Earthquake,vibrations produced inside the earth. The vibrations can range from barely noticeable to catastrophically destructive. There are six kinds of shock waves generated in the process. Two are classified as body waves and the other four are surface waves.
The general classes of earthquakes are: tectonic,vulcanic and artificially. The tectonic is the most devastating but scientists find ways to predict them.
The tectonic earthquake is situated in zones where one plate slides past another,for example at the San Andreas fault in California.If one plate will slide below the other at a sharp angle the earthquakes in these areas are not so strong,but if two plates are sliding beside each other,one plate will often be forced under the other at a shallow angle so these eartquakes are more frequent and stronger.In these regions they can cause great loss of life by destroing structures, buildings, bridges and they can also devastating nature






Seismologists have devised two scales to desribe earthquakes quantitatively. One is the Richter scale-named after american seismologist CH.F.Richter, which measures the motion of the land from the epicenter to focus.The Richter scale is open-ended.The other scale was invited in 20th century by the italian seismogolist Giusseppe Mercalli.This scale measures the intensity of shaking from 1 to 12.
The strongest earthquakes were in 1906 in San Francisco 8.3-9.2 and in 1964 the Alaskan earthquake 8.4-9.2 richter´s scale, but the biggest one was in Tokyo
with the loss of 200 000 lives. It was past but now we can predict the earthquakes and it help´s people in stricken areas..


Drought, condition of abnormally dry weather within a geographic region where some rain might be expected. Drought is quite different from a dry climate,which
designates a region that is normally, or at least seasonally dry. Catastrophic droughts generally occur at latitudes 15-20.