Definitions of EM

1. Write a definition for the followin conceps and add an image to clarify your explanations.
-Ocean trenches
-Mid ocean ridge
-Fault
-San Andreas fault
-Formation of islands
-Formation of mountains

Ocean trenches:  Ocean trenches are deep depressions on the seafloor, they are the deepest part of the ocean. In every basin of the planet there are ocean trenches. They are a result of tectonic activity.

http://education.nationalgeographic.org/encyclopedia/ocean-trench/

Mid-Ocean ridge: A mid-ocean ridge is an underwater mountain, this is create when currents rise under the seafloor and create magma where tectonic plates meet.

https://www.sciencedaily.com/terms/mid-ocean_ridge.htm

Fault: Faults are features in the earth where rocks in both sides had slide away from each other . There are 3 types of faults, the strike-slip fault, the reverse dip-slip fault and the normal dip-slip fault.

http://www.windows2universe.org/earth/geology/fault.html

San Andreas Fault:  San Andreas Fault is the limit between the North American plate and Pacific plate. In 1906 there was an earthquake that left the San Andreas fault as a consequence. It does not go through cities but many communities are sitting ducks

http://geology.com/articles/san-andreas-fault.shtml

Formation of islands: Volcanic islands are formed by volcanic activity in the seafloor, 

often near the limit between tectonic plates.  Two plates pull apart and lava erupt, 

then layers of lava build up until they protrude up water. 

http://www.infoplease.com/dk/encyclopedia/islands.html

Formation of mountains: Plates smash together, but one goes under the other, and rocks or slabs are push into the air and a mountain is formed.

http://wonderopolis.org/wonder/how-are-mountains-made/