Geology

A previously unknown, large impact basin has been discovered by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft during its second flyby of Mercury in October 2008. The impact basin, now named Rembrandt, more than 700 kilometers (430 miles) in diameter. If the Rembrandt basin had formed on the east coast of the United States, it would span the distance between Washington, D.C., and Boston. Large impact basins are important landforms created by the collision of asteroid-scale objects early in planetary history. The Rembrandt basin formed about 3.9…

The theory that the Chicxulub crater holds the clue to the demise of the dinosaurs and 40 percent of all species 65 million years ago is challenged in a paper published in the Journal of the Geological Society.  The Chicxulub crater, discovered in 1978 in northern Yucutan and measuring about 112 miles in diameter, lies under a km of debris and records a massive extra-terrestrial impact by an object 10-20 km in size. When spherules from the impact were found just below the Cretaceous-Tertiary (K-T) boundary, it was quickly identified as the "smoking gun" responsible for the mass…

A cool morning breeze keeps the mosquitoes down as we pack our kayaks and gear for today’s paddling journey.  It is day four of our holiday, with two days driving up from Vancouver to Cache Creek, past the Eocene insect and plant site at McAbee, the well-bedded Permian limestone near Marble Canyon and onto Bowron Provincial Park, a geologic gem near the gold rush town of Barkerville. The initial draw for me, given that collecting anything in a provincial park, especially fossils, is forbidden and all paleontological collecting close at hand outside the park appears to amount to a…

In the 1960s and early 1970s, the Apollo Moon Program struggled with a formidable enemy that was sometimes more formidable than others: sticky lunar dust. Four decades later, a new study says they now know why; forces that compel lunar dust to cling to surfaces change during the lunar day - with the elevation of the sun. The study analyzes the interactions on the Moon among electrostatic adhesive forces, the angle of incidence of the sun's rays, and lunar gravity. It concludes that the stickiness of lunar dust on a vertical surface changes as the sun moves higher in the sky, eventually…

Grizzly! We reach the end of Babcock Lake, the sixth body we will cross in completing the Bowron Lake circuit, we get prepared for our next portage. After packing up, I get my camera out to take advantage of the angle of the sun and the eroded rounded hilltops of the Quesnel Highlands that stand as backdrop. Leanne remarks that she can see a moose a little ways off and that it appeared to be heading our way.  Yes, heading our way quickly with a baby moose in tow.  I lift my lens to immortalize the moment and we three realize the moose are heading our way in double time because…

Propagation of earthquake waves within the Earth is not uniform. Experiments indicate that the velocity of shear waves (s-waves) in Earth's lower mantle between 660 and 2900 km depth is strongly dependent on the orientation of ferropericlase. In the latest issue of "Science" (Vol. 325, 10.04.2009), researchers from the German Research Center for Geosciences GFZ, the Karlsruhe Institute of Technology, the University of Bayreuth, and Arizona State University report unexpected properties of ferropericlase, which is presumably the second most abundant mineral of the lower mantle. "The…

VIRGINIA KEY, Fla. – A magnitude 8.0. earthquake destroyed 90 percent of the city of Pisco, Peru on August 16, 2007. The event killed 595 people, while another 318 were missing. Tsunami waves were observed locally, off the shore of Chile, and as far away as New Zealand. In a study published in the Geophysical Journal International, scientists from the University of Miami's Rosenstiel School of Marine and Atmospheric Science, in collaboration with scientists from the University of Oxford (U.K.) have analyzed data on this earthquake and its impact on regional topography. Using InSAR-based…

A magnitude 8.0. earthquake destroyed 90 percent of the city of Pisco, Peru on August 16, 2007. The event killed 595 people, while another 318 were missing. Tsunami waves were observed locally, off the shore of Chile, and as far away as New Zealand.  In a study published in the Geophysical Journal International, scientists from the University of Miami's Rosenstiel School of Marine and Atmospheric Science, in collaboration with scientists from the University of Oxford (U.K.) have analyzed data on this earthquake and its impact on regional topography. Using InSAR-based geodetic data and…

Saturn's largest moon, Titan, may have a subterranean ocean of hydrocarbons and some topsy-turvy topography in which the summits of its mountains lie lower than its average surface elevation, according to new research.  Titan is also more squashed in its overall shape—like a rubber ball pressed down by a foot—than researchers had expected, said Howard Zebker, a Stanford geophysicist and electrical engineer involved in the work. The new findings may help explain the presence of large lakes of hydrocarbons at both of Titan's poles, which have been puzzling researchers since being…

Just before dawn on Oct. 7, 2008, an SUV-sized asteroid entered Earth's atmosphere and exploded harmlessly over the Nubian Desert of northern Sudan. Scientists expected the asteroid, called 2008 TC3, had blown to dust in the resulting high-altitude fireball.  What happened next excited the scientific community.  Peter Jenniskens, a meteor astronomer with the SETI Institute in Mountain View, Calif., who works at NASA's Ames Research Center in Moffett Field, Calif., joined Muawia Shaddad of the University of Khartoum in Sudan to search for possible extraterrestrial remnants from the…