North America

North America

North America is the third largest continent in the world by land area. By population, it is the fourth largest. Sometimes considered to be a subcontinent of the Americas, North America is found entirely in the northern hemisphere and is bordered by the Arctic Ocean in the north, the Atlantic ocean in the east, the Pacific Ocean in the west, and South America to the south. North America is home to the longest land border in the world, which is shared between Canada the the United States.

The climate of North America is warmer in the south of the continent, and colder in the north. While temperatures near the coast tend to be mild, inland temperatures can experience extremes. While the southern portion of the continent, in the southern United States and Central America, is subtropical, the northern portion of the continent consists largely of Arctic tundra.

The United States is the most populated country in North America, followed by Mexico. The people of North America are ethnically diverse. English, Spanish, and French are the most commonly spoken languages on the continent, although there are a number of minority languages as well.

North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 16.5% of the earth's land area and about 4.8% of its total surface. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in 23 independent states, or about 7.5% of the world's population, if nearby islands (most notably the Caribbean) are included.

North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge approximately 40,000 to 17,000 years ago. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago (the beginning of the Archaic or Meso-Indian period). The Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended in 1492, with the beginning of the transatlantic migrations—the arrival of European settlers during the Age of Discovery and the Early Modern period. Present-day cultural and ethnic patterns reflect interactions between European colonists, indigenous peoples, African slaves and their descendants.

History

Laurentia is an ancient craton which forms the geologic core of North America; it formed between 1.5 and 1.0 billion years ago during the Proterozoic eon. The Canadian Shield is the largest exposure of this craton. From the Late Paleozoic to Early Mesozoic eras, North America was joined with the other modern-day continents as part of the supercontinent Pangaea, with Eurasia to its east. One of the results of the formation of Pangaea was the Appalachian Mountains, which formed some 480 million years ago, making it among the oldest mountain ranges in the world. When Pangaea began to rift around 200 million years ago, North America became part of Laurasia, before it separated from Eurasia as its own continent during the mid-Cretaceous period. The Rockies and other western mountain ranges began forming around this time from a period of mountain building called the Laramide orogeny, between 80 and 55 million years ago. The formation of the Isthmus of Panama that connected the continent to South America arguably occurred approximately 12 to 15 million years ago, and the Great Lakes (as well as many other northern freshwater lakes and rivers) were carved by receding glaciers about 10,000 years ago.

Geography

North America occupies the northern portion of the landmass generally referred to as the New World, the Western Hemisphere, the Americas, or simply America (which, less commonly, is considered by some as a single continent with North America a subcontinent). North America's only land connection to South America is at the Isthmus of Darian/ Isthmus of Panama. The continent is delimited on the southeast by most geographers at the Darién watershed along the Colombia-Panama border, placing almost all of Panama within North America. Alternatively, some geologists physiographically locate its southern limit at the Isthmus of Tehuantepec, Mexico, with Central America extending southeastward to South America from this point. The Caribbean islands, or West Indies, are considered part of North America. The continental coastline is long and irregular. The Gulf of Mexico is the largest body of water indenting the continent, followed by Hudson Bay. Others include the Gulf of Saint Lawrence and the Gulf of California.

Geology

Geologically, Canada is one of the oldest regions in the world, with more than half of the region consisting of precambrian rocks that have been above sea level since the beginning of the Palaeozoic era. Canada's mineral resources are diverse and extensive. Across the Canadian Shield and in the north there are large iron, nickel, zinc, copper, gold, lead, molybdenum, and uranium reserves. Large diamond concentrations have been recently developed in the Arctic, making Canada one of the world's largest producers. Throughout the Shield there are many mining towns extracting these minerals. The largest, and best known, is Sudbury, Ontario. Sudbury is an exception to the normal process of forming minerals in the Shield since there is significant evidence that the Sudbury Basin is an ancient meteorite impact crater. The nearby, but less known Temagami Magnetic Anomaly has striking similarities to the Sudbury Basin. Its magnetic anomalies are very similar to the Sudbury Basin, and so it could be a second metal-rich impact crater. The Shield is also covered by vast boreal forests that support an important logging industry.

Climate

North America is a very large continent which surpasses the Arctic Circle, and the Tropic of Cancer. Greenland, along with the Canadian Shield, is tundra with average temperatures ranging from 10 to 20 °C (50 to 68 °F), but central Greenland is composed of a very large ice sheet. This tundra radiates throughout Canada, but its border ends near the Rocky Mountains (but still contains Alaska) and at the end of the Canadian Shield, near the Great Lakes. Climate west of the Cascades is described as being a temperate weather with average precipitation 20 inches (510 mm). Climate in coastal California is described to be Mediterranean, with average temperatures in cities like San Francisco ranging from 57 to 70 °F (14 to 21 °C) over the course of the year.

Economy

North America's GDP per capita was evaluated in October 2016 by the International Monetary Fund (IMF) to be $41,830, making it the richest continent in the world, followed by Oceania.

Canada, Mexico, and the United States have significant and multifaceted economic systems. The United States has the largest economy of all three countries and in the world. In 2016, the U.S. had an estimated per capita gross domestic product (PPP) of $57,466 according to the World Bank, and is the most technologically developed economy of the three. The United States' services sector comprises 77% of the country's GDP (estimated in 2010), industry comprises 22% and agriculture comprises 1.2%. The U.S. economy is also the fastest growing economy in North America and the Americas as a whole, with the highest GDP per capita in the Americas as well.