Darwin Island
Darwin Island (Spanish: Isla Darwin) is named in honor of Charles Darwin, and is among the smallest in the Galapagos Archipelago with an area of just one square kilometer. With no dry landing sites, Darwin Island's main attractions are found in the Pacific Ocean, which is teeming with a spectacular variety of marine life. Darwin Island and Wolf Island sometimes are referred to as Darwin and Wolf or Darwin Wolf.
Although the island had been marked on maps, and initially had been given the name Culpepper Island on Admiralty charts, the first visit onto Darwin Island was not until 1964 using a helicopter. [1]
Geology
Darwin Island is the remains of an extinct volcano that reaches 165 meters above sea level, it is situated north west of the main Galapagos Island group on the Wolf-Darwin Lineament that extends from the Galapagos Platform to the Galapagos Spreading Center, a mid ocean ridge separating the Nazca and Cocos tectonic plates. The formation of Darwin Island is different from the formation of the main Galapagos Islands. There are currently two theories on the formation of the lineament: the first is that magma rising from the mantle plume forming the main Galapagos Islands has been channelled towards the Galapagos Spreading Center; alternatively there has been a separate rise in magma caused by stress in the ocean lithosphere by a transform fault. [2]
Darwin Island is the most northerly of the two peaks on the Wolf Darwin Lineament that reach above the surface, the other island Wolf Island is approximately 40 km away, although there are other sub surface peaks. The volcano that forms the island is extinct, with the last eruption believed to have been approximately 400,000 years ago,. [3] making it younger than Wolf. The lava flows around Darwin are homogenous, believed to be because of its young age and have a similar chemical composition to those of the Galapagos Spreading Center.[4].
Darwin is believed to have had at least two eruptive periods in its history of two tuff layers separated by plagioclase ultraphyric basalt. Evidence also exists to suggest that Darwin Island is the remains of what was once a much larger edifice. [4] Since the eruptive phase this would have been eroded.
Darwin Arch is a natural rock arch would at one time been part of this larger structure is located less that a kilometre from the main Darwin Island is a well known landmark to the few visitors to the island.
Wildlife
Darwin Island is not open to land visits. As a result the only visitors are those that come to scuba dive, even here due to the distance from the main island only a limited number of liveaboard ships cruise here. The marine life at Darwin is diverse with large schools of fish. The island’s waters attract Whale Sharks from June to November, as well Hammerhead, Galapagos, Silky and Blacktip sharks. In addition Green Turtles, Manta rays and dolphins can be found. [5]
The island also supports a large bird population, including Frigate Birds and Red-footed Booby birds.
References
- ^ [Ecuador & the Galápagos Islands By Danny Palmerlee, Michael Grosberg, Carolyn McCarthy ISBN174104295X]
- ^ Blair et al., Plume Ridge Interaction
- ^ Cornell University
- ^ a b Role of Plume-Ridge Interaction in Magma Genesis III: Darwin Island
- ^ Galapagos National Park Interactive Map