Search results
Results From The WOW.Com Content Network
A lithosphere (from Ancient Greek λίθος (líthos) 'rocky' and σφαίρα (sphaíra) 'sphere') is the rigid, [1] outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time scales of up to ...
Earth's inner core is the innermost geologic layer of the planet Earth. It is primarily a solid ball with a radius of about 1,220 km (760 mi), which is about 19% of Earth's radius [0.7% of volume] or 70% of the Moon 's radius. [ 32][ 33] The inner core was discovered in 1936 by Inge Lehmann and is generally composed primarily of iron and some ...
The lithosphere–asthenosphere boundary (referred to as the LAB by geophysicists) represents a mechanical difference between layers in Earth's inner structure. Earth's inner structure can be described both chemically ( crust, mantle, and core) and mechanically. The lithosphere–asthenosphere boundary lies between Earth's cooler, rigid ...
Plate tectonics (from Latin tectonicus, from Ancient Greek τεκτονικός (tektonikós) 'pertaining to building') [ 1] is the scientific theory that Earth 's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. [ 2][ 3][ 4] The model builds on the concept of continental ...
Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper part of the mantle. [1] The lithosphere is broken into tectonic plates whose motion allows heat to escape ...
Earth's mechanically rigid outer layer of Earth's crust and upper mantle, the lithosphere, is divided into tectonic plates. These plates are rigid segments that move relative to each other at one of three boundaries types: at convergent boundaries , two plates come together; at divergent boundaries , two plates are pulled apart; and at ...
Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around 100 km (62 mi) thick and consist of two principal types of material: oceanic crust (also called sima from silicon and magnesium ) and continental crust ( sial from silicon and aluminium ).
The asthenosphere shown at a subduction boundary. The asthenosphere (from Ancient Greek ἀσθενός (asthenós) 'without strength') is the mechanically weak [1] and ductile region of the upper mantle of Earth. It lies below the lithosphere, at a depth between ~80 and 200 km (50 and 120 mi) below the surface, and extends as deep as 700 km ...