Bartholome Islet
The Galapagos have often been described as islands born of fire, which reflects their special origin and violent recent history. They are a chain of oceanic, volcanic islands that came into formation way out in the Pacific Ocean, over 600 nautical miles from the nearest mainland. They are located on an oceanic tectonic plate, the Nazca plate, and have thus never been part of the mainland. Islands can be classified into two groups. Continental islands are located close to a continental landmass, separated from it by relatively shallow waters and joined to it during periods of low sea levels. These land bridges of the ice ages have meant that continental islands started off their island life with a full complement of flora and fauna, which would gradually become depleted over time due to the reduction in surface area. Oceanic islands like Galapagos and Hawaii, on the other hand, are the tips of huge submerged volcanoes that eventually broke the water’s surface to great islands. These oceanic islands started off life as sterile, barren stretches of basaltic lava, completely devoid of all life forms. The latter had to brave the enormous physical barrier constituted by the Pacific Ocean in order to settle on the archipelago, truly no mean feat in an environment as hostile as this one.
These huge volcanoes are the result of an ancient and very active hotspot found under the Earth’s crust. Hotspots are a yet poorly understood phenomenon that causes plumes of magma to rise to the surface, breaking through the overlying tectonic plate. As the latter continues its movement (to the south-east in the case of Galapagos) over the fixed hotspot, a trace of magma builds up to forms chains of these oceanic islands – scenes of rich oases in the middle of an ocean and strange, fantastic life forms evolved in total isolation.
Signs of this past are everywhere to be seen, particularly on today’s visit. Our morning was spent on the islet of Bartholome, in the central part of the archipelago where the main volcanoes are approximately 1.7 million years old. This tiny islet is made up of small parasitic cones that arose in the sea near the island of Santiago. Being in the rain shadow of two larger islands, very little vegetation colonized this area, and it is a perfect illustration of the volcanic past of the area. We had a wonderful morning here, before setting off to spend the afternoon on Santiago Island, fourth largest among the volcanoes.
The Galapagos have often been described as islands born of fire, which reflects their special origin and violent recent history. They are a chain of oceanic, volcanic islands that came into formation way out in the Pacific Ocean, over 600 nautical miles from the nearest mainland. They are located on an oceanic tectonic plate, the Nazca plate, and have thus never been part of the mainland. Islands can be classified into two groups. Continental islands are located close to a continental landmass, separated from it by relatively shallow waters and joined to it during periods of low sea levels. These land bridges of the ice ages have meant that continental islands started off their island life with a full complement of flora and fauna, which would gradually become depleted over time due to the reduction in surface area. Oceanic islands like Galapagos and Hawaii, on the other hand, are the tips of huge submerged volcanoes that eventually broke the water’s surface to great islands. These oceanic islands started off life as sterile, barren stretches of basaltic lava, completely devoid of all life forms. The latter had to brave the enormous physical barrier constituted by the Pacific Ocean in order to settle on the archipelago, truly no mean feat in an environment as hostile as this one.
These huge volcanoes are the result of an ancient and very active hotspot found under the Earth’s crust. Hotspots are a yet poorly understood phenomenon that causes plumes of magma to rise to the surface, breaking through the overlying tectonic plate. As the latter continues its movement (to the south-east in the case of Galapagos) over the fixed hotspot, a trace of magma builds up to forms chains of these oceanic islands – scenes of rich oases in the middle of an ocean and strange, fantastic life forms evolved in total isolation.
Signs of this past are everywhere to be seen, particularly on today’s visit. Our morning was spent on the islet of Bartholome, in the central part of the archipelago where the main volcanoes are approximately 1.7 million years old. This tiny islet is made up of small parasitic cones that arose in the sea near the island of Santiago. Being in the rain shadow of two larger islands, very little vegetation colonized this area, and it is a perfect illustration of the volcanic past of the area. We had a wonderful morning here, before setting off to spend the afternoon on Santiago Island, fourth largest among the volcanoes.
