The youngest, highest, and most densely populated mountain range in Europe, the Alps form a natural barrier between Mediterranean Europe and the rest of the continent. From the French-Italian border region near the Mediterranean Sea, the Alps curve north and northeast to Vienna, Austria. They cover more than 80,000 square miles (207,000 square kilometers) and stretch across nine nations: France, Italy, Switzerland, Germany, Austria, Slovenia, Croatia, Bosnia and Herzegovina, and Serbia and Montenegro.

Origins

The Alps were formed about 44 million years ago. At this time, part of the Earth's crust began to move slowly northward. This movement folded rock at the bottom of the ancient Tethys Sea against mountains in central France, southern Germany, the Czech Republic, and Slovakia. Some folding cracked the Earth's crust. This let molten rock well up to form high, rugged mountains.

Physical features and climate

The highest peak in the Alps is Mont Blanc in France, at 15,771 feet (4,807 meters). Several other high peaks are located on or near the Swiss-Italian border, which is generally the highest Alpine region. These peaks include Dufourspitze, the Matterhorn, and Finsteraarhorn, all more than 14,000 feet (4,267 meters) high.

The Alps receive a great deal of snow and rain. At high elevations, the snow turns to ice and then flows down to the valleys as glaciers. The largest of the Alpine glaciers is Altesh, near the central Alps. On the slopes of Mont Blanc is another well-known glacier, Mer de Glace (Sea of Ice). Sometimes masses of snow rush uncontrolled down the mountainsides as avalanches, endangering Alpine communities. At lower levels the ice and snow melt, feeding the Rhône, Rhine, Danube, and Po rivers.

The clear Alpine lakes are noted for their beauty. Among the most prominent are Lakes Geneva, Constance, Como, and Zürich.

Plants and animals

The Alps are divided into a nearly treeless top zone and a lower forested area. The Alpine turf bears grass, shrubs, and flowers. Mountain meadows, called alpages, spread out above the tree line and below the snow line. These pastures give the range its name. Several kinds of trees grow on the valley floor and lower slopes, including oak, beech, and chestnut. These trees are deciduous, meaning that they lose their leaves in winter. At higher elevations, the forest consists mainly of spruces, firs, and other evergreen trees.

A few animal species have adapted well to the higher mountains. The ibex, a sturdy, nimble goat, survives in Italian preserves. The Alpine marmot, a thick-bodied squirrel, hibernates in burrows. The grouselike mountain hare grows a protective white coat for winter. Alpine countries have established national parks to protect native plants and animals.

People

Humans have lived in the Alps since prehistoric times, 50,000 to 60,000 years ago. German cultures developed in the eastern Alps, while Roman culture influenced the west. The main language groups that survive today are German, French, Italian, and Slovene.

Economy

The ancient Romans built roads through the Alpine passes to the north and the west to promote trade and link their Mediterranean and northern provinces. Economic activity of the period included grape growing, iron ore mining, and pottery manufacturing.

Alpine valleys and many mountainsides were cleared of forests during the Middle Ages. Farmers settled the land, planted crops, and raised cattle. During the 19th century, railroads were constructed, opening up the area. The electric power made by damming the Alpine rivers later encouraged manufacturing.

Tourism became a major Alpine industry during the 20th century as air, auto, and rail transportation to the Alps improved. Winter sports gained popularity as a result of the accessibility of the region. Today entire villages lodge, feed, and entertain tourists. Popular Alpine resorts include Innsbruck, Grenoble, and St. Moritz, all of which have hosted the Olympic Games.

Human impact on the Alps

The popularity of the Alps has caused steady changes to the Alpine environment since the mid-20th century. Increased industrialization and tourism have resulted in air and water pollution, slope erosion, and the destruction of forests by a form of air pollution known as acid rain.