Search results
Results From The WOW.Com Content Network
The early Earth was entirely molten. This was due to high temperatures created and maintained by the following processes: Compression of the early atmosphere; Rapid axial rotation; Regular impacts with neighbouring planetesimals. [2] A phase diagram showing sequential crystallisation within the early mantle, forming the early crust.
English: How crater-depth is measured, using the side-view of a typical crater. Depth "A" measures from the surface to the bottom of the crater. Depth "B" measures from the mean height of the rim to the bottom of the crater.
Further research identified the giant Chicxulub crater, buried under Chicxulub on the coast of Yucatán, as the source of the K–Pg boundary clay. Identified in 1990 [14] based on work by geophysicist Glen Penfield in 1978, the crater is oval, with an average diameter of roughly 180 km (110 mi), about the size calculated by the Alvarez team.
The Chicxulub crater is an impact crater buried underneath the Yucatán Peninsula in Mexico. [10] Its center is located near the town of Chicxulub, after which the crater is named. [11] It was formed by a large asteroid or comet about 10–15 km (6.2–9.3 mi) in diameter, [12] [13] the Chicxulub impactor, striking the Earth. The date of the ...
A volcanic crater is a bowl-shaped depression in the ground caused by volcanic activity, usually located above the volcano's vent. [11] During volcanic eruptions, molten magma and volcanic gases rise from an underground magma chamber, through a conduit, until they reach the crater's vent, from where the gases escape into the atmosphere and the magma is erupted as lava.
Luis Walter Alvarez, left, and his son Walter, right, at the K–T Boundary in Gubbio, Italy, 1981. The Alvarez hypothesis posits that the mass extinction of the non-avian dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth.
For example, it is only 28% the size of Earth's Moon and 41% that of Pluto, another dwarf planet. It is comparable in size to Saturn's moons Tethys and Dione . Ceres' small size means that it cooled much faster than full-sized planets and larger moons, limiting its degree of thermal evolution.
Mosaic evolution – Evolution of characters at various rates both within and between species; Parallel evolution – Similar evolution in distinct species; Quantum evolution – Evolution where transitional forms are particularly unstable and do not last long; Recurrent evolution – The repeated evolution of a particular character