阅读理解
Glacier Bay is one of the most famous parks in America, located in the state of Alaska. This park in the southeastern part of the state covers more than 1 million hectares of Alaskan wilderness. It includes mountains, glaciers (冰川), bays, and even rainforests. Glacier Bay supports hundreds of kinds of animals, including many species of birds, fish, bears, whales and sea lions.
As its name suggests, much of Glacier Bay National Park is covered by glaciers. A glacier is a large area of ice that moves slowly down a slope (斜坡) or valley, or over a wide area of land. Glaciers cover more than 5,000 square kilometers of the park.
Glacial ice has shaped the land over the last seven million years. The glaciers found in the park today are what remains from an ice advance known as the Little Ice Age. That period began about 4,000 years ago.
During the Little Ice Age, the cold weather caused the ice to grow and advance. That situation continued until about 1,700s, when the climate began to warm. The higher temperatures caused the ice to start melting. That melting led the huge glacier to separate into more than 1,000 different glaciers.
The extremely tall and jagged (参差不齐的) mountains seen in Glacier Bay National Park were formed by the ice advancing and then melting over time. The melting of the ice also created water that filled in and created the many fjords (峡湾) within the park. Fjords are narrow parts of the ocean that sit between cliffs or mountains.
The huge amount of water from the melted ice killed off many kinds of plants. Vegetation returned to the area over the next 200 years. The regrowth in plants also brought back many animals to the land. This return of life to Glacier Bay is why it is sometimes called “a land reborn” by people.
