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jesse davenport

Africa's impact is one that even the dinosaurs would have seen coming

The crater left by the infamous Chicxulub asteroid responsible for finishing off the dinosaurs about 65 million years ago, was more than 19 kilometers deep and 177 kilometers in diameter. Those dimensions correspond to a huge energy release estimated at 100 teratons of TNT, but that’s puny compared to an impact that struck South Africa’s Barberton Greenstone Belt about 3.26 billion years ago. Now, researchers have estimated just how big that massive asteroid was and the catastrophic effect it might have had on Earth and its budding plate tectonic system.

14 Aug 2014

Resolving a misplaced source of volcanism in the Galapagos

Geological models have long suggested the mantle plume that built the Galápagos islands lies below Fernandina Island. Using a novel combination of seismic techniques, however, scientists have found a mantle anomaly that appears to be the Galápagos plume located 150 kilometers southeast of Fernandina Island. The new findings better explain the ongoing volcanic activity and also shed light on interactions between the mantle and crust, researchers say.

07 Apr 2014

GPS measurements of ground inflation help forecast ash plumes

When Grimsvötn Volcano in Iceland erupted in May 2011, northern European airspace was closed for seven days and about 900 passenger flights were canceled. Scientists were charged with trying to read the volcano — to tell how high the ash plume would go and to figure out how long the violent eruption would last. Such features are hard to predict, but in a novel study, one research team has found a correlation between the height and composition of the Grimsvötn ash plume and ground deformation before and during the eruption. The findings, the team says, could improve volcanic plume dispersion models, which in turn could help air traffic managers determine when and where it’s safe to fly when volcanoes like Grimsvötn and Eyjafjallajökull suddenly erupt.

20 Feb 2014