Why Earthquake Prediction Is Difficult?

Introduction3

Discussion3

Predicting Earthquakes4

Prediction Techniques5

Conclusion8

References9



Why Earthquake Prediction Is Difficult?

Introduction

Science in recent years has made much advancement, but despite all the successes, predicting earthquakes is one of the most difficult tasks for scientists. All the predictions of earthquakes are based on statistics and may not indicate the exact date of the disaster. In order to make the prediction more accurate, it is necessary to take into account all environmental signals. Earthquakes, in fact, occur in a random and in some cases it is possible to trace the seismicity to the concept of deterministic chaos. The earthquake has random pattern, but can be explained by a deterministic mechanism (Molchan & Romashkova, 2011).

Discussion

The main purpose of prevention of earthquake is to mitigate its hazards. In fact, it is evaluated as a function of hazard, vulnerability and exposure of seismic. It is expressed for the expected damage as a result of an earthquake, in terms of loss of human lives and economic costs due to damage to buildings and blocking of productive activities. Since it is not possible to change the seismic hazard of an area, the only way to reduce the seismic risk and to lessen the effects of an earthquake is to reduce the seismic vulnerability and exposure (Molchan & Romashkova, 2010).

An effective strategy for the mitigation of seismic risk requires an adequate description of expected earthquakes, and effects related to the propagation of seismic waves. It is necessary, to answer the following questions:

Where, when and how strong an earthquake can hit the region in question?

What are the consequences to be expected if it occurs?

The answer to the first question is about the earthquake prediction, while the second is the subject of studies of seismic risk. The complex character of the seismic phenomena does not seem to allow deterministic forecasts, consequently it is not possible to know in advance how (i.e. the place, the time and magnitude) with which the earthquake will occur with sufficient precision to put in place an evacuation plan. In addition, even statistical forecasts are reliable, as, by any seismogenic region of a size sufficiently small (a hundred kilometers); the number of strong earthquakes is too small to allow defining the probability of occurrence with the required accuracy (Molchan & Keilis-Borok, 2008).

Predicting Earthquakes

The prediction of earthquake is not easy. Earthquakes occurs most frequent and disastrous, that are of tectonic origin, and are always proceeded by local and temporary variations of the geomagnetic field. In fact, the approach of the total moment of rupture gives rise to seismic discharge, due to the strong state of pressure and stretching of the rock mass. It is determined in the focal zone of alteration of the electromagnetic state of the rocks, which results in the local variation Earth's magnetic field (Marzocchi & Zechar, 2011).

Prediction of earthquake is useful, because they originate at the approach of the moment of breakage of rock masses that generates the earthquake. An anticipation that can vary generally from one to ten ...