Oceanic crust is the uppermost layer of the oceanic portion of a tectonic plate. The crust overlies the solidified and uppermost layer of the mantle. The crust and the solid mantle layer together comprise oceanic lithosphere.
Oceanic crust is the result of erupted mantle material originating from below the plate, cooled and in most instances, modified chemically by seawater. This occurs mostly at mid-ocean ridges, but also at scattered hotspots, and also in rare but powerful occurrences known as flood basalt eruptions. It is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium. It is thinner than continental crust, or sial, generally less than 10 kilometers thick; however it is denser, having a mean density of about 2.9 grams per cubic centimeter as opposed to continental crust which has a density of about 2.7 grams per cubic centimeter.
Although a complete section of oceanic crust has not yet been drilled, geologists have several pieces of evidence that help them understand the ocean floor. Estimations of composition are based on analyses of ophiolites (sections of oceanic crust that are preserved on the continents), comparisons of the seismic structure of the oceanic crust with laboratory determinations of seismic velocities in known rock types, and samples recovered from the ocean floor by submersibles, dredging (especially from ridge crests and fracture zones) and drilling. Oceanic crust is significantly simpler than continental crust and generally can be divided in three layers.
By Puja Gupta. New Delhi, April 11 (IANSlife) Hard Rock Cafe has always been popular among music lovers for its Rock 'n' Roll theme and outstanding in-house gigs. Bringing forth the idea of 'good food and good music', it has launched a new menu ...The new menu brings to one's plate the amalgamation of two different gastronomic cultures across the ocean.
Are positioned within the 10,000 long Mid-Atlantic OceanRift...Iceland is one of the most geologically active islands on Earth because it lies along with one of the major fault breaks in Earth’s outer crust, the giant 10,000 miles long Mid-Atlantic Ocean Rift System ... In technical geological terms, the Mid-Atlantic Rift is a divergent plate boundary.
Taiwan is an island of extremes. severe earthquakes and typhoons repeatedly strike the region and change the landscape, sometimes catastrophically. This makes Taiwan a fantastic laboratory for geosciences ... The surprising result ... Taiwan is located at a subduction zone, where an ocean plate slides under the Asian continent ... Explore further ... DOI ... Citation.
the era when plate tectonics began ... They eventually showed that these plates—15 main ones and dozens of smaller ones—spread apart at mid-ocean ridges, move with the mantle’s flow, scrape against each other at their edges, and plunge back into the mantle at “subduction zones.” ... Most of that silicate-carbon dioxide reacting made by colliding plates.
Heinz Homestyle Gravy and OceanSpray Cranberries are running a Twitter poll to find out if consumers would support their idea for a new product ... blend of two foods that have shared the dinner plate for decades so they are teaming up to make Cravy a jarred, delicious reality.
April has always been my favorite month and not just because it is my birthday month!. It is also because it is National Poetry Month... It is whatever the writer wants it to be ... April 4, 1968.” ... It also includes teachable science information at the end to encourage young readers to learn more about things from tectonic plates to why the ocean has tides.
The continents, mountains, oceans, etc., always have been and always will be the same ... But why then were rocks and fossils of the same type found on continents an ocean apart? In 1912, the German meteorologist Alfred Wegener proposed at a meeting of Frankfurt’s Geological Associations that the Earth’s land masses were on the move.
"For all the self-congratulatory PR she was doing on her own behalf, Ivanka may as well have been shoving $5 bills into Coke bottles throwing them into the ocean, shouting 'help a woman!' after them as they crashed into the surf, before rushing off to a $1,000-a-plate 'female ...
For all the self-congratulatory PR she was doing on her own behalf, Ivanka may as well have been shoving $5 bills into Coke bottles throwing them into the ocean, shouting help a woman! after them as they crashed into the surf, before rushing off to a $1,000-a-plate female empowerment gala to give a speech about how much empowering she just did.
For all the self-congratulatory PR she was doing on her own behalf, Ivanka may as well have been shoving $5 bills into Coke bottles throwing them into the ocean, shouting “help a woman!” after them as they crashed into the surf, before rushing off to a $1,000-a-plate “female empowerment” gala to give a speech about how much empowering she just did.
In subduction zones, rocky plates at the bottom of the ocean chill and become increasingly dense until they're forced under the continents and back into the mantle below, taking ocean water with them ...Earth today loses heat through plate tectonics, when the ridged lithospheric plates that form the planet's solid, outer shell move around.
... mantle, when water penetrates cracks in the ocean floor—can carry surface water as far as 700 kilometers deep by plate tectonic processes ... Instead, it points to magnetite and other iron-rich minerals formed when oceanic plate peridotite transformed to serpentinite on the seafloor.
A vast global ocean may have covered early Earth during the early Archean eon, 4 to 3.2 billion years ago, a side effect of having a hotter mantle than today, according to new research ... Over geologic time, water can move from the surface ocean to the interior through plate tectonics, but the size of that water flux is not well understood.