Wednesday, 7 December 2011

Predicting earthquakes through remotely-sensed information: Possible?

Precicción de sismos a través de información remótamente percibida: Posible?

There is research which suggest that earthquakes could be predicted by non-traditional methods. For such purposes, the alternatives being explored range from, the monitoring of the behavior of some sensitive terrestrial and aquatic animal species, to the monitoring of regional changes in the electromagnetic spectrum through advanced remote sensing techniques. In the case of animal species, the approaches vary from the relatively simple, yet interesting, investigation of the higher sensitivity of domestic species to minor ground vibrations (e.g., browse for Prof. Mitsuaki Ota, Azabu University), to more advanced approaches that suggest that stressed rocks release electrical charges that alter the chemistry of water (e.g., Grant et al., 2011). The use of remote sensing techniques is related to the latter suggestion, based on the idea that the amount of energy released during tectonic displacements should alter the electromagnetic spectrum for some days before the occurrence of a major event (see the review by Alvan et al., 2011).

I first heard of those approaches back in 2007, when I was carrying my graduate work in Japan, at the exact time I was writing a report for my lecture in Environmental Remote Sensing. So, then I decided to do some research on whether the big earthquake felt there on August 16th 2005 (the Miyagi Oki earthquake, or Miyagi offshore earthquake) could be observed from satellite platforms or not. I used Aster thermal images, and the results are shown in the picture above. Let me help you to interpret the images. The header shows the date (August, 9, 10, 11th, 2005), days before the event of August 16th 2005, where I was interested. The red and green spots are clouds, so they should be discarded. The land is in blu-purple tones, and can be better observed on the upper part of the third image (the image on the right). What is interesting about the simple analysis I present is the harsh line on the sea, which vanishes for dates after August 11th. Have you found what I describe? Let me show you what I meant in the picture below:

 After having analyzed the images shown, I got shocked, because as I mentioned, the major disturbance on the Pacific Ocean that, occurred in from of Sendai, where the earthquake struck four days later. The particularity of such disturbance was that such have an unusual geometrical shape. Then I continued investigating whether or not  this phenomena was observed during other events, e.g., the Kobe earthquake 1995, and another event that struck Tokyo few months later. Unfortunately, the results would not find a disturbance similar to the one I found in front the coast of Sendai, perhaps because one of the events, Kobe´s epicenter occurred in the city and not in the sea; however, Tokyo´s event epicenter occurred in the sea, but no clue could be found. Then I went back to information on the fault that caused the event of 2005, to see if it was located on the disturbance I had found, and then, again nothing.

Conclusion. I could not determine the nature of such unusual geometric-shaped disturbance. This shows how complex earthquake prediction is. Sure, the ideas from past research suggest that they may be several hints, not yet well analyzed or understood; however, as I demonstrated, those seem to be not enough, and much research is still needed. In my next post I will investigate whether or not there is some disturbance in the sea before the great event of March 15 2011. If so, you may not see my results here before I publish them.


Alvan, H. et al., (2011) Overview of remote sensing techniques in earthquake prediction. J. of Engineering, Design and Technology, Vol. 9 Iss: 2, pp.164 - 177.

Grant et al., 2011. Ground Water Chemistry Changes before Major Earthquakes and Possible Effects on Animals. Int. J. Environ. Res. Public Health, 8, 1936-1956; doi:10.3390/ijerph8061936

Press releases:
Earthquake rocks northern Japan.BBCnews

How animals predict earthquakes? by Victoria Gill, BBC (tambien en español).

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