سؤال قراءة ستيب محلول — فهم التفاصيل (تدريب 4736)

(1) The formation of the Hawaiian Islands was very different from the formation of the continents. Geologists believe that the islands appeared separately and more recently. According to the geological evidence, they were formed by volcanoes only about 30 million years ago. (2) These volcanoes began when some cracks appeared on the bottom of the Pacific Ocean. Deep under the earth's surface, the rocks are very hot, so hot that they are in a liquid from called lava. This lava can sometimes come up through openings on the surface of the earth. The piles of lava slowly build up and become mountains. When the openings are on the ocean floor, the mountains are at first underwater. They may eventually become tall enough to rise above the water and form islands. This is how the Hawaiian Archipelago was created. (3) Younger Hawaiian Islands are still growing. The Big Island of Hawaii has two active volcanoes which are still adding new lava to the island. There are also new islands in the archipelago in the process of formation. Geologists have found an underwater volcano about 30 miles south of the island of Hawaii. Now about 3.000 feet below the surface of the ocean, it will probably rise above the water. Someday, this volcano could become another Hawaiian island.