Hawaiian-Emperor seamount chain

Information about Hawaiian-Emperor seamount chain

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Elevation of the Pacific seafloor, showing a long trail of underwater mountains stretching northwest from the Hawaiian islands


The Hawaiian-Emperor seamount chain is composed of the Hawaiian Ridge, consisting of the islands of the Hawaiian chain northwest to Kure Atoll, and the Emperor Seamounts, a vast underwater mountain region of islands and intervening seamounts, atolls, shallows, banks and reefs along a line trending southeast to northwest beneath the northern Pacific Ocean. The seamount chain, containing over 80 identified undersea volcanoes, stretches over 3,600 miles from the Aleutian Trench in the far northwest Pacific to Lo‘ihi seamount, the youngest volcano in the chain, which lies about 35 km southeast of the Island of Hawai‘i. The Hawaiian Islands are that portion of the Hawaiian-Emperor seamount chain that projects above sea level.

In 1963, geologist John Tuzo Wilson hypothesized the origins of the Hawaiian-Emperor seamount chain explaining that they were created by a hotspot of volcanic activity that was essentially stationary as the Pacific tectonic plate drifted in a northwesterly direction, leaving a trail of increasingly eroded volcanic islands and seamounts in its wake. An otherwise inexplicable kink in the chain would mark a shift in the movement of the Pacific plate some 47 million years ago, from a northward to a more northwesterly direction, and the kink has been presented in geology texts as an example of how a tectonic plate can shift direction comparatively suddenly. A look at the USGS map on the Origin of the Hawaiian Islands clearly shows this "spearpoint". Recent research shows that the hot spot itself may be moving southward (Tarduno et al., 2003). More recent studies, mentioned below, provide evidence that the change in direction may have occurred over a period of about 8 million years.

Recent analysis of the magnetization orientation of cooling magnetite in ancient lava flows taken at four seamounts shows a more complex relationship than the textbook stationary hotspot offered. If the hot spot had remained above a fixed mantle plume during the past 80 million years, the latitude as determined by the orientation of the magnetite should be constant for each sample and should also signify original cooling at the same latitude as the current Big Island of Hawaii.

Yet more recently published argon-argon ages of rocks from volcanoes of the southern and central Emperor chain better establish the age at which the bend formed. Sharp and Clague (2006) determined that the bend initiated at about 50 million years ago, and the bending continued until about 42 million years ago. They also concluded that the bend formed because of the "traditional" reason -- a change in the direction of motion of the Pacific plate.

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Coordinates:
State of Hawaii
Mokuʻāina o Hawaiʻi

Flag of Hawaii Seal of Hawaii
Nickname(s): The Aloha State

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Kure Atoll or Ocean Island (Hawaiian: Kānemiloha‘i) lies some 55 miles beyond Midway Atoll in the Northwestern Hawaiian Islands at . The International Date Line lies approximately 100 miles to the west.
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A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface (sea level), and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of 1,000 - 4,000 meters
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atoll is an island of coral that encircles a lagoon partially or completely.

Usage

Beau Briggs, the foremost atoll expert, says that the word atoll comes from the Dhivehi (an Indo-Aryan language spoken on the Maldive Islands) word atholhu
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Earth's oceans
(World Ocean)
  • Arctic Ocean
  • Atlantic Ocean
  • Indian Ocean
  • Pacific Ocean
  • Southern Ocean


The Pacific Ocean (from the Latin name Mare Pacificum
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The Aleutian Trench is an oceanic trench in the Earth's crust. It is classified as a marginal trench in the east but is termed an island arc west of Alaska. The trench extends for 3,400 km from the northern end of the Kuril-Kamchatka Trench to the Gulf of Alaska, marking
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Lōʻihi is a seamount and undersea volcano in the Hawaiian archipelago, located at 18.92° N, 155.27° W — roughly 30 km (19 mi) south of the southeast coast of the Island of Hawai
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Hawaiʻi
The Big Island<nowiki />

November 1985 satellite photo

Geography

Location in the state of Hawaii <nowiki/>
Location
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Hawaiian Islands, once known as the Sandwich Islands, form an archipelago of nineteen islands and atolls, numerous smaller islets, and undersea seamounts trending northwest by southeast in the North Pacific Ocean between latitudes 19° N and 29° N.
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19th century - 20th century - 21st century
1930s  1940s  1950s  - 1960s -  1970s  1980s  1990s
1960 1961 1962 - 1963 - 1964 1965 1966

Year 1963 (MCMLXIII
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John Tuzo Wilson

John Tuzo Wilson Medal of Geophysics
Born 24 September 1908(1908--)
Ottawa, Ontario Canada
Died 15 March 1993
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hotspot is a location on the Earth's surface that has experienced active volcanism for a long period of time. J. Tuzo Wilson came up with the idea in 1963 that volcanic chains like the Hawaiian Islands result from the slow movement of a tectonic plate across a "fixed" hot spot
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Pacific Plate is an oceanic tectonic plate beneath the Pacific Ocean.

To the north the easterly side is a divergent boundary with the Explorer Plate, the Juan de Fuca Plate and the Gorda Plate forming respectively the Explorer Ridge, the Juan de Fuca Ridge and the Gorda
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Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron(II,III) oxide and the common chemical name ferrous-ferric oxide.
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mantle plume is an upwelling of abnormally hot rock within the Earth's mantle. As the heads of mantle plumes can partly melt when they reach shallow depths, they are thought to be the cause of volcanic centers known as hotspots and probably also to have caused flood basalts.
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Argon-argon (or 40Ar/39Ar) dating is a radiometric dating technique similar to potassium-argon (K-Ar) dating. In this technique, the decay of 40K to 40
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Meiji Seamount is the oldest seamount in the Hawaiian-Emperor seamount chain, with an estimated age of 82 million years. It lies at the northernmost end of the chain, and is perched at the outer slope of the Kuril-Kamchatka Trench.
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New England Seamount chain is an underwater chain of seamounts in the Atlantic Ocean stretching over 1,000 kilometers from the edge of the Georges Bank off the coast of Massachusetts southeast to the Bermuda Rise.
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Kodiak-Bowie Seamount chain is a seamount chain in southeastern Gulf of Alaska stretching from the Aleutian Trench in the north to Bowie Seamount, the youngest volcano in the chain, which lies 180 kilometers west of the Queen Charlotte Islands, British Columbia.
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Most of the Hawaiian volcanoes (that is, the volcanoes that make up the Hawaiian Islands) go through several defined stages of evolution during their lifespans. These stages of growth are influenced by the position of the volcano in relation to the hotspot, whether the
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Plate tectonics (from Greek τέκτων, tektōn "builder" or "mason") is a theory of geology that has been developed to explain the observed evidence for large scale motions of the Earth's lithosphere.
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Isostasy is a term used in Geology to refer to the state of gravitational equilibrium between the Earth's lithosphere and asthenosphere such that the tectonic plates "float" at an elevation which depends on their thickness and density.
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oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor.

Trenches define one of the most important natural boundaries on the Earth’s solid surface, that between two lithospheric
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geographic coordinate system enables every location on the earth to be specified by the three coordinates of a spherical coordinate system aligned with the spin axis of the Earth.
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