9781422286456

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Peru

sea level to 3,281 feet (1,001 meters). Although the coastal strip is mainly arid, seasonal rains occur in the north—especially during a weather pattern known as El Niño. El Niño occurs every three to seven years when unusually warm ocean conditions appear along the western coast of South America. During El Niño, the wet weather conditions off Peru and Ecuador move east, bringing heavy rains that can cause extensive flooding. Usually, however, the Peruvian coast receives less than two inches (5 centimeters) of rain each year. This is because most of the moisture carried by the eastern trade winds falls on the cordilleras . But many of Peru’s 52 valleys are arable . They are farmed using a combination of ancient Indian irrigation methods and modern technologies. In addition, warm, foggy clouds known as garúa shroud many of the foothills of the sierra from June to October, providing enough moisture to support grasslands. arable— fit for growing crops. arid— extremely dry. cordillera— a system of mountain ranges, often consisting of a number of parallel chains. costa— Spanish word meaning “coast”; one of three natural regions in Peru. navigable— capable of being traveled by ships and boats. rain forest— a forest that receives at least 100 inches (254 cm) of rain per year. sierra— a range of mountains, especially one with an irregular outline. temperate— having a mild or moderate climate. trade winds— winds that blow almost constantly in one direction near the equator. Words to Understand in this Chapter