Search results
Results from the WOW.Com Content Network
The sima layer is also called the 'basal crust' or 'basal layer' because it is the lowest layer of the crust. Because the ocean floors are mainly sima, it is also sometimes called the 'oceanic crust'. The name 'sima' was taken from the first two letters of silica and of magnesia. Comparable is the term sial (another antiquated blended term), [2 ...
Map showing Earth's principal tectonic plates and their boundaries in detail. These plates comprise the bulk of the continents and the Pacific Ocean.For purposes of this list, a major plate is any plate with an area greater than 20 million km 2 (7.7 million sq mi)
GEBCO is the only intergovernmental body with a mandate to map the whole ocean floor. At the beginning of the project, only 6 per cent of the world's ocean bottom had been surveyed to today's standards; as of June 2022, the project had recorded 23.4 per cent mapped. About 14,500,000 square kilometres (5,600,000 sq mi) of new bathymetric data ...
Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumulates. [1] [2] The crust overlies the rigid uppermost layer of the mantle.
The satellite will fly two radar antennas at either end of a 10 m (33 ft) mast, allowing it to measure the elevation of the surface across a 120 km (75 mi) wide swath. The new radar system is smaller than, but similar to, the one that flew on NASA's Shuttle Radar Topography Mission (SRTM), which made high-resolution measurements of Earth's land ...
Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. Oceanic trenches are prominent, long, narrow topographic depressions of the ocean floor. They are typically 50 to 100 kilometers (30 to 60 mi) wide and 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic ...
The Blue Marble is a photograph of Earth taken on December 7, 1972, by either Ron Evans or Harrison Schmitt aboard the Apollo 17 spacecraft on its way to the Moon.Viewed from around 29,400 km (18,300 mi) from Earth's surface, [1] a cropped and rotated version has become one of the most reproduced images in history.
Marine geology or geological oceanography is the study of the history and structure of the ocean floor. It involves geophysical, geochemical, sedimentological and paleontological investigations of the ocean floor and coastal zone. Marine geology has strong ties to geophysics and to physical oceanography.