ADVERTISEMENT
  About the SA Blog Network













History of Geology

History of Geology


What rocks tell and how we came to understand it
History of Geology Home

Can Animals Sense Earthquakes?

The views expressed are those of the author and are not necessarily those of Scientific American.


Email   PrintPrint



Highly unlikely, but not outside the realm of extreme possibilities.
Mulder, F.W. in the “The Jersey Devil” (1993)

The earliest documented case of unusual animal behaviour prior to an earthquake is recorded by the Roman historian Aelian in 373 B.C.; five days before an earthquake destroyed the city of Helike (once located at the coast of the Corinthian Gulf) various animals, like rats, weasels, snakes, centipedes and bugs supposedly emerged from the underground and fled from the city. In the following centuries many other cultures associated earthquakes with animals.

According to Japanese myth the cause of earthquakes is the giant catfish Namazu who lives buried in the underground. By moving his tail he can shake the entire earth and unfortunately he loves to cause trouble and havoc. However in early traditions the catfish also acts as premonition of danger, warning people from an imminent catastrophe or by swallowing dangerous water-dragons prevents further catastrophes.
Before the earthquakes of Edo (modern Tokyo) in 1855 and later in 1923 apparently catfishes acted weird, displaying increased activity and swimming to the surface of ponds and rivers.

Similar to Japan, also in China animals were regarded to possess some insights to the natural elements and disasters. Chinese authorities considered 58 species of animals to be useful for earthquake prediction, especially snakes, rodents and bats, and distributed booklets with depictions and descriptions of unusual animal behaviour worth to be reported.
In February 1975 hibernating snakes abandoned their hideouts in the north-eastern city of Haicheng. The city was evacuated and February 4, the region was hit by a 7.3 magnitude earthquake. More than 1.000 people were killed, but considering the densely populated area the prediction an evacuation was considered a great success.

Fig.1. & 2. Snakes and fishes are common animals in reports dealing with unusual animal behaviour prior to an earthquake. Both organisms possess particular sense organs: snakes can perceive vibrations and infrared radiation, fishes perceive electric fields. Maybe these senses help them to detect environmental changes, like weak foreshocks or variations in the local electromagnetic field, before a strong earthquake.

However just one year later on July 27, 1976 an unforeseen earthquake hit the city of Tangshan, killing 655.000 people. A later inquiry established that there were some reports on unusual animal behaviour; however the reports were ignored due the political tumults during the culture revolution. Before the Wenchuan earthquake (7.8 magnitude, 12.05.2008) apparently a migration of frogs was recorded in the city of Mianyang, located in the later area of devastation.

Also in the western civilizations stories about animals acting weird hours or days before an earthquake are repeatedly retold. One day before an earthquake devastated the Italian province of Friaul (6.5 magnitude, May 6, 1976) mice were seen running in open spaces and farm animals showed signs of restlessness.
After the earthquake and devastating tsunami of Christmas 2004 almost no carcasses of wild animals were found, apparently the animals fled into the interior of the islands before the arrival of the waves.
Also the earthquake in Virginia (5.8 magnitude, 23.08.2011) was sensed by the animals at the Smithsonian’s National Zoological Park in Washington. Most animals reacted to the shakes by a general restlessness, but apparently apes climbed onto trees some minutes to seconds before the shakes were noted by the zoo staff.

The problem with this long (and far from exhaustive) list is that almost all these cases are anecdotes, reported after the earthquake and based on the subjective impression of what was considered at the time an unusual behaviour for an animal. Many anecdotes are also retold in the literature or in the web out of context. The evacuation of Haicheng was based mainly on a sequence of foreshocks that occurred months and days before the earthquake and the authorities had suspected for years that a larger earthquake could occur in a region with past strong earthquakes. The animals didn’t behaviour strange without lacking an apparent reason (and “foresee” an unexpected earthquake), but reacted to the continued and almost daily trembles and foreshocks.
The plural of anecdote is not data“, however anecdotes can be used to formulate a hypothesis: are there environmental changes caused by tectonic tensions that could be detected by an organism?

It is almost sure that there exists no specific animal sense to detect an earthquake; Bora Zivkovic discusses the particular, however not paranormal, senses of animals on his “Observations. It seems however reasonable to assume that animals show reactions to variations of their environment caused by an earthquake or the tectonic processes that can cause an earthquake.
There are two kinds of unusual animal behaviour reported in the literature: Short time reactions, minutes or seconds before the earthquake, and long term reactions, days to weeks before the event.

Various physical phenomena were proposed to explain why animals react to incoming seismic waves some moments before humans do.
- Many animals can perceive infrasound that propagates much faster in the air (330m/s) than a Tsunami (200m/s). This could explain why animals apparently fled from the approaching Tsunami in 2004. Low-frequency sound waves and vibrations from weak foreshocks can be felt by animals like elephants or birds, fracturing rocks generate high frequency sounds that could be heard by rodents.
- An earthquake is composed of various types of seismic waves. P(rimary)-waves travel 1,7x faster than the more destructive S(econdary)-waves. Similar to infrasound waves and tsunami waves, this relative difference in velocity could explain the apparent reactions of animals some moments before the stronger S-waves arrive.

Explaining long term reactions is much more difficult.
-Fishes, birds and other animals can detect changes in the electric or magnetic field and accumulating tensions building up in the crust could also affect the local fields, however in case of magnetic variations this effect is very weak.
- Snakes and some insects can detect thermal variations based on their infrared vision. The physicist Friedemann T. Freund demonstrated in 1993 that rocks under tension emit infrared radiation and infrared anomalies were also recorded by the NASA Terra satellite before the magnitude 7.9 Bhuj earthquake (India) January 21, 2001. Maybe snakes can “see” the accumulating stress applied to rocks by telluric movements.
- Based on these observations in the last years also an “Electrical Field Hypothesis” was proposed. In a first version of this idea the accumulating tectonic tensions cause a current of electric charges in the rocks due the piezoelectric effects of minerals like Quartz. However as noted by Andrew Alden on a discussion on “Earthquake Lights (caused supposedly by such electric fields) the generated voltage is negligible.
The “p-Hole Theory“, also formulated by Freund, assumes that negative charged oxygen ions are removed from the respective position in the structure of a mineral, a positive charged “hole” remains in the crystal. These holes migrate to the surface of the mineral grain and can ionize other atoms, which are released into the atmosphere or the groundwater. GRANT et al. 2011 use this mechanism to explain the supposed disappearance of mating toads some days before the earthquake in L’Aquila on April 6, 2009 (the news based on GRANT et al 2010 about “earthquake predicting frogs” became very popular in the media). The paper proposes that charged ions modified the water chemistry of the aquifer and springs of the area and that the toads reacted to these variations in their usual environment. After the earthquake and release of the tectonic tensions also the ionization effect of the rocks disappeared, bringing the water chemistry back to normal levels.

Fig.3. The observations of GRANT et al. in spring 2009 (click on figure to enlarge) at the reservoir of San Ruffino (some km distant from the later epicentre of the earthquake of L’Aquila April 6, 2009). The research focused on the mating behaviour of toads (Bufo bufo). Some days before and after the earthquake the number of observed male toads decreased apparently without a specific reason.
The upper line shows disturbances in radio signals, caused by interferences in the ionosphere. According to the proposed scenario the accumulation of positive charges on the ground due tectonic tensions influenced the ionosphere and therefore can be used as a proxy of the release of ions into the environment of the toads. In the end the toads reacted to chemical changes caused by these ions.

It is important to note that these are all plausible, but hypothetical mechanisms. It is almost impossible to test the behaviour of an organism for a not foreseeable event like an earthquake. Animals in the wild or the zoo could react to other environmental factors, when coincidentally an earthquake occurs. The rare observations of animals in a laboratory during an earthquake show contradictory results, sometimes behaviour interpreted as unusual was observed, in other cases nothing happened or the supposed reactions were exact the opposite than recorded by other researchers.

We can assume that some animals are influenced by environmental changes that can occur before an earthquake; however our understanding of such possible precursor effects and how organisms react to them is still limited. As long as this gap exists the unusual behavior of animals alone can not be used to evaluate an increased earthquake risk.

Bibliography:

BHARGAVA, N.; KATIYAR, V.K.; SHARMA, M.L. & PRADHAN, P. (2009): Earthquake Prediction through Animal Behavior: A Review. Indian Journal of Biomechanics: Special Issue NCBM 7-8: 159-165
GRANT, R.A. & HALLIDAY, T. (2010): Predicting the unpredictable; evidence of pre-seismic anticipatory behaviour in the common toad. Journal of Zoology 281(4): 1-9
GRANT, R.A.; HALLIDAY, T; BALDERER, W.P.; LEUENBERGER, F.; NEWCOMER, M.; CYR, G. & FREUND, F.T. (2011): Ground Water Chemistry Changes before Major Earthquakes and Possible Effects on Animals. Environmental Research and Public Health 8: 1936-1959
IKEYA, M. (2004): Earthquakes and Animals: From Folk Legends to Science. World Scientific, London: 295
KIRSCHVINK, J.L. (2000): Earthquake Prediction by Animals: Evolution and Sensory Perception. Bull. Seism. Soc. Am. 90(2): 312-323
SCHNYTZER, Y. (2011): Animal Modeling of Earthquakes and Prediction Market. Working paper
TONG, K. (1988): Abnormal Animal Behavior and the Prediction of Earthquakes. Master Thesis Dep. Earth Sciences Northeastern Illinois University.

David Bressan About the Author: Freelance geologist dealing with quaternary outcrops interested in the history and the development of geological concepts through time. Follow on Twitter @David_Bressan.

The views expressed are those of the author and are not necessarily those of Scientific American.



Previous: Mammoth Mummies Mysteries More
History of Geology
Next: Geology of the Mountains of Madness




Rights & Permissions

Comments 7 Comments

Add Comment
  1. 1. poihths 7:21 am 12/14/2011

    This article, and this subject, are both excellent and instructive examples examples of how difficult it can be to move from “we suspect” to “we know.” Human beings are hardwired, or so the neuroscientists seem to be telling us, to make that jump prematurely. Hence the general acceptance of the idea that animals predict earthquakes.

    Link to this
  2. 2. GOSKAM 9:34 am 12/15/2011

    In 2003 my wife and I spent 10 days in Tokyo, Japan.We lived in the Fairmont hotel adjacent to the gardens of the Imperial Palace. Every night there was a strong chorus of innumerable numbers of crickets in those gardens. One night we arrived at 11 p.m. in the hotel. Both my wife and I thought it strange that not a sound of the crickets was to be heard. Two hours later we awoke shaking in our bed during maybe 20 seconds. The following morning we were told that it was just a 3.0 magnitude earthquake. Nobody seemed to be much concerned, because such small earthquakes were considered as quite common and without danger. The following nights the crickets were back in full force and we felt that we could sleep without any disturbance. Of course there is no science in this, but we still think that the crickets “sensed” the arrival of that small earthquake.

    Link to this
  3. 3. T.Roccetta 11:20 pm 01/4/2012

    Nice article David – good job.

    First comment is to Goskam above:

    “..shaking in our bed during maybe 20 seconds… a 3.0 magnitude earthquake..”

    One of those facts is wrong, it’s doubtful (but not impossible) that you would even feel a 3.0, but basically impossible that it went on for 20 seconds. There is a relation with magnitude and length of time. Maybe you heard wrong, and it was a 5.3? That’s still fairly small for active areas, and people would take it in stride. Even that magnitude would not shake for 20 seconds though, but much closer.

    One question for you, David: when you say “..almost all these cases are anecdotes, reported after the earthquake”, what are you basing that on?

    You can imagine the kind of official reporting system that would have to be in place beforehand in order to establish a time of report. A ‘generic’ (ie not a seismic precursor expert) public official would not know what to do, or have the existing guidelines to use. They would sit on reports, not wanting to bother a superior. After the quake happened, the opposite would occur; not wanting to look bad, combined with a large increase in the number of people reporting after the fact, the data would tend to get lumped together.

    I have a bit more to say in an ongoing thread about earthquake precursors, where this article is now linked:

    http://saposjoint.net/Forum/viewtopic.php?p=36070#p36070

    :)

    Link to this
  4. 4. David_Bressan 9:28 am 01/9/2012

    Interesting discussion indeed – would be very informative to get first-hand reports of the authorities or geologists of the Haicheng-earthquake, I’m aware only of transcripts of American geologists and a old propaganda movie (and there is the danger that facts were twisted to prove the point). If there are further developments we could post it here (considerig aslo the limits of a single post, the are entire books dealing with this subject).

    As for modern research: Many investigations (like this http://animalsandearthquakes.com/ ) I’m aware called for testimonies after the earthquake with the simple request to report “unusual behaviour” – the problem is that these studies don’t define the data they will work on: what is unusual behaviour? Is unusual behaviour defined for s species or a single individual? Is this unusual behaviour only explainable with an earthquake? If so, which effect of an earthquake is causing this behaviour (shacking, magnetisms, sound waves, etc.) Is this observation repeatable?

    That’s my main problem with anecdotes: Owner of pets will testimony that animals have sometimes their moods or change they pattern without apparent reason: cats are creatures of habit. ,and my has they usual place to sleep, but from time to time suddenly she changes place, in rare cases even places never used before ; if now an earthquake happens there is the possibility that I would see an erroneous correlation in this “fact”.

    It’s a bit a problem like the hen and the egg, to test unusual behaviour we have first to define what unusual behaviour is… to know what unusual behaviour is we have to observe and test it

    This of course brings us the second questions – how to design an experiment to test this hypothesis.

    There are sporadic research focusing on specific animals, like snakes in China or fish-species in Japan, continuously monitored and hold in a laboratory. The results until now however – at best – are controversial – there are probably still too many variables to consider in a living organism. Maybe future or smarter scientists will have a good idea to design such a specific experiment.

    It is important to note: animals must react to physical changes of the environment, it doesn’t help to invoke magic or supernatural powers like some researchers or the public do (per definition such things are untestable). With this premise also the bad “western” science is willing to investigate these claims (as proves the rich literature dealing with the topic).

    I think the potential of such research is in another direction: Instead of using animals as living seismometer, if we understand what phenomena the animals react, maybe we could try to develop a specific monitoring-system, techno-equipment would have the great advantage to exclude many variables that affect organisms.

    Link to this
  5. 5. blueLemming 10:22 pm 04/4/2012

    Are any of the modern medical imaging techniques reasonable and safe for use in monitoring animals for a period of time, in an area with a high frequency of earthquakes? If practical, this might give an idea what sort of nervous system activity was associated with an animal sensing a coming earthquake, which in turn could help pin down what it is (if anything) the animals are sensing.

    Link to this
  6. 6. David_Bressan 12:32 pm 04/9/2012

    As I know no medical monitoring is done (for example monitoring cerebral activity with EEG or similar)yet, as the effort of it would be to complicated and also probably influence the behaviour of animals to much.

    What is done is surveillance of activity of animals, like in the city of Nanning snake farms & the behaviour of animals are monitored since 2005 with webcams from the local university.
    Also the influence of ionized air (as some explain the behaviour of animals due the ionizing effects of tectonic stress on rocks & air) is observed on rats, in two interconnected chambers the animals seems to prefer the chamber that is not exposed to an ion source.

    Link to this
  7. 7. alanwatson12 4:51 pm 10/24/2013

    Going back a few years, the idea that animals would respond to seismic effects prior to earthquakes intrigued me. I spent a lot of time thinking about how this could be proven statistically. This idea just ‘felt correct’, ‘felt real’ and I wanted to prove the point.

    In 1990 I noticed that a significant earthquake in Shropshire, England occurred the day after the onset of violence in the Strangeways Prison Riots and two days after the Poll Tax Riots in Trafalgar Square, London.

    I began to wonder if it was possible that humans could respond to seismic effects prior to earthquakes. Is it possible that a human response to seismic effects may take the form of rioting and disorder – extreme behaviour which it is possible to assess statistically.

    I therefore started to compile a list of riots in England and Wales and compared that with a list of earthquakes of Magnitude 2.5ML and greater obtained with the kind permission of British Geological Survey.

    The results were absolutely extraordinary. There is clear and compelling statistical significance that riots are far more likely to occur in the 14 days before earthquakes than would be expected by chance.

    If you want to see this statistical proof it is presented in my e-book ‘Gravity and Mind – Human Response to Tectonic Stress’ available on all the main e-book sales platforms.

    As far as I am concerned, a Human Response to Tectonic Stress is a reality of our existence on this dynamic earth and on the basis of my research I would be very surprised if some sections of the animal kingdom did not exhibit some kind of behavioural response.

    Alan Watson

    Link to this

Add a Comment
You must sign in or register as a ScientificAmerican.com member to submit a comment.

More from Scientific American

Scientific American Special Universe

Get the latest Special Collector's edition

Secrets of the Universe: Past, Present, Future

Order Now >

X

Email this Article

X