Earthquakes not only cause the ground to shake, they can literally cause sand to liquefy. To learn more about how sand particles assemble and shear under stress, researchers are exploring the properties of sand. Results of this work will improve our ability to predict when sand liquefaction is likely to occur during an earthquake.
When Sifrhippus sandae, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale. It weighed in at around 12 pounds—and it was destined to get much smaller over the ensuing millennia. The change was caused by the release of vast amounts of carbon into the atmosphere and oceans. Here, you see 1) the teeth of Sifrhippus at its larger and smaller sizes and 2) an artist’s reconstruction of a modern horse compared with Sifrhippus. Photos by Kristen Grace, UFL and Danielle Byerley, UFL, respectively
Researchers have detected geoneutrinos (subatomic particles) deep within the Earth’s interior. Their discovery confirms that radioactivity makes a significant contribution to the power produced within the Earth. The finding could help geologists understand how reactions taking place in the planet’s deep interior affect events on the surface such as earthquakes and volcanoes. Here, photomultipliers line the steel chamber of the Borexino neutrino detector. Credit: Virginia Tech, INFN
Not far off the coast of the northwestern U.S. in the Pacific Ocean lies Axial Volcano, one of the most active volcanoes on the Juan de Fuca Ridge. Researchers from Oregon State University and the Lamont Doherty Earth Observatory at Columbia University have been evaluating this “monster” with periodic underwater surveys.
Photo: Stunning bird’s eye view of hot lava. Credit: © 2010 Jupiterimages Corporation
