Erebus hotspot

The Erebus hotspot is a volcanic hotspot responsible for the high volcanic activity on Ross Island in the western Ross Sea of Antarctica. Its current eruptive zone, Mount Erebus, has erupted continuously since its discovery in 1841.[1]

Magmas erupted from the Erebus hotspot are similar to those erupted from hotspots at the active East African Rift in eastern Africa.[1] Mount Bird at the northernmost end of Ross Island and Mount Terror at its eastern end are large basaltic shield volcanoes that have been potassium-argon dated to be 3.8–4.8 and 0.8–1.8 million years old.[1]

The Erebus hotspot has been interpreted to be the cause of spreading at the Terror Rift.[1] Its mantle plume, estimated to be 250 to 300 km (160 to 190 mi) in diameter, extends 200 km (120 mi) below the surface where it changes into a narrow column that further extends 400 km (250 mi) below the surface.[2]

References

  1. ^ a b c d Morgan, W.J.; Phipps Morgan, J. (2007) "Plate velocities in hotspot reference frame: electronic supplement".
  2. ^ Gupta, Sandeep; Zhaob, Dapeng; Raia, S.S. (August 2009). "Seismic imaging of the upper mantle under the Erebus hotspot in Antarctica". Gondwana Research. 16 (1): 109–118. doi:10.1016/j.gr.2009.01.004.
Geology of Antarctica

The geology of Antarctica covers the geological development of the continent through the Proterozoic Eon, Paleozoic, Mesozoic and Cenozoic eras.

More than 170 million years ago, Antarctica was part of the supercontinent Gondwana. Over time Gondwana broke apart and Antarctica as we know it today was formed around 35 million years ago.

Hotspot (geology)

In geology, the places known as hotspots or hot spots are volcanic regions thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle. Their position on the Earth's surface is independent of tectonic plate boundaries. There are two hypotheses that attempt to explain their origins. One suggests that hotspots are due to mantle plumes that rise as thermal diapirs from the core–mantle boundary. The other hypothesis is that lithospheric extension permits the passive rising of melt from shallow depths. This hypothesis considers the term "hotspot" to be a misnomer, asserting that the mantle source beneath them is, in fact, not anomalously hot at all. Well-known examples include the Hawaii, Iceland and Yellowstone hotspots.

Mount Erebus

Mount Erebus ( ) is the second-highest volcano in Antarctica (after Mount Sidley) and the southernmost active volcano on Earth. It is the sixth-highest ultra mountain on the continent. With a summit elevation of 3,794 metres (12,448 ft), it is located in the Ross Dependency on Ross Island, which is also home to three inactive volcanoes: Mount Terror, Mount Bird, and Mount Terra Nova.

The volcano has been active since about 1.3 million years ago and is the site of the Mount Erebus Volcano Observatory run by the New Mexico Institute of Mining and Technology.The volcano was the site of the Air New Zealand Flight 901 accident, which occurred in November 1979.

Ring of Fire

The Ring of Fire (also known as the Rim of Fire or the Circum-Pacific belt) is a major area in the basin of the Pacific Ocean where many earthquakes and volcanic eruptions occur. In a large 40,000 km (25,000 mi) horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and plate movements. It has 452 volcanoes (more than 75% of the world's active and dormant volcanoes).About 90% of the world's earthquakes and about 81% of the world's largest earthquakes occur along the Ring of Fire. All but three of the world's 25 largest volcanic eruptions of the last 11,700 years occurred at volcanoes in the Ring of Fire. The Ring of Fire is a direct result of plate tectonics: the movement and collisions of lithospheric plates, especially subduction in the northern portion. The western portion is more complex, with a number of smaller tectonic plates in collision with the Pacific plate from the Mariana Islands, the Philippines, Bougainville, Tonga, and New Zealand.

Ross Island

Ross Island is an island formed by four volcanoes in the Ross Sea near the continent of Antarctica, off the coast of Victoria Land in McMurdo Sound. Ross Island lies within the boundaries of Ross Dependency, an area of Antarctica claimed by New Zealand.

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