Comprehensive Earthquake Prediction Based on Earthquake Sounds, Abnormal Animal Behaviors and Pre-shock Ground Heat Effect
By YU Yuntao, Shijiazhuang University of Economics
The Wenchuan Earthquake in Sichuan had led to great loss of life and properties in the stricken areas. Earthquake prediction has once again roused great attention since the Tangshan earthquake. To do a good job in the forecasting surely becomes the wish out of all of us. This paper expresses my own thoughts of prediction based on earthquake sounds, abnormal animal behaviors as well as the combination of both, and I will be thrilled should it be some help with the actual prediction work.
I. A Dynamic Experiment
Many years ago, there was this dynamic experiment shown on TV: a cubic stone with gradually added pressures from up and down by the press. In the beginning, there is no deformation or sound. Yet when the pressure reaches a certain point, the stone suddenly cracks with a large sound and small pieces bursting to everywhere. The ultrasound during this period was not recorded as this was not the purpose for the experiment.
Now related information on the internet has shown that in the above experiment, the basic transformation course of the stone is:
A whole integration with mechanical intension not influenced by anything
Certain small crannies with inaudible ultrasound
With the accumulation of pressure, the small crannies become larger and larger, while the ultrasound weaker and weaker
At the point that the stone splits and cracks, there are the audible sound waves.
The micro crannies in the stone are called micro-fracture. The time from the appearance of micro-fractures to the cracking point of stone is called micro-fracture period.
If possible, there should be further trials and experiments concerning stone with different types and volumes, testing their ultrasonic frequency and intensity in the micro-fracture period, for the use of earthquake prediction research. Surely, recording work is important so as to note the changing frequency and intensity of the ultrasound.
II. Earthquake Sound
1. Earthquake sound is a seismic precursor
With the approaching of an earthquake, the pressure on the underground rocks is accumulating. We’ve known from the above that in the micro-fracture period, there is ultrasound, or namely high-frequency earthquake sound. At the arrival of earthquake, there would be rocks cracking, producing audible sound waves, or audible earthquake sound. Both high-frequency and audible earthquake sound falls into the domain of earthquake sound, which apparently is a seismic precursor.
Before earthquake takes place, underground rocks are entering the micro-fracture period with large pressures from around. The detailed characteristics of the high-frequency sound can be concluded from researches over the sound records of the previous earthquakes in related places.
2. Characteristics of high-frequency earthquake sound
According to their conditions and spreading channels, known high-frequency earthquake sounds boast the following characteristics:
(1) High-frequency earthquake sounds are ultrasounds in the micro-fracture period while underground rocks are enduring large pressures. As the underground rocks are mostly huge, the intensity of the ultrasounds produced should be, in my opinion, quite strong and its transmitting distance quite long.
(2) The frequency, tone and timber of the high-frequency earthquake sounds depend on the size and components of the rock. Its transmission, however, is seldom interfered.
(3) From the above dynamic experiment, when the frequency of high-frequency sound drops to that of the audible sound, earthquakes would be arriving in a minute or immediately. This is the characteristic possessed by brittle material, which is critical to determine the time of the earthquake.
(4) As high-frequency earthquakes sounds are produced by the micro-cracking of rocks, many animals would be upset and scared at hearing and thus behaving abnormally.
To sum up, high-frequency earthquake sounds are probably the most direct and essential earthquake precursor, with highest intensity, most extensive transmission and largest influence. Due to its relatively small disperse of frequency change, the prediction of earthquake occurrence and time is comparatively reliable.