Strong vibrations during large impacts make rocks to flow

Sixty-six million years ago, an asteroid, the size of a small city crashed into Earth. This impact left a crater several miles underground and more than 115 miles wide.


This crater is called Chicxulub, which lies underneath the Yucatán Peninsula of Mexico and happens to be the best-preserved large impact crater on Earth. When an asteroid crashes into Earth, which, if the asteroid is big enough, can be more than 20 miles deep, at which point it becomes unstable and collapses.


Researchers from the Department of earth, atmospheric and planetary sciences at Purdue University have now determined that really strong vibrations shaking the rock constantly enough, allow the latter to flow.



This mechanism, known as "acoustic fluidization," is the process that allows the ring of mountains in the crater's center to rise within minutes of the asteroid's strike. The International Ocean Discovery Program drilled a core roughly six inches in diameter and a mile into Earth, collecting rock that was shattered and partly melted by the impact that wiped out the dinosaurs.


In scrutinizing fracture zones and patterns in the core, the international research team found a progression in the vibration sequence that would allow debris to flow.


#Crater #Asteroids

 

©2018 by Mind Brunch