Great Meteor Seamount

The Great Meteor Seamount, also called the Great Meteor Tablemount, is a guyot and the largest seamount in the North Atlantic with a volume of 24,000 km3 (5,800 cu mi). It is one of the Seewarte Seamounts, rooted on a large terrace located south of the Azores Plateau. The crust underlying Great Meteor has an age of 85 million years, deduced from the magnetic anomaly 34 (An34) at this location.[2]

The shallow and flat summit of the Great Meteor Seamount, ranging between 150 and 300 m (490 and 980 ft) below sea level, suggests that it may have emerged sometime in the past.[3] It is covered by a 150 to 600 m (490 to 1,970 ft) thick layer of limestone, pyroclastic rocks and bioclastic sandstones.[4] Dredged basalts from the top of the eastern and southeastern flanks of the seamount have been K–Ar dated 10.7 ± 0.5 and 16.3 ± 0.4 million years old, respectively.[5] The oldest sample has been 40Ar/39Ar dated at 17 ± 0.3 million years old.[6]

Two small seamounts exist just southwest of Great Meteor and are encircled by the −3800 m bathymetric line. These are the Closs Seamount, roughly oriented NNE-SSW, with its peak at 1,400 m (4,600 ft) depth and covering an area of approximately 390 km2 (150 sq mi), and the Little Meteor Seamount, located NNE of Closs, with over 960 km2 (370 sq mi) and a flat top 400 m (1,300 ft) below sea level.

The German research vessel Meteor discovered the tablemount between 1925 and 1927. It was given the name Great Meteor Bank, a designation still used in the official GEBCO gazetteer.

Great Meteor Seamount
Greatmeteorseamount3d
Great Meteor Seamount at the southern edge of the Atlantis-Meteor Seamount Complex
Summit depth270 m (890 ft)
Height4,500 m (14,800 ft)
Summit area50x28 km² (1465 km²)[1]
Location
LocationNorth Atlantic Ocean, 1,000 km (620 mi) south of the Azores
Coordinates29°57′10.6″N 28°35′31.3″W / 29.952944°N 28.592028°WCoordinates: 29°57′10.6″N 28°35′31.3″W / 29.952944°N 28.592028°W
Geology
TypeGuyot
Volcanic arc/chainSeewarte Seamounts
History
Discovery date1938
Discovered byMeteor

Formation

The New England hotspot formed the White Mountains 124 to 100 million years ago when the North American continent was directly overhead. As the continent drifted to the west, the hotspot gradually moved offshore. On a southeasterly course, the hotspot formed Bear Seamount, the oldest in the chain, about 100 to 103 million years ago. Over the course of millions of years, it continued creating the rest of the seamounts, eventually culminating in the Nashville Seamount about 83 million years ago. As the Atlantic Ocean continued to spread, the hotspot eventually traveled further east, forming the Great Meteor Seamount where it is found today.[7] Radiometric dating of basalt from the Great Meteor Seamount has given ages of about 11 and 16 million years old, with the bulk of the seamount possibly having formed about 22 million years ago.[8]

Ecology

The unique ecological condition of the Great Meteor Seamount is shown by the many endemic copepod and nematode species.[1]

References

  1. ^ a b SPOTLIGHT 5 Great Meteor Seamount
  2. ^ Verhoef, Jaap (1984). "A Geophysical Study of the Atlantis-Meteor Seamount Complex". Geologica Ultraiectina. 38: 1–153. hdl:1874/238521. ISSN 0072-1026.
  3. ^ Gente, Pascal; Dyment, Jérôme; Maia, Marcia; Goslin, Jean (2003-10-01). "Interaction between the Mid-Atlantic Ridge and the Azores hot spot during the last 85 Myr: Emplacement and rifting of the hot spot-derived plateaus". Geochemistry, Geophysics, Geosystems. 4 (10): 8514. Bibcode:2003GGG.....4.8514G. doi:10.1029/2003gc000527. ISSN 1525-2027.
  4. ^ Ulrich, von Rad (1974-11-14). "Composition of bioclastic sands, carbonates and pyroclastic rocks of the Great Meteor and Josephine Seamounts, eastern North Atlantic". PANGAEA. doi:10.1594/pangaea.548422. Cite journal requires |journal= (help)
  5. ^ Wendt, I.; Kreuzer, H.; Müller, P.; Rad, U. von; Raschka, H. (1976). "K-Ar age of basalts from Great Meteor and Josephine seamounts (eastern North Atlantic)". Deep Sea Research and Oceanographic Abstracts. 23 (9): 849–862. Bibcode:1976DSROA..23..849W. doi:10.1016/0011-7471(76)90852-4.
  6. ^ Geldmacher, Jörg; Hoernle, Kaj; Klügel, Andreas; Bogaard, Paul v. d.; Wombacher, Frank; Berning, Björn (2006-09-01). "Origin and geochemical evolution of the Madeira-Tore Rise (eastern North Atlantic)". Journal of Geophysical Research: Solid Earth. 111 (B9): B09206. Bibcode:2006JGRB..111.9206G. doi:10.1029/2005jb003931. ISSN 2156-2202.
  7. ^ "Geological Origin of the New England Seamount Chain". Office of Ocean Exploration and Research, National Oceanic and Atmospheric Administration. U.S. Department of Commerce. 2005. Retrieved 14 April 2014.Revised August 25, 2010 by the Ocean Explorer
  8. ^ Hekinian, Roger; Stoffers, Peter; Cheminée, Jean-Louis (2012). Oceanic Hotspots: Intraplate Submarine Magmatism and Tectonism. Springer. p. 116. ISBN 978-3-642-62290-8.
Bear Seamount

The Bear Seamount is a guyot or flat-topped underwater volcano in the Atlantic Ocean. It is the oldest of the New England Seamounts, which was active more than 100 million years ago. It was formed when the North American Plate moved over the New England hotspot. It is located inside the Northeast Canyons and Seamounts Marine National Monument, which was proclaimed by President of the United States Barack Obama to protect the seamount's biodiversity.

Calliostoma heugteni

Calliostoma heugteni is a species of sea snail, a marine gastropod mollusk in the family Calliostomatidae.

German survey ship Meteor

Meteor was a German survey vessel, noted for her survey work in the Atlantic Ocean between 1925 and 1927. Handed over to the Soviet Union following World War II, the ship was renamed Ekvator. Her ultimate fate is not known.

Gnathophis codoniphorus

Gnathophis codoniphorus is an eel in the family Congridae (conger/garden eels). It was described by Günther Maul in 1972. It is a marine, deep water-dwelling eel which is known from the Azorean slope at the Great Meteor Seamount, in the northeastern Atlantic Ocean. It dwells at a depth range of 300–304 metres (984–997 ft).

Loricifera

Loricifera (from Latin, lorica, corselet (armour) + ferre, to bear) is a phylum of very small to microscopic marine cycloneuralian sediment-dwelling animals with 37 described species, in nine genera. Aside from these described species, there are approximately 100 more that have been collected and not yet described. Their sizes range from 100 µm to ca. 1 mm. They are characterised by a protective outer case called a lorica and their habitat, which is in the spaces between marine gravel to which they attach themselves. The phylum was discovered in 1983 by Reinhardt Kristensen, in Roscoff, France. They are among the most recently discovered groups of Metazoans. They attach themselves quite firmly to the substrate, and hence remained undiscovered for so long. The first specimen was collected in the 1970s, and later described in 1983. They are found at all depths, in different sediment types, and in all latitudes.

New England Seamounts

The New England Seamounts are an underwater chain of seamounts in the Atlantic Ocean stretching over 1,000 km from the edge of the Georges Bank off the coast of Massachusetts. The chain consists of over twenty extinct volcanic peaks, many rising over 4,000 m from the seabed. It is the longest seamount chain in the North Atlantic and harbours a diverse range of deep sea fauna. Scientists have visited the chain on various occasions to survey the geologic makeup and biota of the region. The chain forms part of the Great Meteor hotspot track, having formed by the movement of the North American Plate over the New England hotspot. The oldest volcanoes that were formed by the same hotspot are northwest of Hudson Bay, Canada. Part of the seamount chain is protected by Northeast Canyons and Seamounts Marine National Monument.

This seamount range has been known under a variety of different gazetted names, including the Kelvin Seamounts, Kelvin Seamount Group, Kelvin Banks, New England Seamount Chain and the Bermuda-New England Seamount Arc.

New England hotspot

The New England hotspot, also referred to as the Great Meteor hotspot, is a long-lived volcanic hotspot in the Atlantic Ocean. The hotspot's most recent eruptive center is the Great Meteor Seamount, and it probably created a short line of mid to late-Cenozoic age seamounts on the African Plate but appears to be currently inactive.The New England hotspot track is used to estimate the movement of the North American Plate away from the African Plate from early Cretaceous period to the present.The New England hotspot has been overridden by the Mid-Atlantic Ridge.

Outline of oceanography

The following outline is provided as an overview of and introduction to Oceanography.

Rissoina meteoris

Rissoina meteoris is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoinidae.

Schwartziella peregrina

Schwartziella peregrina is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Zebinidae.

Seewarte Seamounts

The Seewarte Seamounts, also known as the Atlantis-Great Meteor Seamount Chain and the Atlantis-Plato-Cruiser-Great Meteor Seamount Group, is a north-south trending group of extinct submarine volcanoes in the northern Atlantic Ocean south-southeast of the Corner Rise Seamounts.

The Seewarte Seamounts have been interpreted to have formed as a result of the African Plate traveling over the New England hotspot.

Sharpnose sevengill shark

The sharpnose sevengill shark (Heptranchias perlo), also known as one-finned shark, perlon shark, sevengill cow shark, sharpsnouted sevengill or slender sevengill, is a species of shark in the family Hexanchidae, and the only living species in the genus Heptranchias. Found almost circumglobally in deep water, it is one of the few species of sharks with seven pairs of gill slits as opposed to the usual five. The other shark species with seven gill slits is the broadnose sevengill shark. Though small, this shark is an active, voracious predator of invertebrates and fish. When caught, this species is notably aggressive and will attempt to bite. It is of minor commercial importance.

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