Southward from its 1,500 mile long border with the United States lies the
Estados Unidos Mexicanos. A country with slightly more than 750,000 square miles in
area, Mexico has a vast array of mineral resources, limited agricultural land, and
a rapidly growing population. These factors are the basis for many of the country's
present problems as well as opportunities for future development. The nation is
struggling to modernize its economy. 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 inhabitants live in the country's central core, while the arid north
and the tropical south are sparsely settled.
The stereotype of Mexico is that it is a country with a population consisting
mainly of subsistence farmers has little validity. Petroleum and tourism dominate
the economy, and industrialization is increasing in many parts of the nation.
Internal migration from the countryside has caused urban centers to grow
dramatically: more than two thirds of all Mexicans now live in cities. Mexico City,
with a metropolitan area population of approximately 16 million people, is the
largest city in the world. While still low by United States standards, the nation's
gross national product per capita rose significantly during the 1970s. Despite
impressive social and economic gains, since 1981 Mexico has been wracked by severe
inflation and an enormous foreign debt brought on in large part by precipitous
declines in the value of petroleum products.
Geologically, Mexico is located in one of the Earth's most dynamic areas. It
is a part of the "Ring of Fire," a region around the Pacific Ocean highlighted by
active volcanism and frequent seismic activity. Within the context of plate
tectonics, a theory developed to explain the creation of major landform features
around the world, Mexico is situated on the western, or leading, edge of the huge
North American Plate. Its interaction with the Pacific, Cocos, and Caribbean plates
has given rise over geologic time to the Earth-building processes that created most
of Mexico. Towering peaks, like Citlaltepetl at some 18,000 feet, are extremely
young in geologic terms and are examples of the volcanic forces that built much of
central Mexico. The spectacular eruption of the volcano Chinchon in 1981 was more
powerful than that of Mount St. Helens in the United States a year earlier and led
to widespread devastation.
Much of the complexity found in southern Mexico's physiography is related to
the interaction of three tectonic plates. Such interaction creates regions that are
often highly unstable, producing numerous and severe Earth movements. A 1985 quake,
with an epicenter off the coast of Acapulco, caused billions of dollars in damage
nationwide, destroyed hundreds of buildings in Mexico City, and killed several
thousand people. It is on this often unstable and dynamically active physical
environment that the Mexican people must build their nation.
The plateau can be subdivided into two major sections. The Mesa del Norte