原文: Earthquake Prediction in China - Monitoring Animal Behavior

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.

China's Seismic Zones

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, Ninghxia 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.

Operational Network

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.

译文: 地震预测，动物也是“预报员”

地震预测的有效性

      1976年7月28日，唐山发生里氏7.8级大地震，造成至少65.5万死亡，78万人受伤。因为这场地震没有任何预报，因此也没有警告，想要准确预测地震的希望成为泡影。尽管观察到了地震前兆现象，也监测到了物理和化学上的异常现象，但是由于这些前兆发生的地域过于广泛，使得科学家无法精确预测并发出警告。这次大地震的前兆与以往地震的和被预测到地震的前兆有很大的不同。不仅如此，科学家们没有观测到任何前震。上述例子都说明了当前地震预测的有效性，然而，科学家们仍在不断努力使预测工作更为准确。

    仅仅知道地震会在什么地方发生是不够的。毫无疑问，中国领土上有太多断层，这些地方随时会发生地震，预测太过遥远的地震显得很不实际。所以，只有短期预测可依靠，因为长期的预测会对社会和经济产生更大的影响，尤其当预测出现了错误时，这些影响将更大。要使地震预测真正发挥作用，预报必须有绝对的精确，而科学家则必须有充分的自信指出地震的时间、地点及震级。但对于地震再次发生频率的研究，从统计学的角度看很有用，但这不能用于预测地震。为使预测有效，预测必须足够精确，有很多研究和仪器数字的支持。然而，如果想要用仪器测出所有的问题，监测各种各样数据来预测地震，就算不是不可能，那也是极为困难的。

    因此，在地震预测成为一门精确科学之前，不做任何预警是最好的办法。总有一天我们可以并将用有效的方法作出可靠的预测，这只不过是时间的问题罢了。到那个时候，等我们对地震断层之间复杂的相互作用充分了解之后，最好就不要用预测来进行撤离了。但这并不意味着我们不能做防御措施来确保社会和财产的安全。只要有适当的计划和公众意识，地震的危害就能得到降低。

地震预测的研究

    现在所谓的预测并不是实际意义上的预测，这只是单纯的依靠科学研究对地震的物理情况的进一步的理解。历史上的数据并不足以确定地震的预测是否准确，因此，谁也无法确定预测是否准确。想要向公众解释清楚科学研究和实际上预测的区别并不是一件容易的事，理解上的困难会更令人更困惑。

    举个例子，现在的地震研究旨在预测出比较频繁的小地震（里氏3级至4级之间）。人们相信，通过预测这些小地震，了解地震的具体过程对预测大地震、毁灭性地震这一长远目标能起到很大的作用。因此研究者们在地震活跃区大量安置了地震监测网点，形成一个监测网络，通过监测地震活动的地点及持续时间来对地震进行具体的研究。通过这种方法，研究者们就可以了解地震活动的异常现象。他们还用各种各样的仪器和方法，通过测量地震前发生的地球物理上的变化，如地表倾斜度和活性断层附近的磁场变化，对地震进行预测。

    除了对地面的监测，政府机构和世界各地的大学也从实验和理论的角度进行研究。这些调查包括不同岩石在高温高压下的地震断层原理和对地隆（即膨胀性岩石）这种预示地震的现象的具体调查。人们还通过计算机模拟地震发生时的情景，期望通过这一方法了解更多引起地震的土壤的性质。

动物反常行为预测地震

    中国调查显示，系统的观察动物的异常行为结合其他方法，也可被视为一种预测大规模毁坏性地震的方法。下面要说的人们在大地震之前观察到的动物的异常行为。
































动物的反常行为

    上个世纪20年代，宁夏省海原县发生里氏8.5级大地震，为史上之最。有目击者称，那次地震之前，他们看见大批狼群四处疯跑，狗狂叫，麻雀乱飞。还有报道称，1966年河北省邢台市发生6.8级地震之前，位于震中的所有狗都弃舍而去，因而存活了下来。

     1969年7月18日在渤海发生7.4级地震。震前，人们看到了海鸥、鲨鱼和其他五种动物的异常行为；在天津动物园人们还注意到了大熊猫、鹿、牦牛、泥鳅、老虎和其他动物的异常行为。

    由于中国开始对动物异常行为进行系统的研究，1975年2月发生在海城地震早在1974年12月中旬就已被成功预测到。那一时期最不寻常的事情就是蛇从冬眠中出来睡在土壤表面上，同时还出现了很多的老鼠，这些都是在12月末发生的一系列地震之后发生的。而在接下来的一个月，也就是1975年1月，当地就有数千个动物行为反常的事件发生。当地百姓看见冬眠中的蛇从洞里爬出来钻进雪里。在2月份的前三天，这种异常事件变得尤其多，还有很多大型动物诸如牛、马、狗、猪等也行为反常。然后在1975年2月4日，辽宁省海城市发生7.3级地震。

    还有更多此类事件。1976年7月28日，距离唐山大约40公里之外的一个人民公社里，有一名牧人正在喂养牲畜。但是马和驴不但不吃草，反而又跳又踢挣脱出了绳子向外面跑去。几秒钟之后，一道耀眼的白光照亮了天空，紧跟而来的就是巨大的隆隆声。唐山发生7.8级地震。

    在文学作品中和书中也有类似的例子。比如说：山羊不愿进羊圈；猫狗叼起它们的崽往外跑；猪反常的叫；鸡在半夜的时候拼命的冲出鸡笼；鱼烦躁的四处游；鸟离开巢穴。还有报道称动物园的动物晚上都不愿回窝睡觉；蛇、蜥蜴等小型哺乳动物晚上都不愿再回它们在地下的窝；昆虫大量的聚集在海边；牛群往高处走；家畜变得烦躁不安；野生鸟类离开它们平常的居所。

    有调查显示，在动物异常行为的比例中，地震前，尤其是地震前24小时的异常行为占据了很大的百分比。在中国其他地区，大地震之前通常伴有前震，那儿的老鼠、鱼、蛇等动物的异常行为则早在地震发生三天前就有所表现，这种现象会一直持续到地震前几个小时甚至几分钟。

动物行为的研究

    纵观中国历史，每一种动物在地震前都有异常举动，而大多数情况下都显示为异常的烦躁不安和迷失方向。

    因为动物有预测地震的能力，中国科学家就动物在地震前的变化做了不少研究。在唐山大地震之后，一支由生物学家、地球物理学家、化学家、气象学家和生物物理学家组成的科学家队伍在唐山及周边400家市镇和48个县作了调查，他们走访了遭受过其他大地震的地区，与当地百姓进行交谈和讨论，收集了2000余个关于地震前动物反常的例子，而大多数例子涉及的是家畜。通过这一调查，科学家们可以初步确定有58种家养的和野生的动物在地震前表现出了异常反应。

    中国科学家们主要将研究的重点放在了鸽子上。生物研究指出在鸽子腿上的胫骨和腓骨之间有100个微小的神经元，这些神经元连至神经中心，对震动十分敏感。科学家发现，在实验区发生了4.0级地震之前，50只鸽子隔断了胫骨、腓骨与神经中心的连接使之在地震前保持镇定，而那些没有这个能力的动物则因为受惊而四处乱飞。

    因为中国在观察动物行为预测地震方面作为先驱且颇有成效，我们正寻求方法来制造仪器使其能像这些动物有敏锐的感觉器官，能够监测、感觉到地震并作出反应。但科学家们发现想要了解这种反应刺激的机理并不是一件容易的事。通常在地震前的物理和化学上的刺激动物是能够感受到的。比如说，狗也许能在地震到达地表几毫秒之前听见石头间的微小动静。鲨鱼、鲶鱼这些具有低频或高频感受器的动物也许能在地震来临之前感受到电磁的变化并作出积极的或被动的反应。这种电磁场的变化同样还会影响正在迁徙的鸟和鱼的导航能力。

动物地震反应的原理

    这些动物到底拥有什么样的感觉机能使得它们能对地震到来前的变化作出反应呢？如上文所说，动物的行为可能是由于地震前磁场变化引起的，而这些变化会通过电子的能量传递被感知，进而引发了细胞行为，或者说是反应。一个活细胞其实就是一个电子装置和一个小分子结构，而感官组织是互相连接的。大地震前的这些生理上的变化可能会被一些动物感觉到，然后本能的作出反应。因此动物通过这个方法和敏感觉察到地震前的危险信息，作出异常的行为用以求生。

    尽管有背景噪声（与电力线或变电站的无线电干扰出现与否无关的系统总噪声）的干扰，但是动物仍能感觉到地震来临之前的电磁变化以及自身的变化，并调整自身的行为来适应整个环境。因此，是它们生命系统的不同部位对周围媒介的变化使它们作出异常反应。现在科学家们已经采用新的仪器和固体电子传感器对动物进行实验，观察它们在大灾难到来前的反应。

    这些实验旨在利用动物的感官反应制造出同样具有次感觉的仪器以记录和监测地震前的变化。这样，通过对动物的观察和研究，我们就能制造出更好的仪器预测地震。

地震监测网络

    在认识到观察动物的异常行为对预测地震至关重要之后，中国于1968年在邢台市建立了首个通过生物观察来预测地震的观察站。1971年，因为预计新疆阿克苏地区会发生地震，因此在那儿也建立了类似的观察站。从1971年起，中国在不同县市建立的观察站已经形成了一个监测网络，人们一旦发现异常事件就上报，这也成为了预测地震的方法之一。到现在为止，人们通过这个方法已成功预测了两次大地震。中国80%的人口生活在农村，可以随时注意到家畜的异常举动，因此这种方法就显得简单易行；但是这一点对于生活在城市里的人来说就有点困难了。