffic has been completely stopped on Interstate 405. There are reports of injuries and property damage in the Santa Anna area. Many have been trapped and are injured in the County Administration Building. The death toll in the county is high and increasing. Medical facilities at Irvine Medical Center are reported as being extensively damaged and barely functioning. The San Onofre Nuclear Generating Plant has declared an emergency as its cooling system has been partially destroyed. Personnel are working frantically to shut the plant down and to activate the secondary cooling system to reduce reactor core temperatures that continue to rise. Chemical spills at Westminster are also causing concern.
In Riverside County, the EOC reports failure of all communications. Sketchy reports indicate that parts of Riverside and Corona and other communities along the Santa Ana River have been razed to the ground. However, Palm Springs and Hemet have escaped with only light structural damage. In the worst affected areas, the casualty list is high and growing. Initial reports indicate that over 300 people have died, with thousands more injured. In some areas, looting is taking place. Fires are burning uncontrolled in many parts near the industrial areas. The bridge over the river on Highway 61 has collapsed. The overpass of Highways 60 and 91 have collapsed as well.
In San Bernardino County, heavy damage has occurred at the Atchison, Topeka, Santa Fe, Union Pacific, and Southern Pacific railroads due to numerous overpass and bridge failures. A freight train has been derailed between Cajon Pass and Whitewater. Norton Air Force Base and Ontario Airport are nonoperational. High voltage lines have fallen on Highway 191 at Colton. Traffic has been halted at all the intersections of I-5 with I-15 and the I-10 interchange northwest of San Bernardino City. Extensive damage is reported throughout the county except in the mountain communities of Big Bear and Arrowhead where damage is moderate. Several thousand homes have been damaged or destroyed with unknown damage to business and industrial complexes. The death toll is mounting with serious injuries of a thousand or more. St. Bernadine's, Cino General, Doctors Hospital-Monclair, Redlands Community Hospital, and the County Medical Center have all been damaged and are unable to cope with the vast numbers of injured.
From Santa Barbara, there are reports of massive landslides at Gaviota Pass on Highway 101 at the San Marcos Pass, isolating the north county area from the south. All attempts to make contact with Quyama Valley have failed. The dam at Twitchell Reservoir has suffered structural damage and water is leaking from it. Telephone, electricity, and water services have been totally disrupted. No specific reports of deaths or injuries have been received.
Ventura County has been devastated, and a high casualty rate is indicated. All telephone, communications, electricity, gas, and water lines have been disrupted. Liquefaction of the ground has caused extensive destruction at Ventura, Oxnard, Thousand Oaks, San Pedro, Long Beach, Huntington Beach, and along the entire length of the Santa Ana River. Isolated pockets of liquefaction have also occurred at Inglewood, Pacific Palisades, Beverly Hills, and San Fernando. Bridges have collapsed along the Santa Clara River at Highways 101, 118, and 33. Massive landslides have closed Routes 123,33 north of Ojai, and 150. Industrial fires are burning at Ventura and Newbury Parks. Many schoolchildren have already been trapped at one school in Ventura and many others are trapped in school buses. Some children are reported as roaming aimlessly in the streets. Hundreds of fatalities and injuries are reported. Urgent radio transmissions indicate the need for helicopter transport of casualties.
This is only a partial scenario of what could happen if an earthquake of magnitude 8 or greater on the Richter scale struck southern California during the morning rush hour with its epicenter in the mountains northeast of Los Angeles. The scenario is based partially on an earthquake readiness exercise conducted by the State's Emergency Services Office in 1981 and on a reconstruction of the 1857 Fort Tejon earthquake.
If a large earthquake strikes during rush hour southern California around the Los Angeles metropolitan area, similar to the 1857 earthquake, it would kill at least 3,000 to 15,000 people and hospitalize 12,000 to 50,000. Landslides would block highways and all lifeline support systems will be heavily damaged. Multiple other earthquake related disasters would increase the death toll and the destruction.
If a similar earthquake occurred now in the Bay area during the peak of the rush hour, as many as 11,000 to 12,000 people could die and at least 45,000 to 50,000 might be hospitalized. Officials in California have been forewarned by scientists about the strong probability of a large earthquake occurring before the end of the millennium. Scenarios of destruction and emergency plans of action are in preparation in anticipation of such a catastrophe.
Most Californian residents live with the knowledge that earthquakes, at least minor ones, are a part of their lives. Their homes and places of work are mostly of unknown earthquake resistance. As yet, insufficient thought has been given to the imminent prospect of an earthquake of devastating proportions. The responses of many are unrealistic or fatalistic. The former do not believe a serious earthquake will happen in their lifetime, while the latter feel that even if it does, nothing can be done about it.
Neither avoidance nor resignation will lower the casualty list or save lives. Awareness and preparedness will. Among the many misconceptions on the subject, one of the commonest is that only the most destructive earthquakes kill directly. In fact, most deaths are caused by structures falling and collapsing, such as buildings, dams, and bridges. Gas lines rupturing cause fires. Other hazards may include landslides, or local tsunamis that would only affect the coastal areas.
Earthquake-related fatalities, injuries, and property destruction can be avoided or minimized by correct planning, construction, engineering, and land utilization. Education programs that teach earthquake awareness and safety measures should be taught throughout the state in schools, colleges, at home, and at the place of work.
Structures can be built that are earthquake resistant. Many buildings and homes can be reinforced at a small cost to the individual, company, or state to withstand the effects of an earthquake. Lowering water in potentially vulnerable dams would also help to limit the destruction. Nuclear power plants and other hazardous enterprises should not be permitted to function in areas that are earthquake-prone. Regardless of the expense, Californians should view any earthquake preparedness and planning as their most valuable asset and investment. Preparations made in the next few years will largely decide whether Californians die in or survive the Big One.
MAJOR CALIFORNIA FAULTS
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Earthquake Prediction in China
by : George Pararas Carayannis (Unpublished)
China is located in one of the most active seismic regions of the world and has been plagued by numerous destructive earthquakes during its long history. The most significant of these earthquakes, in terms of lives lost, was that which occurred in 1556. In the last twenty years China has experienced the second most destructive earthquake in its history. The following is a brief account of the 1556 and the recent 1975 and 1976 earthquakes.
The Great China Earthquake of 1556
The worse natural disaster in recorded history, at least in terms of lives lost, was caused by an earthquake in Hausien in the Shensi Province of China in 1556. The earthquake devastated 98 counties and eight provinces of Central China. The destruction spanned an area of 500 miles, and in some counties the average death toll was 60 percent of the population. A total of 830,000 people lost their lives, most of them from the collapse of poorly constructed houses. The magnitude of this earthquake has been estimated to be from 8.0 to 8.3 on the Richter scale.
The Haicheng Earthquake of February 4, 1975
On February 4, 1975, Haicheng, a town with about 100,000 inhabitants in the Liaoning Province of northeast China, was struck by a 7.3 magnitude earthquake. As early as 1970, the State Seismological Bureau, had identified the Liaoning Province as an area of high earthquake risk. Based on studies of precursor events and unusual animal behavior, a warning was issued by local authorities. Thus, when the earthquake struck on February 4, there were few lives lost as most inhabitants had evacuated to safer places. However property damage was high.
The China Earthquake of 1976
No other earthquake in this century has been as catastrophic or has claimed as many lives as the great earthquake that struck the city of Tangshan, in Northern China, on July 28, 1976.
Tangshan, a thriving industrial city with one million inhabitants, is located only about 95 miles east, and slightly south, of Beijing. Although the region had experienced moderate seismic activity in the past, the city of Tangshan has been built on unstable, alluvial soil. To make matters worse, The city is located in the center of an area with major crustal faults on four sides. Furthermore, a 25-mile long fault passes through Tangshan, where only few of its structures are earthquake-resistant.
In the early morning hours of July 28, while the city was asleep, the magnitude 8.0 earthquake with its epicenter right on the city broke a five-mile section of the fault. Along the west side of the fault the land moved five feet northward in relation to the land on the east side. The east block tipped downward at the northern end of the break, and upward toward the south end. Over a four-by-five mile area the devastation of the city was nearly total. The force of the quake motions were so strong that people reported being thrown in the air. Within seconds, thousands died. Property destruction was unbelievable. Bridges, railroads, homes, factories were completely leveled.
In the harbor city of Tientsin, 60 miles to the southwest, and in Beijing to the west, the quake jolts forced thousands of frightened people into the streets seeking refuge from aftershocks.
The extent of the destruction and number of deaths in Tangshan and elsewhere in China was never disclosed officially. However, based on the density of population, it was fairly accurately estimated that there were at least 655,000 people dead, and 780,000 injured. These figures make the 1976 Tangshan earthquake, the second worse earthquake in recorded history. The most destructive earthquake ever, as reported earlier, occurred at Hausien in China's Shensi Province in 1556.
MAJOR TECTONIC ZONES OF CHINA
Earthquake Prediction in China
In order to reduce the risk of an earthquake and reduce and mitigate its effects, it is necessary to predict where and when a future, large earthquake may occur. For example, it would be important to know when such an earthquake will hit, where it will strike, and what the level of its destructiveness may be. Earthquake prediction at the present time is not an exact science, and forecasts of earthquake occurrences have not been very accurate. Presently predictions are given in statistical terms. For example, when a prediction is made that :here is a 90% chance that an earthquake will occur in the next 50 years", it does not mean that this earthquake cannot happen tomorrow or it may not be delayed by 50 years. Thus, present predictions are not within a reasonable time frame that can be of usefulness to planners, policy makers, and those in government that deal with public safety.
To understand earthquake prediction, three different time frames have been assigned by scientists: long term, intermediate and short-term predictions. Long term prediction involves a time frame of a decade or more and can only be general and with very limited usefulness for public safety. Intermediate term prediction would fall into a time span of a few weeks to a few years, and again it would not be of great practical usefulness. It is the short-term prediction, that is specific information on the time and location of an earthquake given within days, weeks, months - not years - that would be useful for any kind of public safety and evacuation.
Several specific geophysical, geological, and chemical methods are presently used for earthquake prediction. To the list of geological and geophysical events and precursors we should add one more method that has been used with much success in China: that is the monitoring the behavior of animals before quakes.
Validity of Earthquake Prediction
It was in the early evening hours of February 4, 1975, when an earthquake of magnitude of 7.3 struck the densely populated town of Heicheng, in the Liaoning Province, in northeast China. As expected, because the magnitude was great and the area highly populated, damage to Haicheng and to neighboring towns was extensive. However, what was different about this earthquake is that very few lives were lost. The reason for the low death toll was that the occurrence of this earthquake had been successfully predicted.
As early as 1970, the State Seismological Bureau in China had identified Liaoning Province as a high earthquake-prone area. A short term earthquake prediction was given to the population in the Haicheng area as early as mid-January 1975. This prediction was based on a number of geophysical observations of precursor events as well as abnormal animal behavior. When the earthquake struck, the people of Haicheng and neighboring towns had been warned, and the warning saved many lives and averted a disaster of major proportions. Four other disastrous earthquakes were predicted by Chinese scientists during the 1975/76 period, giving hope that earthquake prediction was finally possible.
When a great earthquake with magnitude of 7.8 struck the city of Tangshan on July 28, 1976, at least 655,000 people died and 780,000 more were injured. There was no prediction for this earthquake, and therefore no warning. Hope in the accurate predictability of earthquakes evaporated. Although precursor events had been observed and geophysical and geochemical anomalies had been detected, these precursor events occurred over a very widely-spread area making it extremely difficult for scientists to focus on any particular region and thus issue a short-term prediction, or a warning. There were remarkable differences between precursor events of this particular earthquake and those of other predicted earthquakes. Furthermore, no significant foreshocks were observed. The examples given illustrate the validity of earthquake prediction at the present time. However, progress is being made which may lead to better predictions.
Knowing that an earthquake will occur in any particular region is not sufficient. There is no doubt that earthquakes can occur anywhere along any of the numerous faults of China. To provide predictions too far into the future would be totally impractical. Thus, only the short-term predictions should be relied upon, since longer term predictions could have greater social and economic effects, particularly if they are false. For predictions to be of usefulness they would have to specify time, place, and magnitude of a forthcoming earthquake with sufficient precision and level of confidence to be practically useful. Studies of earthquake recurrence frequency. although useful from a statistical point of view, cannot be used with sufficient confidence for a prediction. For a prediction to be valid, it has to be sufficiently precise, and supported with a great deal of research and instrumentation. However, it is difficult, if not nearly impossible, to instrument all the faults and to monitor all the different parameters used for prediction.
Therefore, until such time as earthquake prediction becomes a more exact science, it might be best not to issue any predictions. Hopefully, it is only a question of time before effective methods can and will be used for reliable predictions. Until then, and until the complex interactions of the behavior of earthquake faults is understood, it would be best not to utilize predictions for public evacuation. But this does not mean that preventive measures cannot be taken to ensure the safety of the public and the protection of property. With proper planning and public awareness, the effects of the earthquake hazard can be mitigated.
Earthquake Prediction Research
Presently what is called prediction is not really that. It is simply scientific research on understanding the workings of earthquakes. There is not sufficient historical data on which to base the number of hypotheses that have been proposed for earthquake predictions and, therefore, there is no way to judge the ultimate success or failure of such predictions. It would be difficult to explain to the public the difference between scientific research studies and actual predictions. There will be difficulty in understanding and it would be even more confusing.
For example, the present research efforts are directed toward the prediction of the numerous small earthquakes (magnitude 3 and 4) that occur frequently. By predicting the smaller earthquakes and by understanding the earthquake process that is taking place, it is believed that the long-term goal of predicting large, destructive earthquakes will be achieved. Thus researchers install dense nets of seismograph stations along active sections of active faults. Such networks are used to establish detailed studies of the pattern of seismic activity in respect to both the location of the earthquakes and the time of their occurrence. By so doing, researchers attempt to identify "gaps" or anomalies, in the pattern of seismic activity. Numerous types of instruments and methods are used for earthquake prediction. These instruments measure tilts int the ground's surface, as well as changes in the magnetic field near active faults . Usually these changes precede the occurrence of some earthquakes.
In addition to the field investigations, laboratory and theoretical studies are also being carried out by governmental organizations and various universities in China and throughout the world. These investigations include studies of the mechanism of earthquake faulting of various rock types under conditions of high temperature and pressure, and detailed investigations of ground swelling, otherwise known as "dilatancy", which precede an earthquake. Computer simulations of the conditions of the earth are being made as another means of obtaining patterns of earthquake processes in the hope of learning more about properties of the earth that control earthquakes.
The Use of Animals in Earthquake Prediction
Research being carried out in China has indicated that recognition of unusual animal behavior in a systematic way can lead and be used, in conjunction with other methods, as a means of predicting large and potentially destructive earthquakes. The following are examples of observed unusual animal behavior before major earthquakes occurred.
Unusual Animal Behavior
In 1920, the largest earthquake to hit China with a magnitude of 8.5 occurred in Haiyuan County, Ninghsia Province. According to reports of eyewitnesses, prior to this earthquake, wolves were seen running around in packs, dogs were barking unusually, and sparrows were flying around wildly. It is reported that prior to the 6.8 magnitude earthquake in 1966 in Hsingtai County, Hopei Province, in Northern China, all the dogs at a village near the epicenter had deserted their kennels and thus survived the disaster.
Prior to the earthquake of July 18, 1969, (magnitude 7.4) in the Pohai Sea, unusual behavior was observed in seagulls, sharks, and five different species of fish. Based on observations of unusual behavior of giant pandas, deer, yaks, loaches, tigers and other animals, a warning was issued at the Tientsin People's Park Zoo, two hours before the earthquake struck.
The Chinese began to study systematically the unusual animal behavior, and the Haicheng earthquake of February 1975 was predicted successfully as early as in mid-December of 1974. The most unusual circumstance of animal behavior was that of snakes that came out of hibernation and froze on the surface of the earth. Also a group of rats appeared. These events were succeeded by a swarm of earthquakes at the end of December 1974. During the following month, in January 1975, thousands of reports of unusual animal behavior were received from the general area. Local people saw hibernating snakes coming out from their holes and into the snow. In the first three days in February the activity intensified even more and unusual behavior of the larger animals such as cows, horses, dogs and pigs was reported. On February 4, 1975, an earthquake of magnitude 7.3 struck the Haicheng County, Liaoning Province.
More instances of unusual animal behavior were reported. A stock breeder in northern China, feeding his animals before dawn on July 28, 1976, in the area of the Kaokechuang People's Commune, approximately 40 kilometers away from the city of Tangshan, reported that his horses and mules instead of eating were jumping and kicking until they finally broke loose and ran outside. A few seconds later, a dazzling white flash illuminated the sky. Tremendous rumbling noises were heard as a 7.8 magnitude earthquake struck the Tangshan area.
Other reports of unusual animal behavior prior to the occurrence of earthquakes have been reported in the literature and in books. Such unusual animal behavior included goats refusing to go into pens; cats and dogs picking up their offspring and carrying them outdoors; pigs squealing strangely; chickens dashing out of the coops in the middle of the night; fish dashing about aimlessly; and birds leaving their nests. It has also been reported that zoo animals refused to go back into their shelters at night; snakes, lizards and other small mammals evacuated their underground nests; insects congregated in huge swarms near the seashores; cattle sought higher ground; domestic animals became agitated; and wild birds left their usual habitats.
Surveys done in China show that the largest number of cases of unusual animal behavior precede the earthquake, particularly in the 24 hours before it strikes. In other parts of China where major earthquakes have been preceded by foreshocks, unusual behavior in rats, fish, and snakes were observed as early as three days prior to the earthquake, but continuing to several hours, or even a few minutes before.
Studies of Animal Behavior
Throughout China's long history, unusual behavior has been observed in every kind of common animal. Most of the behavior falls into the category of unusual restlessness and disorientation.
Since animals have the capability of acting as predictors of earthquakes, the Chinese scientists have carried out surveys of animal behavior variations prior to earthquakes. A team of scientists including biologists, geophysicists, chemists, meteorologists, and biophysicists conducted a survey in the Tangshan area and in 400 communes in 48 counties around it after the 1976 earthquake. The scientists visited a number of places that were hit by other destructive earthquakes and, through interviews and discussions with local people, collected information on over 2,000 cases of unusual animal behavior occurring prior to an earthquake. The majority of the reports involved domestic animals. Based on this survey a preliminary report was prepared by the Chinese identifying 58 kinds of domestic and wild animals that had demonstrated unusual behavior.
The principal focus of research work in China has been on the behavior of pigeons. Biological studies on pigeons determined that a hundred tiny units exist between the tibia and fibula on a pigeon's leg. These nerve units are connected to the nerve center, and are very sensitive to vibrations. Scientists determined that prior to an earthquake of magnitude 4.0, which occurred in the area of the study, fifty pigeons that had severed connections between the tibia, fibula, and the nerve centers, remained calm before the earthquake, while those with normal connections became startled and flew away.
Because of the success in monitoring unusual animal behavior for the prediction of certain earthquakes, the Chinese, who have pioneered this work, have looked into ways to construct instruments that would duplicate the sensory organs of animals which were able to monitor, and sense, stimuli preceding an earthquake. Researchers found it very difficult to understand the mechanism of response stimuli. Physical or chemical stimuli come out of the earth prior to an earthquake and these must be the stimuli that animals can sense. For example, dogs may be able to hear the microfacturing of rocks a few milliseconds before a quake shock reaches the surface. Electromagnetic changes in the earth prior to an earthquake may be sensed by such animals as sharks and catfish which have low or high frequency receptors and sense such changes actively or passively. Also such electromagnetic field changes could be affecting migrating birds and the navigational ability of fish.
Mechanisms of Animal Responses
What is the sensory mechanism of animals that controls their responses to changes related to an impending earthquake? As mentioned earlier, the behavior of an animal might be subject to changes in the magnetic field preceding a major earthquake and such changes may be sensed by energy transfer at the electron level which, in turn, cause changes in the cellular behavior, or response. The living cell is essentially an electrical device and a micromolecular structure, and the sensory organs are all interconnected. Electromechanic changes occurring prior to the occurrence of a large earthquake may be sensed by certain animals and filtered, then instinctively interpreted. Thus animals may have the means and sensitivity to sort out and discriminate the threatening precursory signals of an impending earthquake, thus activating a behavior pattern for survival.
These precursory electromagnetic or electromechanic changes which precede an earthquake, although mixed with background noise, must be filtered by animals and coordinated through their sensory response to the total environment. Thus, behavior is determined by the sensitivity of the different component parts of the living system to the surrounding medium. Experiments with new instruments and electronic solid state sensors are being used now to determine animal response to impending catastrophic occurrences.
The benefit from such research would be in duplicating the sensory responses of animals to construct equally responsive instruments that can record or monitor these precursory changes. Thus, observing and studying animal behavior could lead to better earthquake prediction instrumentation.
Since China considers such information on animal behavior vital to prediction, it established in 1968 its first experimental station for earthquake predictions making use of biological observations. This experimental station was established in Hsingtai Province. Other similar stations were set up in 1971 in Aksu, Sinkiang Province, where earthquakes were expected to occur. Since 1971, the Chinese have established an operational network in different communes or counties. Whenever unusual events occur and are reported by numerous observers, these are evaluated as a way of predicting earthquakes. So far, by this means, two major earthquakes have been predicted. This is easy for the Chinese since 80 percent of the population live in farming areas that are in close association with animals which can be observed readily. It is a little more difficult for people living in urban areas to observe similar animal behavior.
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