It is not difficult to predict the possibility of a future earthquake, which can be done by measuring the stress and plasticity of rocks or monitoring micromovements in faults. In countries located between active tectonic continental plates, an earthquake might strike at any moment – yet it is impossible to say when and where. Although it is possible to measure stress, pressure, and vibrations using devices like seismographs, it is not possible to predict which plate will break when and with what force. We may not know when it will strike, but still we can be prepared for it and minimize the destruction. Erecting high-rise buildings on a ground which is not solid enough and with insufficient construction techniques is certainly not a good preparation for earthquakes.

Although humans cannot predict earthquakes in advance, there has been an increase in the number of laboratory studies into animals predicting earthquakes. This isn’t a new phenomenon: former generations are known to have made extensive observations about the matter, yet none were presented as scientific evidence that could withstand scrutiny. Evaluated objectively, these conclusions are not completely irrelevant or groundless; however, they never confidently predict the time, place, and force of an earthquake.

Numerous sources include observations about strange pre-earthquake behavior of many domestic animals such as dogs, cats, cattle, chickens, and rabbits, as well as non-domesticated animals like insects, birds, and various sea creatures. But such behavior could well stem from other factors such as hunger, inter-group competition, and other adverse conditions.

Ants and snakes

Ants and snakes deserve special emphasis thanks to their anatomical and physiological features. Although both species are somewhat deaf to the sounds coming from the air, evidence suggests that they might be able to detect sounds, electromagnetic radiation, and gas emissions coming from the depths of the Earth. In a remarkable story in the Qur’an (chapter al-Naml), an ant detects Solomon’s approaching armies and warn other ants not to be crushed. One may think here of an allusion to the ant’s skill to detect the vibrations generated by the clopping of the horses.

Monitoring ant behavior closely could help with earthquake preparations. If there is a significant increase in the number of ants at one location; if they have left their nests and move differently; or if there is an increase in the number of dead ants for no obvious reason, then an earthquake might be imminent.

A body like an electronic communication center

Despite its tiny body, the ant has a variety of sensory organs. It’s almost as if it were a fully-equipped center for picking up and evaluating pulses. The ant has three small eyes on its head that enable it to detect the intensity and polarization of light, as well as compound eyes on the sides of its head, each with multiple lenses providing 180 degrees of vision. The pair of antennae on its head, filled with receptors for taste, smell, and humidity, make it possible to detect all types of chemicals in the environment and are more important than the ant’s eyes. Some types of ants are almost blind and rely completely on their antennae.

Desert ants have about one thousand lenses in their eyes, while we humans have one in each eye. Rüdiger Wehner and his colleagues at the University of Zurich discovered that each ant eye has 80 lenses specialized in detecting polarized light across the ultraviolet range of the spectrum. Each lens focuses on a different point in the sky. One lens, for example, receives light from 180 degrees, another from 270 degrees, and so on. Even if they cannot see the sun, they can locate it thanks to the specialized cells in their eyes. This enables them to find the right compass direction and to determine the distance they have covered.

Sensory hairs

Especially mind-boggling about ants is the keenness of the special sensory hairs in various regions of their exoskeleton (Figure 1). The hairs on the antennae and the underside of the legs are particularly sensitive. Each hair is attached to the exoskeleton through a delicate joint and moves with the slightest vibration. The sensory cell under the hair is connected to a nerve fiber, and even a slight vibration of the hair causes a chemical exchange signal by which the ant “feels.” Some of these hairs respond to sound waves. These hairs group in certain regions (Figure 2). Considering the complex sensory organs on their head, the fact that they can perceive more than a million chemical and light signals, that the sensory hairs under their mouth and on their legs can send signals, and that they have a brain with as much as 500,000 nerve cells, it seems reasonable to assume that ants can detect an earthquake before it strikes.

A group of scientists from the University of Duisburg-Essen led by Gabriela Berberich studied more than 15,000 red wood ant mounds that lay along some of Germany’s biggest and most active earthquake fault lines, between 2009 and 2012. They monitored the insects’ movements with video cameras, entered the movements into a special software, and kept track of any deviation from the ants’ normal behavior patterns. The ants typically scooted around actively all day and went back to their mounds to rest at night. Yet, right before an earthquake they did not enter their mounds but loitered outside throughout the night. Once the earthquake was over, the ants would relax and go back to their regular routine. Even more interesting was that they did not change their behavior for tiny tremors below 2.0.

To Berberich, red wood ants (Formica pratensis and F. polyctena) can detect shifts in gas emissions with the chemoreceptors in their antennae and shifts in the Earth’s magnetic field with the magnetoreceptors in some of their sensory hairs. It is also possible that ants possess sensory organs that can respond to short-lived thermal anomalies or radioactivity.

Haicheng earthquake

Animal responses to earthquakes has been a topic of interest in China. It has led to survey and research studies. A network of experimental stations has been set up in areas with high seismic activity in order to evaluate extraordinary phenomena and other abnormal behaviors. The majority of the Chinese population lives in agricultural areas, so their proximity to animals makes them close observers. They have reported a great number of abnormal incidences preceding earthquakes, especially in the last 24 hours before a quake. It was found that the irregular behaviors of rats, fish, and snakes started three days before big earthquakes and continued until a few hours or even minutes beforehand.

Snakes came out of hibernation for two months in December 1974 and January 1975. It was as if they were committing suicide. Rats emerged from their dens and started to loiter in groups. These were both unexpected behaviors. The experts who evaluated the situation stated that a big earthquake was imminent.

There was first a series of small tremors. Snakes continued emerging from under the snow; bigger creatures such as cattle, horses, pigs, and dogs displayed restlessness. Thousands of such abnormal animal behavior were reported in the following month. Finally, on February 4, 1975, an earthquake of magnitude 7.3 struck the Haicheng County of Liaoning Province in northeast China. Far fewer people perished because they were warned of the quake thanks to the extensive observations of animals. Officials ordered the evacuation of one million residents of Haicheng a day before the earthquake, so there were only about 2,000 casualties. If the county had not been evacuated, fatalities and injuries would have been expected to exceed 150,000. The Haicheng earthquake is believed to be the only big earthquake that has ever been successfully predicted.

Geophysicist Friedmann Freund from NASA states that rocks under extreme tectonic stresses release electrically charged particles into the atmosphere before an earthquake. The particles react with air or water when they reach the Earth’s surface; they cause the formation of new molecules, like hydrogen peroxide, when they react with water. This chemical chain of events is believed to affect the organic material dissolved in the pond water, turning it into toxic substances for many aquatic animals.

Although there are supporting observations about the abnormal behavior of eels and toads, the findings are inconclusive. Still, there are considerable records of abnormal toad and snake behavior before earthquakes.

Snakes can perceive tremors and infrared radiation, which might help them detect possible weak shock waves or shifts in electromagnetic fields in a region before a powerful earthquake. Because rocks under stress emit infrared radiation – the anomalies of which were recorded by the NASA Terra satellite before a magnitude 7.9 earthquake that hit Bhuj, India, on January 21, 2001 – it is believed that snakes – nighttime hunters that possess a thermal camera for scanning the body temperature of their prey – can detect the infrared radiation that builds up before an earthquake. This infrared thermal “camera” is located inside a cavity between a snake’s nose and eyes.

It was once believed that snakes were unable to hear because they did not respond to loud noises. Snakes do not have external ears, and there is only one bone in their middle ear (columella aurii). However, they should be able to sense incoming vibrations, as they have inner ears. Indeed, a study at Princeton showed that snakes have a very keen sense of hearing. Voltmeter measurements of neural activity indicated that the vibrations from the air reached the inner ear through the jaw bone and had an effect on the brain. It seemed that the sense of hearing in snakes was tuned to the sounds and vibrations made by larger animals.

Studies have shown that snakes can detect sound by using sound pressure and sound-based mechanical vibrations. Experiments that measured the electrical responses of snakes’ head neurons and brain stems found that snakes can hear sounds of very high frequency. Snakes were found to hear sounds 10,000 times lower than is possible for human ears to hear. But how were the sounds transmitted to the inner ear of the snake, which was sensitive to vibrations? As low frequency sounds can be carried through solid substances, the research team wondered whether sound vibrations were transmitted from the ground to the snake’s body.

Subsequent research showed that skull vibrations had the same intensity as the minimum mechanical vibrations snakes could perceive. They directly responded to the vibrations that came from the air to the skeleton, rather than to sound pressure. A snake cannot possibly hear sounds from the air, but they can perceive the sound in a way that is unfamiliar to us. Snakes do not just hear what we perceive to be a sound: their entire body acts like a single organ designed for receiving vibrations, and their brains can perceive these vibrations as if they were sounds. It’s likely that the ribs and spines, covered with keratin scales, play a role in this transmission.

As research develops, we will be able to better understand what other creatures are equipped with troves of wisdom. It could open new windows into our world, allowing us to build safer cities and to appreciate the incredible intelligence of animals we consider to be “simple.”

The theory of plate tectonics explains what happens at plate boundaries. According to this theory, there are three primary plate boundary conditions; divergent, convergent, and transform boundaries. Divergent plate boundaries are characterized by ocean ridges and sea floor spreading; volcanoes are the most obvious setting. Here, a new crust is generated because the plates pull away from each other. Convergent plate boundaries are characterized by trenches and island arcs. In this setting, the crust is consumed in the Earth’s interior as one of the plates dives under another. In the case of transform plate boundaries, the crust is neither produced nor destroyed, as plates horizontally slide past each other. Significant earthquakes can occur under all of these boundary conditions.

We typically associate Japan with earthquakes because we know that it is a very earthquake prone island. The state of Alaska in the United States is also earthquake prone. The total number of earthquakes in Alaska per year is greater than the total number of earthquakes in the rest of the United States. The examples of Japan and Alaska reveal that more earthquakes occur at locations close to the plate boundaries. On a global scale, Japan, the Philippines, Indonesia, Chile, and western United States, are located along the so-called “Pacific Ring of Fire,” where about 90% of the world’s earthquakes and 80% of the world’s largest earthquakes occur.

The magnitude of an earthquake is a representation of the total amount of energy released by the event. Typically, it is measured using the recorded ground oscillations from a seismogram. However, the interpretation of the magnitude is not straightforward because the magnitude scale is logarithmic. For instance, a magnitude 7.0 earthquake produces approximately 10 times more ground motion and releases about 32 times more energy compared to a magnitude 6.0 earthquake (2).

According to the statistics published by the US Geological Survey, every year on average 134 earthquakes with magnitudes 6.0 to 6.9 occur worldwide, 17 earthquakes with magnitudes 7.0 to 7.9, and at least one large earthquake with a magnitude greater than 8 (Figure 3). Further, the number of earthquakes of magnitude 7.0 or greater has remained fairly constant but the number of moderate earthquakes (i.e., 6.0 or less) appears to be increasing. According to experts at the US Geological Survey, a partial explanation may lie in the fact that there is a tremendous increase in the number of seismograph stations in the world over the last twenty year. Thus, the actual number of earthquakes has not increased, but our ability to detect them. In scientific terms, this is referred to as reporting bias (3). When it comes to myths about earthquake activity related to weather and time, scientists rejects any connection. Earthquakes occur whether it is warm or windy, early in the morning or late at night.

In the United States, earthquakes are one of the most significant natural hazard for around 75 million Americans living in 39 states, including the state of California where the majority of the state’s population lives within 32 km of active faults. Historically, the region has been very active (Figure 4). To help predict earthquakes in California, a multidisciplinary group of scientists and engineers from various disciplines established a team entitled Working Group on California Earthquake Probabilities (WGCEP). The team had a very ambitious objective to develop a comprehensive earthquake rupture forecast model for the state of California using the best available science. The details of the sophisticated model are beyond the scope of this essay, but the recently released report (USGS Open File Report 2007-1437) is available for public access (5). In her essay entitled, “The big one is evitable. Catastrophe is not,” Cathleen Decker, an editor of the Los Angeles Times, refers to the future predictions presented in the report as a “Chilling look into the future” (7). Based on historical evidence and scientific data, it is almost certain (with a 99% chance) that there will be at least one earthquake with magnitude 6.7 or greater in the state of California within the next thirty years. The likelihood of a more significant earthquake (magnitude 7.5 or greater) within the next thirty years in California is 46%. In the Greater Bay Area specifically (area includes large cities such as San Francisco, San Jose, Oakland), the probability of at least one earthquake with magnitude 6.7 or greater within the next thirty years is about 67% (6).

The current state of science considerably reduces the risk of death and damage by making resources available to individuals, teachers, policy makers, and engineers, but unfortunately, science at this time can neither prevent nor predict the exact time when an earthquake will occur. Casualties, financial losses, and mental trauma are sometimes inevitable for earthquake victims. Social and emotional suffering are often not limited to actual victims, but to everyone who has access to the news. Unlike financial and material losses, the psychological consequences of an earthquake exposure are long lasting. To address these consequences, earthquake preparedness should include mental and social aspects of the disaster as well.

Reference

• This dynamic Earth The Story of Plate Tectonics by W. Jasquelyne Kious and Robert I. Tilling (Online edition) U.S. Department of the Interior, U.S. Geological Survey http://pubs.usgs.gov/publications/text/Vigil.html
• USGS Earthquake Hazard Program – Earthquake Facts and Statistics http://earthquake.usgs.gov/earthquakes/eqarchives/year/eqstats.php
• USGS Earthquake Hazard Program – Are Earthquakes Really on the Increase? http://earthquake.usgs.gov/learn/topics/increase_in_earthquakes.php
• California Geological Survey – Probabilistic Seismic Hazards Assessment – Historic Earthquakes http://www.conservation.ca.gov/cgs/rghm/psha/Pages/historic.aspx
• The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2) By 2007 Working Group on California Earthquake Probabilities, 2008 http://pubs.usgs.gov/of/2007/1437/
• USGS Earthquake Hazard Program – 2008 Bay Area Earthquake Probabilities http://earthquake.usgs.gov/regional/nca/ucerf/
• Los Angeles Times (January 17, 2010) http://www.latimes.com/news/local/la-me-week17-2010jan17,0,4714976.story

As to the former, the main causes of such disasters, where people are capable of significantly of influencing events are carelessness, inaptitude and inertia. We are often able to cope with and even learn from them. Learning lessons from these bitter experiences leads to improvements in safety conditions. Public places are built to be safer and redesigned to minimize the element of human error and to reduce the risk of accident. However, there is little man can do to arrest or mitigate the great eruptions of the earth.

Nowhere to run

The movement of the earth now affects more people than ever before, according to a recent report from the UN (Kerpelman, 1994). The number of people killed, injured or displaced by disasters has increased by 6 percent a year over the 30 years covered by the report. Charles Kerpelman, its author, says floods killed more people than any other type of disaster. In terms of numbers of people killed and injured, Southern Asia and Southern Africa have been the worst. However, ‘there is no area in the world that is really safe from disasters’.

Almost every part of the world is susceptible to at least one kind of disaster that has the potential for causing a large number of deaths and significant damage. In the past 100 years, 1 million people have died in earth-quakes, another million in hurricanes, typhoons and tropical cyclones, and as many as 9 million in floods-these figures do not include the millions of deaths from diseases and famine directly caused by these catastrophes (Robinson, 1993). We can learn from examining the several types of disasters and their effects.

The Atlantic is prone to storms, although the most lethal known storm occurred in the Bay of Bengal in November 1970, when winds of more than 160 kilometres per hour led to the death of an estimated half a million people. Over 45,000 people have been killed by hurricanes and intense tropical storms, in the region this century. The Pacific is not exempt. Hurricane Flora killed 5000 in 1963 on Haiti (Knapp, 1990).

Hurricanes are made of strong winds spiraling around the area of calm which is a few kms across. The largest hurricanes spread over hundreds of kilometres and last for many days. When Hurricane Frederic rushed into the Caribbean Sea in September it reached a speed of 230 kilometres per hour. Within a few hours, $2 billion of damage had been caused, explaining why hurricanes are called the insurer’s nightmare in America. They caused a total loss of $44.2 billion from 1987 to 1993 (Legget, 1993).

Volcanoes occur when the earth’s surface is breached and magma flows forth as lava exploding into the air as tuff. All volcanic eruptions are driven by rapidly expanding gases within the magma. The two factors that determine the violence of an eruption are the amount of dissolved gases and how easily they can escape (Beazley, 1992). In the past few decades we have seen the worst volcanic disasters since the start of the century with 25,000 people killed as a result of just three eruptions, El Chichn in Mexico (1982), Nevada del Ruiz in Columbia (1985) and Mount Pinatubo in the Philippines (1991).

Another class of disaster includes earthquakes. There are 150,000 noticeable earthquakes every year, and over a million can be measured using sensitive apparatus. Nowhere is totally free of earthquakes although the must serious ones are concentrated at the well known ‘faults’. The earth’s crust is not stable, several kinds of cracks and faults lead to earthquakes. In Tokyo 140,000 people-two-thirds of the city- were killed in 1923. More recently, 10,000 people were killed in Mexico City in 1985 and on 30 September 1993, Killari, a village in India, was reduced to rubble within seconds leaving 10,000 people dead. Of course, earthquakes themselves do not usually kill, the deaths are caused by the collapse of buildings, roads and other human artefacts. Considerable destruction is also caused by the aftereffects like fire, flood, landslide and tsunamis-tidal waves. As it is widely known, earthquakes alone are sufficient to destroy the prosperity of any country.

It is obvious that man cannot resist the giant force of the earth’s shock, however, we can hope to reduce the damages by predicting these events and being prepared. Unfortunately, scientists have not reached a reliable way of prediction.

Forecasting or monitoring?

Having suffered many horrifying cataclysms, man has been trying to develop technologies to predict when and where the next disaster emerge. Today, the technical description and analysis of disasters is far more detailed than the past, but we cannot say that man has achieved any reliable forecasting method. Scientists monitor the catastrophes, that is, they record the earth’s activity, they do not predict.

This century has brought scientists a better understanding of some aspects of hurricanes. Many of the major questions remain largely unanswered. We still have relatively little idea, for instance, why some storms turn into hurricanes and others do not; why some hurricanes make landfall and others remain at sea; what causes a hurricane to wobble or even to reverse. Until the arrival of satellites, hurricanes were awkward phenomena to study, impossible to encompass in their entirety. There are still many things to learn, as noted in Science in 1990 that after 30 years of advances in weather satellites, computer forecasting models, and basic research, forecasters have reduced error in predicting the paths of hurricanes by just 14 percent.

Despite the astonishing technology of the late twentieth century, volcanic eruption prediction remains a humbling science, The history of a volcano, both its geology and its eruptions, if known well enough, is often a good guide to its future behaviour, however, monitoring restless magma is one thing, forecasting when it will erupt is another The chairman of the Coordinating Committee for Prediction of Volcanic Eruptions wrote in Nature that ‘the prediction of eruptions is extremely difficult….the prediction of the date and time of initial outburst is still like a kind of betting’ (Robinson, 1993). Recently, radar systems have been used to study erupting volcanoes, however, Rick Hobblit, a volcanologist admits that the single most important piece of information you can have is whether an explosive eruption is in progress’ (Pendick, 1993).

The introduction of a special issue of The Bulletin of the Seismological Society of America stated that ‘earthquakes do not have to occur where and when we want them or forecast them to occur and our understanding of how and why earthquakes occur and recur, even along the best studied active crustal fault in the world, is rudimentary and incomplete’. Brian Brady, a geologist studying quake-like rock bursts in mines, had made a notorious prediction that a giant earthquake would strike Peru in June 1981. The people of Peru, 66,000 of whom had died in an earthquake as recently as 1970, became jittery and restless as June 1981 approached. The result? Nothing happened. Later Brady wrote, defending himself that ‘our expanding knowledge of the earth derived from the extraordinary sophistication of new instrumentation, has ironically served to magnify our lack of understanding’ (Robinson, 1993).

Not only to destroy

So far, we have attempted to show the damage caused by disasters and the level of our understanding of them. Bearing in mind that everything in the universe exists or happens for a reason, we may ask ourselves what is behind these catastrophes which cause such great loss to destruction. As Charles Darwin said reporting the ruin of Concepcion in Chile, by an earthquake, ‘it is a bitter thing to see works, which have cost man so much time and labour, overthrown in one minute’. But unlike Darwin, we believe every event in the universe is planned. Elsewhere, our scholars have explained this more fully. Here it is sufficient to say that like everything in the universe, disastrous activities of the earth, too, have some benefits to earth and its inhabitants.

Storms and hurricanes help disturb the whole depths of the sea so that plankton-tiny creatures on which most fish swimming near the surface feed-get their food as chemicals from the sea bed. They carry heat from the tropics to the poles helping to even out the world temperatures. If this did not happen the tropics would get hotter and hotter. The poles would ice over without the heat from the tropics. Storms and hurricanes simply do the vital job of carrying surplus energy quickly across the earth. Severe storms such as hurricanes help drought-stricken lands recover. When dry air sits over continents like Asia, a great concentration of energy is needed to make big clouds that will bring rain. This is usually provided by hurricanes (Knapp, 1990).

It is widely known that volcanic eruptions have an overall cooling effect on the earth. Volcanoes cool the globe by injecting large quantities of material into the stratosphere, especially droplets of sulphuric acid. Once in the stratosphere, this material absorbs heat from the sun, preventing it from reaching the ground. This influence can last for several years.

Already, the Pinatubo eruption has cooled the earth’s surface by an average of 0.5 °C. One other benefit of volcanic eruptions is their 20,000 atm- pressure from magma to surface which helps the earth harden and provides protection from earthquakes. The idea that the volcanoes diminish the ozone layer is denied by recent research which argues that ‘the chlorine emitted during volcanic eruptions is not responsible for the damage to ozone layer. Two researchers in the University of California have shown that although large amounts of hydrogen chloride are released during some volcanic eruptions, the compound is efficiently washed out in the rain that always accompanies such eruptions’ (Science, vol.260, p.1O82).

Conclusion

We have attempted to show the effect of disasters in terms of loss of life and money and how far we are from understanding the earth and its activities. Even the dazzling technological advances of the twentieth century could not help us overcome the violence of the earth-shaking events, apart from showing us our lack of understanding. Scientists need to carry on experimenting and studying the mysteries of the world so that man can cope with nature. We must always bear in mind that all those horrifying activities of the earth are not purposeless and free from reason but help maintain the earth’s vitality. They perform tasks that cannot be carried out in more gentle conditions.