Credit: Alvaro Ybarra Zavala/Getty Images
Inside the Haiti quake
Some 230,000 Haitians died when a magnitude-7 earthquake struck just outside Port-au-Prince on the afternoon of January 12. Scientists from around the world scrambled to the scene (SN Online: 1/16/10) to assess which fault had ruptured and whether more people were at risk. Early ideas held that the quake had broken along the well-known Enriquillo-Plantain Garden fault, which divides the Caribbean and North American tectonic plates. But U.S. Geological Survey scientists found no evidence of a large surface rupture there, instead spotting corals west of Port-au-Prince that had been lifted by the quake. Researchers concluded that most of the movement had been along a previously unknown fault (SN Online: 8/11/10), now called the Léogâne. If that’s correct, the strain that has accumulated in the last few centuries on the Enriquillo-Plantain Garden fault has not been released, and seismic hazard in Haiti remains high. Because such a large quake occurred without much surface rupture, geologists may need to rethink how to identify past quakes in the rock record, one team suggests in a special issue of Nature Geoscience.
Knocked for a loop A magnitude-8.8 earthquake in Chile tilts Earth’s axis a few centimeters and shortens the day, models suggest (SN Online: 3/3/10).
Aussie rex Paleontologists digging in Australia unearth the first known fossils of a tyrannosaur from the Southern Hemisphere (SN Online: 3/25/10).
Desktop discovery Google Earth images reveal one of Earth’s freshest impact craters, a 45-meter-wide hole in southwestern Egypt whacked out by a meteorite just a few thousand years ago (SN: 8/14/10, p. 13).
Early landing Fossilized footprints in 395-million-year-old rocks offer the earliest evidence for four-limbed creatures and raise new questions about when and where land dwellers evolved (SN: 1/30/10, p. 9).
Accelerated cycling Rising global temperatures are driving up river runoff to the sea by some 540 cubic kilometers per year (SN Online: 10/5/10).
Early bird A 125-million-year-old humpbacked dino may have had feathered arms (illustration, left), pushing back the first appearance of feathers in the fossil record (SN: 10/9/10, p. 16).
Farming’s surprise yields Irrigation in the American Midwest could be substantially cooling the region in the summer (SN: 2/13/10, p. 15). In the African Sahel (above), the arrival of large-scale agriculture has caused dust emissions to skyrocket (SN: 7/31/10, p. 14).
Nonliving color Researchers are using fossilized pigment structures to give dinosaurs and ancient birds a colorful makeover. One team has reconstructed the plumage on the oldest known feathered dino (SN: 2/27/10, p. 9). And giant emperor penguin fossils reveal that the birds once wore ruddy brown getups rather than tuxedo coloration (SN Online: 9/30/10).
Icy hot The eruption of Eyjafjallajökull in Iceland has researchers monitoring activity at nearby Katla (SN Online: 4/15/10) and has focused attention on the dangers of ice-covered volcanoes (SN: 9/25/10, p. 16).
Warm in the water Ancient marine reptiles may have been warm-blooded, with some species 20 degrees Celsius warmer than the surrounding waters (SN Online: 6/10/10).