Mexico

Mexico is a county with more than 750,000 square miles in area and has many mineral resources, limited agricultural land, and a rapidly growing population. These factors are the reasons for many of the country's present problems and problems of future development. With more than 80 million people in the mid-1980s, Mexico's overall population density exceeds 110 per square mile. More than half of its people live in the central part of the county, while the north and south are barely settled.

Unlike the stereotype of a country with a population mainly of farmers, Mexico petroleum and tourism dominate the economy, causing industrialization to increasing in many parts of the county. People moving from the country to central Mexico puts over two thirds of the countries people in the major cities of Mexico. Mexico City, with a population of about 16 million people, is the largest city in the world. Despite social and economic gains, since 1981 Mexico has had to deal with severe inflation and a huge foreign debt due to the declines in the value of petroleum products.

Geologically, Mexico is one of the most diverse areas. It is a part of the "Ring of Fire," a area around the Pacific Ocean surrounded by active volcanos and frequent seismic activity. This activety shaped the

The plateau can be subdivided into two major sections. The Mesa del Norte begins near the international border and ends around San Luis Potosi. In this arid lower part of the plateau, interior drainage predominates with few permanent streams. On its west side the mesa is flanked by the largely volcanic Sierra Madre Occidental, with an average height of 8,000 to 9,000 feet 2,400 to 2,700 meters . It has been highly dissected by westward-flowing streams that eroded a series of deep barrancas, or canyons. The most spectacular of these is the Barranca del Cobre, Mexico's equivalent of the Grand Canyon. The Sierra Madre Oriental, a range of folded mountains formed of shale and limestone, is on the east side of the mesa. With average elevations similar to those of the Sierra Madre Occidental, these dissected highlands have peaks that reach 13,000 feet.

The Mesa Central stretches from San Luis Potosi to the volcanic axissouth of Mexico City. Formed largely by volcanic action, the general plateau surface of this mesa is higher, moister, and generally flatter than the Mesa del Norte. The Mesa Central is divided into a series of fairly flat rmountain basins separated by eroded volcanic peaks. These basins are generally fertile and have been the most densely populated portions of Mexico for several hundred years. The largest valleys such as those of Mexico City, Puebla, and Guadalajara rarely exceed 100 square miles in area, while many others are quite small. The traditional breadbasket of the country, the Bajio of Guanajuato, islocated in the northern part of the mesa. Many of the basins were sites of major lakes, like those formerly located around Mexico City that were drained to facilitate European settlement. The weak, structurally unstable soils that remain have caused numerous buildings to shift on their foundations and over many years to slowly sink into the ground. The volcanic axis with such spectacular snowcapped peaks as Popocatepetl at 17,887 feet, Ixtaccihuatl at 17,342 feet, and Toluca at 15,000 feet forms the southern boundary of the Mexican Plateau.

On the east and west sides of the plateau lie that country's coastal lowlands. The Gulf Coastal Plain extends from the Texas border to the Yucatan peninsula, a distance of some 900 miles. Characterized by lagoons and low-lying swampy areas, the triangular northern portion is more than 100 miles wide near the border and tapers rapidly toward the south. Inland toward the abrupt escarpment of the Sierra Madre Oriental is a series of gently undulating plains dotted by occasional hills and low mountains. Near Tampico an extension of the Sierra Madre Occidental reaches the sea and interrupts the plain's continuity. To the south of Tampico it is narrow and irregular. In several places low hills and isolated volcanic peaks meet the sea and subdivide the plain. It widens at the northern end of the Isthmus of Tehuantepec and then encompasses the limestone formations that underlie the Yucatan peninsula.

Because of its topographic diversity and large range in latitude, Mexico has a wide array of climatic conditions, often occurring in very short distances. More than half of Mexico lies south of the Tropic of Cancer. Within the tropics, temperature variations from season to season are small, often less than 10 F between the warmest and coldest months of the year. In these areas winter is defined as the rainiest rather than coldest months. The climate also changes significantly with increases in elevation..

The natural wildlife of northern Mexico was severely affected by the introduction