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The Galapagos archipelago
country : Ecuador
place : off the west coast of the country


The Galapagos Archipelago is situated 800 kilometers west of the Ecuadorian coast and lie directly on the equator. The archipelago encompasses over 50 islands of volcanic origin that are spread out over an area of about 4,500 square kilometers. The volcanic Galapagos platform originated probably not more than 15 million years ago and the oldest island not more than 2.4 million years ago. Volcanic eruptions still occur in the islands. Isla Fernandina and the Sierra Negra volcano on Isla Isabela have erupted within the past 10 years.


The Galapagos Islands are an archipelago consisting of some 16 islands and numerous islets scattered over an area of nearly 36,000 square miles around the Equator. Each major island, with the exception of the largest island, Isabela, consists of a single large shield volcano. Isabela was formed from six volcanoes joined above sea level. The total land area of all the islands, islets and rocks that form the Galapagos Islands is about 3,028 square miles, with Isabela making up more than half the total land area, at 1,700 square miles. The islands all rose from the ocean floor as the tops of volcanoes, possibly during the Pliocene era, and have never been connected by land to any mainland area. Today, the Galapagos Islands remain one of the most active oceanic volcano areas on Earth.


Just as the extraordinary wildlife of the Galapagos Islands is critical to the study of biology, the unique geology of the islands has implications for the whole planet. In geological terms, the Galapagos Islands are quite young, probably no more than five million years old. Some of the westernmost islands, which are the most volcanically active, may only be hundreds of thousands of years old and are actually still forming. Fernandina, for example, at its current rate of activity, may one day expand to meet the shores of Isabela, creating a single, large island. As these amazing changes take place, scientists can observe the effects of the tides, wind and weather on the process. They are then better able to define the impact of the environment on both the Galapagos Islands and, by extension, the Earth. More importantly, these studies can help scientists develop ways to protect the environment in our ever-changing world.




Though the islands are now quite isolated, at 600 miles from the nearest mainland, some biologists believe that the Cocos Ridge, which runs under the sea and extends almost the entire distance from Costa Rica to the northern islands, was once a land bridge. These biologists use this theory to explain how some of the life on the Galapagos Islands arrived there, but it has not yet been proven. Although many species of flora and fauna that thrive on the Galapagos Islands resemble those native to South America, they have evolved so extensively in isolation that they now appear very different from their mainland ancestors.




There are four main ecosystems in the Galapagos Islands, which have been formed over time by wind patterns and differences in elevation. The first ecosystem is made up of arid lowlands and open forests of enormous cacti; the second consists of subtropical forests; the third, found at higher elevations, is composed of moist, dense forests; and treeless upland areas covered with ferns and grasses make up the fourth. Goats, pigs, and other introduced species left by 19th century sailors to multiply on the islands and serve as a source of fresh meat on later visits eventually destroyed much of the native vegetation on many of the islands. The remaining areas consist of little more than bare, hardened lava, which has formed cliffs and jagged points of land along the coasts. Volcanic activity has produced several thousand calderas and cones throughout the archipelago, the largest of which may be found on the islands of Isabela and Fernandina. These unusual landforms give the landscape of some islands an almost lunar quality.





































 

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