Central America

I

Introduction

Central America, region of the western hemisphere, made up of a long, tapering isthmus that forms a bridge between North and South America. Central America, which is defined by geographers as part of North America, has an area of about 521,500 sq km (about 201,300 sq mi) and includes the countries of Guatemala, Belize, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama. The region has a population of approximately 36.4 million (2000 estimate).

II

The Natural Environment

In strictly geological terms, Central America begins at the narrow Isthmus of Tehuantepec, in southern Mexico. That narrow section divides the volcanic rocks to the northwest from the folded and faulted structures of Central America. The southernmost geological limit of Central America is the Atrato River valley, in Colombia, South America, just east of the Panama border.

A

Geologic History

Central America, a particularly unstable region of the earth’s crust, is on the western edge of the Caribbean plate (see Plate Tectonics). Subduction of oceanic crust beneath this edge, beginning in the Miocene Epoch, about 25 million years ago, has lifted the land from the sea. In the earliest stage, a peninsula and archipelago formed. Later, about three million years ago, the scattered islands coalesced to form a true land bridge, or isthmus, linking North and South America.

Keeping pace with subduction and uplift have been volcanic eruptions—Central America has at least 14 active volcanoes—and frequent earthquakes. In this century alone, Managua, the capital of Nicaragua, has twice been destroyed by earthquakes. The most recent, in 1972, took 10,000 lives. In 1976 some 25,000 people were killed in an earthquake registering 7.5 on the Richter scale and centered in the Motagua depression in Guatemala. This quake left 25 percent of the country’s population homeless. Volcanic activity has produced a landscape dotted with majestic cones built from eruptions of ash and lava, and beautiful lakes formed in collapsed volcanic craters called calderas.

---

---

B

Natural Regions

For the most part Central America is a rugged, mountainous area, with 109 large volcanoes, some more than 4,000 m (13,000 ft) high; Tajumulco Volcano, in Guatemala, is the highest at 4,220 m (13,845 ft). Central America is one of the most active volcanic zones in the western hemisphere. The land surface slopes up rather abruptly from a narrow coastal plain along the Pacific Ocean to the mountain crests, and then descends more gradually to a broader plain along the Caribbean Sea. Two major interoceanic passes cut through the highlands of Central America, one in Nicaragua (from the mouth of the San Juan River to Lake Nicaragua) and the other in Panama (along the route of the Panama Canal). The Pacific coastline is about 2,830 km (about 1,760 mi) long, and the Caribbean coastline is approximately 2,740 km (approximately 1,700 mi) long. Several groups of small islands lie off the Caribbean coast, and some of them, such as the Bay Islands (Islas de la Bahía) in the Gulf of Honduras, are inhabited.

	More from Encarta
	•  7 tips for funding an online degree •  How to succeed in the fashion industry without being a top designer •  Presidential Myths Quiz •  Coffee break: Recharge your brain