Feudalism was a combination of legal and military customs in medieval Europe that flourished between the 9th and 15th centuries. Broadly defined, it was a way of structuring society around relationships derived from the holding of land in exchange for service or labour. Although derived from the Latin word feodum or feudum, then in use, the term feudalism and the system it describes were not conceived of as a formal political system by the people living in the Middle Ages. In its classic definit
Causes of Earthquakes. Most earthquakes are causally related to compressional or tensional stresses built up at the margins of the huge moving lithospheric plates that make up the earth's surface (see lithosphere).
This causes earthquakes such as the Koyna earthquake in Maharashtra. The shock waves through rocks set up by the underground testing of Atom bombs or Hydrogen bombs may be severe to cause earthquake. Effects of Earthquake Destructive Effects: Earthquake causes dismantling of buildings, bridge and other structures at or near epicenter. Many men and animals are killed or buried under collapsed houses. Rails are folded, underground wires broken. Fire breaks out inevitably in large towns. Earthquakes originate sea waves called Tsunamis. Earthquakes result in the formation of cracks and fissures on the ground formation. The earthquakes cause landslides and disturb the isostatic equilibrium. Landslide due to earthquake may block valleys to form lakes. Constructive Effects: Sometimes the earthquakes cause formation of hot springs which are very useful to people.