Search results
Results from the WOW.Com Content Network
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. Prior to 2013, it was commonly cited as having happened about 65 million years ago, but Renne and colleagues (2013) gave an ...
Chicxulub crater. Chicxulub crater (Mexico) Free-air gravity anomaly over the Chicxulub structure (coastline and state boundaries shown as black lines) The Chicxulub crater (IPA: [t͡ʃikʃuˈluɓ] ⓘ cheek-shoo-LOOB) is an impact crater buried underneath the Yucatán Peninsula in Mexico. Its center is offshore, but the crater is named after ...
The Cretaceous–Paleogene (K–Pg) extinction event, [ a ] also known as the K–T extinction, [ b ] was the mass extinction of three-quarters of the plant and animal species on Earth [ 2 ][ 3 ] approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than 25 kilograms ...
Luis (left) and his son Walter Alvarez (right) at the K-Pg Boundary in Gubbio, Italy, 1981. In 1980, a team of researchers led by Nobel prize-winning physicist Luis Alvarez, his son, geologist Walter Alvarez, and chemists Frank Asaro and Helen Vaughn Michel discovered that sedimentary layers found all over the world at the Cretaceous–Paleogene boundary contain a concentration of iridium ...
Alvarez and others reported spikes in the level of platinum group metals like iridium at the Cretaceous–Tertiary boundary in Italy, Denmark, and New Zealand. They interpreted this sudden introduction of rare-earth metals as evidence for an asteroid impact, to which they attributed the mass extinction at the end of the Cretaceous Period. [39]
3581 Alvarez, provisional designation 1985 HC, is a carbonaceous asteroid and a very large Mars-crosser on an eccentric orbit from the asteroid belt, approximately 13.7 kilometers (8.5 miles) in diameter. It was discovered on 23 April 1985, by American astronomer couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California. [1]
Walter Alvarez (born October 3, 1940) is a professor in the Earth and Planetary Science department at the University of California, Berkeley. He and his father, Nobel Prize –winning physicist Luis Alvarez , developed the theory that dinosaurs were killed by an asteroid impact.
Frank Asaro (born Francesco Asaro, July 31, 1927 – June 10, 2014) was an Emeritus Senior Scientist at the Lawrence Berkeley National Laboratory associated with the University of California at Berkeley. [1] He is best known as the chemist who discovered the iridium anomaly in the Cretaceous–Paleogene boundary layer that led the team of Luis ...