Earthquakes are the result of rocks breaking under stress. The constant movement of the tectonic or lithospheric plates (the thin outer shell of the earth), creates stress which builds up beneath the Earth's surface. Sometimes rocks are abe to adjust to this stress by folding, but from time to time the stress is released by fracturing of the rocks. These fractures form geological faults and cause the sudden and sometimes disastrous vibrations we know as an earthquake. The vibrations of an earthquake, technically known as seismic waves, travel outwards in all directions from the fault, if the earthquake is large enough the seismic waves produced are recorded on measuring instruments known as seismographs around the globe.


There is an abundance of material available about earthquakes in both printed form and electronically via the world wide web. Where possible I have made links to useful URLs related to earthquakes throughout the site. The information contained within these pages of Earthquake basics must pay credit to the seismologist and author Bruce A Bolt and his three wonderful books;

Nuclear Explosions And Earthquakes The Parted Veil, WH Freeman and Company, Published 1976

Earthquakes, Revised And Updated, WH Freeman and Company, Published 1993

Earthquakes And Geological Study, Scientific American Library, 1993

These pages are intended for educational and research purposes only. I felt the need to translate various texts by Bruce A Bolt so as persons with little or no understanding of earthquakes could in a short period of time in reading the material contained within have a good base understanding. It is my belief that information should be made available but when information is used for financial gain through means of plagarism one should be wished upon that unfortunate misgivings lie before them. The old ethos "That information wants to be free" applies here!

DV Rogers, Nov, 2000