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).
Image credit: NASA. The two main answers to âhow earthquakes happenâ is: as a result of tectonic plates colliding and volcanic eruption. The shock waves associated with nuclear weapons testing and other man-made explosions. To be considered an earthquake a shock wave has to be of natural origin.Earthquakes Caused By Tectonic Plates: The theory of plate tectonics explains how the crust of the Earth is made of several plates, large areas of crust which float on the Mantle.Since these plates are free to slowly move, they can either drift towards each other, away from each other or slide past each other.Many earthquakes happen in areas where plates collide or slide past each other. The Elastic Rebound Theory applies to these quakes.ince these plates are free to slowly move, they can either drift towards each other, away from each other or slide past each other. Many earthquakes happen in areas where plates collide or slide past each other. The Elastic Rebound Theory applies to these quakes.