Middle America: Landforms

Most of the Caribbean Islands and the mountainous backbone of Mainland Middle America were formed during 2 mountain building periods. The first occurred around 70 million years ago forming the mountains of western Mexico and Central America and the low-lying outer islands of the Lesser Antilles.

DESCRIPTION OF LANDFORMS

The mountains of Middle America can be seen on the climate and elevation maps of the Middle America [mmclimat] [mmeleves]. These include the Sierra Madre mountains of Mexico [mmphys] which continue in a nearly unbroken mountain chain through Central America to South America. [mmeleves]. Two "breaks" in this mountain chain were considered for a canal to connect the Caribbean Sea with the Pacific Ocean. One is in Nicaragua [mmnicelv] and one is in Panama [mmpanelv].

WHY?

To understand the basic physical structure of Middle America one must have an understanding of plate tectonics. (For a longer discussion of plate tectonics see: http://pubs.usgs.gov/publications/text/dynamic.html

The earth's crust is made of of several pieces called "plates" [world plates] that move very slowly. Originally this was called the Theory of Continental Drift [drift]. Collisions of these plates can form trenches and mountains and can also result in earthquakes and volcanoes. The world's location of earthquakes [quakes] correspond well with these plate boundaries. Also, the volcanic mountains which encircle the Pacific Ocean, which are often referred to as the "Ring of Fire" [ringfire] are closely associate with plate boundaries [world plates].

Seven plates can be found in Latin America [seven]. Collisions of these plates result in subduction [subduction] zones forming trenches and adjacent mountains. In Latin America the Peru-Chile trench along western South America is associated with the Andes Mountains. The Central American trench [trenches] along the Pacific coast is associated with the mountainous backbone of that region. Here the Cocos Plate [seven] is being subducted [subduction] under the Carribean and North American Plates forming the volcanic mountains of Mexico and Central America [mmeleves].

In the Caribbean, the Cayman trench and Puerto Rican Trench [seven] is found along the collision boundary of the Caribbean and North American Plates. Subduction zones in these areas create the trenches and submerged mountains.