The Earth's Crust is a
Conglomeration of
Several Tectonic Plates
The earths crust is broken up into several large pieces that are referred to as plates. The plates carry continental (land), oceanic (under sea) or both kinds of crust. When oceanic crust ages a subduction develops. (See Subduction Explained.) Subductions may cause tsunamis. If two like kinds of crust collide (in slow motion over millions of years) the edges of the plates heave and crumble. Such events create mountain ranges and valleys, plains, lakes, and waterways.
It is believed that a combination of volcanic activity and massive earthquakes caused the huge sea that covered most of western North America to dump out leaving the salt to dry into the Salt Lake in Utah and creating the Grand Canyon and the Snake River.
The movement of the tectonic plates often coupled to volcanic activity cause massive pressure and may cause shifts and slippage of the plates against, over or under each other.
The plates are in constant movement and that movement creates earthquakes. If you are familiar with the "plate boundaries" it will help you understand the possible effected areas and proactively plan to survive potential Tectonic shifts.
Study the map graphic above. The black lines are designate the plate boundaries. The X's identify hot spots between the plates.
Earth – Seismic / Techtonic Articles
Earthquake Intensity Scale
