The Darwin Rise is broad triangular region in the north central Pacific Ocean where there is a concentration of

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can ...

s. During his voyage across the globe

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

realised that vertical crustal motion must be responsible for the formation of continents and ocean basins, as well as isolated atolls in the Pacific. He deduced that the central basin of the Pacific had subsided while surrounding areas had risen. In 1964 U.S. geologist Henry Menard subsequently named the uplifted area in the Pacific after the English naturalist.

Geological context

Covering an area of , the Darwin Rise is limited to the east by the Izu–Bonin and

Mariana Mariana may refer to: Literature * ''Mariana'' (Dickens novel), a 1940 novel by Monica Dickens * ''Mariana'' (poem), a poem by Alfred Tennyson, 1st Baron Tennyson * ''Mariana'' (Vaz novel), a 1997 novel by Katherine Vaz Music *"Mariana", a so ...

trenches, to the west by the

Line Islands The Line Islands, Teraina Islands or Equatorial Islands (in Gilbertese, ''Aono Raina'') are a chain of 11 atolls (with partly or fully enclosed lagoons) and coral islands (with a surrounding reef) in the central Pacific Ocean, south of the Haw ...

. Two major plateaux, the

Shatsky Rise The Shatsky Rise is Earth's third largest oceanic plateau, (after Ontong Java and Kerguelen) located in the north-west Pacific Ocean east of Japan. It is one of a series of Pacific Cretaceous large igneous provinces (LIPs) together with Hess ...

to the north and the

Ontong Java Plateau The Ontong Java Plateau (OJP) is a massive oceanic plateau located in the southwestern Pacific Ocean, north of the Solomon Islands. The OJP was formed around (Ma) with a much smaller volcanic event around 90 Ma. Two other southwestern Pacific ...

to the south, border the Darwin Rise. How these plateaux relate to the rise remains disputed. There are six major chains of seamounts on the rise — the

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

Magellan Ferdinand Magellan ( or ; pt, Fernão de Magalhães, ; es, link=no, Fernando de Magallanes, ; 4 February 1480 – 27 April 1521) was a Portuguese explorer. He is best known for having planned and led the 1519 Spanish expedition to the Eas ...

, Wake,

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Internati ...

seamounts and the

Mid-Pacific Mountains The Mid-Pacific Mountains (MPM) is a large oceanic plateau located in the central North Pacific Ocean or south of the Hawaiian–Emperor seamount chain. Of volcanic origin and Mesozoic in age, it is located on the oldest part of the Pacific Plat ...

— and numerous minor clusters. The ages of these seamounts in general follow the motion of the

Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and I ...

from 130 to 180 , as predicted by conventional hotspot theory, and decrease from west to east and north to south. This age-distance pattern is, however, not corroborated by the limited data available.

Origin

In 1964, Henry Menard proposed that this was a

superswell A superswell is a large area of anomalously high topography and shallow ocean regions. These areas of anomalous topography are byproducts of large upwelling of mantle material from the core–mantle boundary, referred to as superplumes. Two pres ...

raised by volcanism during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

(120-80 mya). A problem with this conjecture is that this region actually has a sea floor at a normal depth that happens to possess an abundance of

sea mount A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abru ...

s. Instead this feature may have formed from

diapir A diapir (; , ) is a type of igneous intrusion in which a more mobile and ductily deformable material is forced into brittle overlying rocks. Depending on the tectonic environment, diapirs can range from idealized mushroom-shaped Rayleigh– ...

s or plumes rising from the Earth's

upper mantle The upper mantle of Earth is a very thick layer of rock inside the planet, which begins just beneath the crust (at about under the oceans and about under the continents) and ends at the top of the lower mantle at . Temperatures range from appro ...

, which results in chains of sea mounts along the direction of the plate motion. However, this idea remains in dispute and an alternate hypothesis involving multiple "plumelets" has been proposed. In the 1980s it was proposed that the Darwin Rise was the South Pacific Superswell 100 Ma and that the volcanoes of the Darwin Rise erupted over the same mantle region as the volcanoes of French Polynesia today. Hence, U.S. geologist

Marcia McNutt Marcia Kemper McNutt (born February 19, 1952) is an American geophysicist and the 22nd president of the National Academy of Sciences (NAS) of the United States. Previously, she served as editor-in-chief of the peer-reviewed journal ''Science'' fro ...

Geological context

Origin

See also

References

Notes

Sources