The lowlands provide the only livable areas in Iceland. Grass grows there, and the people can raise sheep and some food crops. Part of the Gulf Stream flows around the southern and western coasts and parts of the northern coast, warming the lowlands and keeping the ports free of ice all year long. Summers are mild, and winters are cool. It makes the plateau a land of violent natural wonders, including volcanoes, hot springs, steaming geysers, glaciers, and glistening lava fields.
Earthquakes are fairly common.
More than 200 volcanoes have erupted in Iceland, spreading lava and rocks over the plateau. Some of the volcanoes are still active, including Hekla, a volcano that is well known for its large eruption in 1947 and 1948. There are also active volcanoes under the sea off the Icelandic coasts. One of them erupted in 1963 south of Iceland and formed a new island called Surtsey. In 1973, a volcano that had been dormant for more than 5,000 years erupted on the island of Heimaey, south of Iceland.