arctic ocean ridge

The significance of plagioclase textures in mid …

The Gakkel Ridge, located within the Arctic Ocean, is the ultraslow-spreading end member in the global mid-ocean ridge system (Fig. 1); the spreading rate decreases from 14.6 to 6.3 mm year −1 from …

GEOCHEMISTRY Copyright © 2020 An Early Cretaceous …

the Western Gakkel Ridge region in the Arctic Ocean through MORB geochemistry and tectonic plate reconstruc-tion. We find that seafloor lavas from the Western Gakkel Ridge region mirror geochemical signatures of an Early Cretaceous, paleo-subduction zone, and conclude that the upper mantle can preserve a long-lived, stationary

Dive and Discover : Expedition 11 : The Gakkel Ridge : Home

The Gakkel Ridge It wasn't until 2001, on the maiden voyage of the U.S. Coast Guard icebreaker Healy, that scientists first detected tantalizing clues that the Arctic seafloor may be unlike the seafloors of the more-explored Atlantic and Pacific Oceans.. The Gakkel Ridge is the deepest mid-ocean ridge, ranging from 3 to 5 kilometers (1.8 to 3 …

Oceanic ridge | Description, Examples, & Facts | Britannica

Oceanic ridge, any of several submarine mountain chains rising from the ocean floor. Individually, the ridges are the largest features in ocean basins. Collectively, they form the worldwide oceanic ridge system—at about 80,000 km (50,000 miles) long, Earth's largest surface feature after continents and ocean basins.

Morphology and structure of the Lomonosov Ridge, Arctic Ocean

The Lomonosov Ridge is a band of continental crust that stretches across the Arctic Ocean and separates the Mesozoic Amerasian Basin from the Cenozoic Eurasian Basin. From about 87°N north of Greenland across the Pole to about 86°N, the Lomonosov Ridge is a single highstanding blocky ridge with minimum depths of …

Ancient, highly heterogeneous mantle beneath Gakkel ridge, Arctic Ocean

Here we show that some refractory abyssal peridotites from the ultraslow-spreading Gakkel ridge (Arctic Ocean) have very depleted 187Os/188Os ratios with model ages up to 2 billion years, implying the long-term preservation of refractory domains in the asthenospheric mantle rather than their erasure by mantle convection. The refractory …

Threshold in North Atlantic-Arctic Ocean circulation

Therein, the subsidence of the Greenland–Scotland Ridge (GSR) from subaerial conditions towards a submarine rise constitutes an active ocean gateway control of North Atlantic-Arctic water ...

Arctic Ocean

The following are examples of mid-ocean ridges found on the floor of the Arctic Ocean (see Figure 2). Gakkel Ridge Mohns Ridge seamounts: Seamounts (see Figure 1) are submarine mountains at least 1,000 m (3,300 ft) high formed from individual volcanoes on the ocean floor.

Glacial-interglacial sedimentation and paleocirculation at the

Sediment core HLY0503-03JPC from the top of the Northwind Ridge provides the first confirmed Plio-Pleistocene record from the western Arctic Ocean, with calcareous microfossils uniquely preserved ...

An improved bathymetric portrayal of the Arctic Ocean: …

The ridge's bathymetry has long been discussed among oceanographers, given its impact on the circulation and water mass properties of the Arctic Ocean [e.g., Aagaard, 1981]. In the Amerasian Basin, the deep bottom waters close to the Lomonosov Ridge have been found to be slightly colder and less saline than the corresponding …

A. H. A. E. s. R. II.,J.

The Arctic Mid-Oceanic Ridge THE Mid-Oceanic Ridge, a broad fractured arch more than 40,000 miles long, is the largest tectonic feature on the surface of the Earth. ... Ocean Congress, 1. 26 (1959).

Magmatic and amagmatic seafloor generation at the …

Gakkel ridge stretches 1,800 km across the Eurasian basin of the Arctic Ocean ().To the west the plate boundary passes via the Lena trough and the Molloy fracture zone into the Knipovich ridge.

The fiery face of the Arctic deep | Max-Planck-Gesellschaft

The Gakkel ridge is a gigantic volcanic mountain chain stretching beneath the Arctic Ocean. With its deep valleys 5,500 meter beneath the sea surface and its 5,000 meter high summits, Gakkel ridge is far mightier than the Alps. This is the site of seafloor spreading that is actively separating Europe from North America, and was the goal of the ...

The Arctic Ocean—facts and information

March 29, 2019. • 7 min read. The Arctic Ocean is Earth's northernmost body of water. It encircles the Arctic, and flows beneath it. Most of the Arctic Ocean is covered by ice …

Seismicity of the Arctic mid-ocean Ridge system | Request …

The active mid-ocean ridge of the Arctic Ocean, named Gakkel ridge, is the slowest spreading ridge of the global system of mid-oceanic ridges with full spreading rates declining from about 12.5 to ...

Diatom composition and fluxes over the Northwind Ridge, western Arctic

Our sampling site, Station DM, is located at the southern Northwind Ridge, a steep ledge extending from the shallow Chukchi Shelf into the Arctic deep basin as a part of the Chukchi Borderland (Fig. 1).The surface hydrology of the region is influenced by the dynamic Beaufort Gyre (BG) circulation, the PWI entering the Arctic Ocean through the …

The Arctic: Location & Geography

The Nansen-Gakkel Ridge (Arctic Mid-Ocean Ridge), an active seafloor spreading center stretches across the basin north of western Russia. The Pole Abyssal Plain, an elongated trough of deep water, lies between the Arctic Ridge and the basin's dominant feature, the Lomonosov Ridge—a mountain chain that averages 10,000 feet high above the ...

Arctic Ocean | Definition, Location, Map, Climate, & Facts

Arctic Ocean. Arctic Ocean, smallest of the world's oceans, centring approximately on the North Pole. The Arctic Ocean and its marginal seas—the Chukchi, East Siberian, Laptev, Kara, Barents, White, Greenland, and Beaufort and, according to some oceanographers, also the Bering and Norwegian —are the least-known basins and …

The Cenozoic palaeoenvironment of the Arctic Ocean | Nature

Sediments atop the ridge record the palaeoenvironmental evolution of the Cenozoic Arctic Ocean. Colours are water depth; dark blue is ∼ 4,000 m and the water depth over the ridge (light blue ...

An ultraslow-spreading class of ocean ridge | Nature

New investigations of the Southwest Indian and Arctic ridges reveal an ultraslow-spreading class of ocean ridge that is …

Volcanically hosted venting with indications of ultramafic

The Gakkel Ridge, which spans the ice-covered Arctic Ocean, is both the slowest-spreading mid-ocean ridge (0.7–1.4 cm/yr 3,4,5) and the least accessible because of year-round ice-cover.

The rush to claim an undersea mountain range

The quest to map the ocean floor; The ridge was first ... Even with modern ships passing powerful 864-beam arrays of sonar down through the Arctic waters, the resolution of the ridge is only in ...

Nations Claim Large Overlapping Sections of Arctic Seafloor

Russia could have outlined extended continental shelf along the Lomonosov Ridge across the center of the Arctic Ocean, all the way to Canada's 200-nautical-mile EEZ, but in its submission to the ...

Arctic Ocean | Definition, Location, Map, Climate,

Although the Arctic Ocean is by far the smallest of Earth's oceans, having only a little more than one-sixth the area of the next largest, the Indian Ocean, its area of 5,440,000 square miles (14,090,000 square …

Oceanic ridge | Description, Examples, & Facts

oceanic ridge, any of several continuous submarine mountain chains rising from the ocean floor. Individually, oceanic ridges are the largest features in ocean basins.

Location and source mechanism of sound signals at Gakkel ridge, Arctic …

The Arctic Mid-Ocean Ridge expedition in 2001 detected a hydrothermal event plume and explosive seismoacoustic signals. In 2007, the Arctic Gakkel Vents Expedition found direct evidence for recent submarine explosive activity on the seafloor at ∼4000 m. The newest data motivated a reassessment of the seismoacoustic events of …

Correlating microbial community profiles with geochemical data

We investigated the link between geochemistry and microbial communities in two 3-m-long sediment cores from the ultraslow-spreading Arctic Mid-Ocean Ridge system. The cores were retrieved 15 km southwest and 15 km northeast of the active hydrothermal field Loki's Castle (Fig. P1A) . The site is one of only a few localities where …

Arctic Ocean

The smallest of the Arctic Ocean subbasins, called the Nansen Basin, lies between the Nansen-Gakkel Ridge and the Eurasian continental margin and has a floor depth of 13,800 feet. The Amerasia Basin is divided into two unequal basins by the Alpha Cordillera (Alpha Ridge), a broad, rugged submarine mountain chain that extends to within 4,600 ...

Ancient, highly heterogeneous mantle beneath …

Here we show that some refractory abyssal peridotites from the ultraslow-spreading Gakkel ridge (Arctic Ocean) have very depleted 187 Os/ 188 Os ratios with …

Ancient, highly heterogeneous mantle beneath Gakkel ridge, Arctic Ocean …

Here we show that some refractory abyssal peridotites from the ultraslow-spreading Gakkel ridge (Arctic Ocean) have very depleted 187 Os/ 188 Os ratios with model ages up to 2 billion years, implying the long-term preservation of refractory domains in the asthenospheric mantle rather than their erasure by mantle convection. The refractory ...