They are an archipelago of volcanic islands scattered around the equator in the Pacific Ocean. Part of continental Ecuador lying 972 km (525 nmi) west of it, Galapagos Islands are geologically young and home for various number of endemic species. Observations on these species lead to the rise of theories like the inception of Darwin's theory of evolution by natural selection. The exact location is found in the eastern Pacific Ocean, 973 km (525 nmi; 605 mi) off the west coast of South America. The closest is the mainland of Ecuador to the east, to the north is Cocos Island at 720 km (389 nmi; 447 mi) and to the south is Easter Island and San Felix Island at 3,200 km (1,730 nmi; 1,990 mi).
The Galápagos Archipelago consists of 7,880 km2 (3,040 sq mi) of land spread over 45,000 km2 (17,000 sq mi) of ocean. The largest of the islands, Isabela, measures 4,640 km2 (1,790 sq mi) and makes up half of the total land area of the Galápagos. Volcán Wolf on Isabela is the highest point, with an elevation of 1,707 m (5,600 ft) above sea level. The island chain consists of 15 main islands, 3 smaller islands, and 107 rocks and islets. The archipelago is located on the Nazca tectonic plate, which is moving east/southeast, diving under the South American Plate at a rate of about 2.5 inches per year. It is also atop the Galapagos hotspot, a place where the Earth's crust is being melted from below by a mantle plume, creating volcanoes. The oldest island is thought to have formed between 5 million and 10 million years ago. The youngest islands, Isabela and Fernandina, are still being formed, with the most recent volcanic eruption in April 2009, where lava from the volcanic island Fernandina started flowing both towards the island's shoreline and into the centre caldera.
Among the islands, Baltra Island which is also known as South Seymour, Baltra is a small flat island located near the centre of the Galápagos. It was created by geological uplift. The island is very arid, and vegetation consists of salt bushes, prickly pear cacti and palo santo trees. During the 1940s, scientists decided to move 70 of Baltra's land iguanas to the neighboring North Seymour Island as part of an experiment. This gave unexpected results during the military occupation of Baltra in World War II; the native iguanas became extinct on the island. During the 1980s, iguanas from North Seymour were brought to the Charles Darwin Research Station as part of a breeding and repopulation project, and in the 1990s, land iguanas were reintroduced to Baltra. As of 1997, scientists counted 97 iguanas living on Baltra; 13 of which were born on the islands.
Another island is Bartolomé Island which is a volcanic islet just off the east coast of Santiago Island in the Islands group. It is one of the "younger" islands in the Galápagos archipelago. This island and neighboring Sulivan Bay on Santiago Island are named after life-long friend of Charles Darwin, Sir Bartholomew James Sulivan, who was a Lieutenant aboard HMS Beagle. This island is one of the few that is home to the Galapagos penguin which is the only wild penguin species to live on the equator. The green turtle is another animal that resides on the island.
Darwin Island which is named after Charles Darwin has an area of 1.1 square kilometers (0.4 sq mi) and a maximum altitude of 168 meters (551 ft). Here fur seals, frigates, marine iguanas, swallow-tailed gulls, sea lions, whales, marine turtles can be seen. Another island is Española Island whose name was given in honor of Spain. It has an area of 60 square kilometers (23 sq mi) and a maximum altitude of 206 meters (676 ft). Because of its remote location it has the largest number of endemic species. It has its own species of lava lizard, mockingbird, and tortoise. Española is the only place where the waved albatross nests.
Fernandina Island’s name was given in honor of King Ferdinand II of Aragon, who sponsored the voyage of Columbus. Fernandina has an area of 642 square kilometers (248 sq mi) and a maximum altitude of 1,494 meters (4,902 ft). On 13 May 2005, a new, very eruptive process began on this island, when an ash and water vapor cloud rose to a height of 7 kilometers (23,000 ft) and lava flows descended the slopes of the volcano on the way to the sea. Punta Espinosa is a narrow stretch of land where hundreds of marine iguanas gather, largely on black lava rocks. The famous flightless cormorants inhabit this island, as do Galápagos penguins, pelicans, Galápagos sea lions and Galápagos fur seals. Different types of lava flows can be compared, and the mangrove forests can be observed.
Among the other islands are, Floreana (Charles or Santa María) Island, Genovesa (Tower) Island, Marchena (Bindloe) Island, Pinzón (Duncan) Island, Pinta (Abingdon) Island, Rábida (Jervis) Island, San Cristóbal (Chatham) Island, Santa Cruz (Indefatigable) Island, Santa Fé (Barrington) Island, Santiago (San Salvador, James) Island, Wolf (Wenman) Island are the main islands we find. Among the minor islands, Daphne Major which is a small island directly north of Santa Cruz and directly west of Baltra, South Plaza Island which includes Opuntia cactus and Sesuvium plants that form a reddish carpet on top of the lava formations and Nameless Island – A small islet used mostly for scuba diving are prominent.
The Humboldt Current brings cold water to the islands, causing frequent drizzles during most of the year. The weather is periodically influenced by the El Niño phenomenon, which brings warmer temperatures and heavy rains. Temperature decreases gradually with altitude, while precipitation increases due to the condensation of moisture in clouds on the slopes. There is a large range in precipitation from one place to another, not only with altitude, but also depending on the location of the islands, and also with the seasons. The precipitation also depends on the geographical location.
These islands were first ever appeared on the maps, of Gerardus Mercator and Abraham Ortelius, in about 1570.The islands were named "Insulae de los Galopegos" because of giant tortoises found there. Until the early 19th century, the archipelago was often used as a hideout by mostly English pirates who pilfered Spanish galleons carrying gold and silver from South America to Spain. In 1793, James Clonett suggested the islands could be used as base for the whalers operating in the Pacific Ocean. He drew the first accurate navigation charts of the islands. Whalers and maritime fur trader killed and captured thousands of the Galápagos tortoises to extract their fat. The tortoises could be kept on board ship as a means of providing of fresh protein, as these animals could survive for several months on board without any food or water. The hunting of the tortoises was responsible for greatly diminishing, and in some cases eliminating, certain species. Along with whalers came the fur-seal hunters, who brought the population of this animal close to extinction.
The survey ship HMS Beagle came to the Galápagos on 15 September 1835, along with the young naturalist Charles Darwin who made observations on the geology and biology on Chatham, Charles, Albemarle and James islands before they left on 20 October to continue on their round-the-world expedition. Darwin was impressed by the quantity of volcanic craters they saw, later referring to the archipelago as "that land of craters." His study of several volcanic formations led to several important geological discoveries, including the first, correct explanation for how volcanic tuff is formed. Darwin noticed the mockingbirds differed between islands and the Englishman Nicolas Lawson, acting Governor of Galápagos for the Republic of the Equator told Darwin the tortoises differed from island to island. Speculating the facts and his specimens he brought back home, Darwin developed his theory of natural selection explaining evolution, which was presented in the book The Origin of Species.
The Galápagos became a national park in 1959, and tourism started in the 1960s, imposing several restrictions upon the human population already living on the island. However, opportunities in the tourism, fishing, and farming industries attracted a mass of poor fishermen and farmers from mainland Ecuador. In the 1990s and 2000s, violent confrontations between parts of the local population and the Galapagos National Park Service occurred, including capturing and killing giant tortoises and holding staff of the Galapagos National Park Service hostage to obtain higher annual sea cucumber quotas.
Introduced animals and plants like cattle, feral goats became a threat to the native ones in the islands giving rise to problems like competition for food and symbiosis. Some of the most harmful introduced plants are the guava (Psidium guajava), avocado (Persea americana), cascarilla (Cinchona pubescens), balsa (Ochroma pyramidale), hill raspberry (Rubus niveus), various citrus (orange, grapefruit, lemon), floripondio, higuerilla (Ricinus communis) trees and the elephant grass, Pennisetum purpureum. These plants have invaded large areas and eliminated endemic species in the humid zones of San Cristobal, Floreana, Isabela and Santa Cruz.
Non-native goats, pigs, dogs, rats, cats, mice, sheep, horses, donkeys, cows, poultry, ants, cockroaches, and some parasites inhabit the islands today. Dogs and cats attack the tame birds and destroy the nests of birds, land tortoises, and marine turtles. They sometimes kill small Galápagos tortoises and iguanas. Pigs are even more harmful, covering larger areas and destroying the nests of tortoises, turtles and iguanas, as well as eating the animals' native food. Pigs also knock down vegetation in their search for roots and insects. This problem abounds in Cerro Azul volcano and Isabela, and in Santiago, pigs may be the cause of the disappearance of the land iguanas that were so abundant when Darwin visited. The black rat (Rattus rattus) attacks small Galápagos tortoises when they leave the nest, so in Pinzón they stopped the reproduction for a period of more than 50 years; only adults were found on that island.
Map of Galápagos Islands
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