3-D Map Study Shows Before-After of 2010 Mexico Quake

Geologists have a new tool to study how earthquakes change the landscape, and it's giving them insight into how earthquake faults behave. In the Feb. 10 issue of the journal Science, a team of scientists from the United States, Mexico and China, including geophysicist Eric Fielding of NASA's Jet Propulsion Laboratory, Pasadena, Calif., reports the most comprehensive before-and-after picture yet of an earthquake zone, using data from the magnitude 7.2 event that struck near Mexicali, northern Mexico in April 2010.

"This study provides new information on how rocks in and around fault zones are deformed during earthquakes," said Fielding. "It helps scientists understand past events and assess the likelihood of future earthquakes in other complex systems of faults."

The team, working with the National Center for Airborne Laser Mapping, flew over the area with lidar (light detection and ranging), which bounces laser pulses off the ground and measures their reflection to determine the height of the surface. New airborne lidar equipment can measure features in the surface height to within a few inches. The researchers were able to make a detailed scan after the earthquake over about 140 square miles (363 square kilometers) in less than three days, said Michael Oskin, geology professor at the University of California, Davis. He is the lead author of the study, which was funded by the National Science Foundation, the U.S. Geological Survey, Consejo Nacional de Ciencia y Tecnología (Mexico) and NASA.

International Team to Drill Beneath Massive Antarctic Ice Shelf

An international team of researchers funded by NASA and the National Science Foundation (NSF) will travel next month to one of Antarctica's most active, remote and harsh spots to determine how changes in the waters circulating under an active ice sheet are causing a glacier to accelerate and drain into the sea.

The science expedition will be the most extensive ever deployed to Pine Island Glacier. It is the area of the ice-covered continent that concerns scientists most because of its potential to cause a rapid rise in sea level. Satellite measurements have shown this area is losing ice and surrounding glaciers are thinning, raising the possibility the ice could flow rapidly out to sea.

The multidisciplinary group of 13 scientists, led by Robert Bindschadler, emeritus glaciologist of NASA's Goddard Space Flight Center in Greenbelt, Md., will depart from the McMurdo Station in Antarctica in mid-December and spend six weeks on the ice shelf. During their stay, they will use a combination of traditional tools and sophisticated new oceanographic instruments to measure the shape of the cavity underneath the ice shelf and determine how streams of warm ocean water enter it, move toward the very bottom of the glacier and melt its underbelly.

NASA Continues Critical Survey of Antarctica's Changing Ice

Scientists with NASA's Operation IceBridge airborne research campaign began the mission's third year of surveys this week over the changing ice of Antarctica.Researchers are flying a suite of scientific instruments on two planes from a base of operations in Punta Arenas, Chile: a DC-8 operated by NASA and a Gulfstream V (G-V) operated by the National Science Foundation and the National Center for Atmospheric Research. The G-V will fly through early November. The DC-8, which completed its first science flight Oct. 12, will fly through mid-November.

Ninety-eight percent of Antarctica is covered in ice. Scientists are concerned about how quickly key features are thinning, such as Pine Island Glacier, which rests on bedrock below sea level. Better understanding this type of change is crucial to projecting impacts like sea-level rise.

"With a third year of data-gathering underway, we are starting to build our own record of change," said Michael Studinger, IceBridge project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "With IceBridge, our aim is to understand what the world's major ice sheets could contribute to sea-level rise. To understand that you have to record how ice sheets and glaciers are changing over time."

NASA Funded Study Shows Desert Dust Cuts Colorado River Flow

Snow melt in the Colorado River basin is occurring earlier, reducing runoff and the amount of crucial water available downstream. A new study shows this is due to increased dust caused by human activities in the region during the past 150 years. The study, led by a NASA scientist and funded by the agency and the National Science Foundation (NSF), showed peak spring runoff now comes three weeks earlier than before the region was settled and soils were disturbed. Annual runoff is lower by more than five percent on average compared to pre-settlement levels.

The findings have major implications for the 27 million people in the seven U.S. states and Mexico who rely on the Colorado River for drinking, agricultural and industrial water. The results were published in this week's Proceedings of the National Academy of Sciences. The research team was led by Tom Painter, a snow hydrologist at both NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the University of California at Los Angeles. The team examined the impact of human-produced dust deposits on mountain snowpacks over the Upper Colorado River basin between 1915 and 2003. Studies of lake sediment cores showed the amount of dust falling in the Rocky Mountains increased by 500 to 600 percent since the mid-to-late 1800s when grazing and agriculture began to disturb fragile but stable desert soils.

The team used an advanced hydrology model to simulate the balance of water flowing into and out of the river basin under current dusty conditions and those that existed before soil was disturbed. Hydrologic data gathered from field studies funded by NASA and NSF and measurements of the absorption of sunlight by dust in snow were combined with the modeling. More than 80 percent of sunlight falling on fresh snow is typically reflected back into space. In the semi-arid regions of the Colorado Plateau and Great Basin, winds blow desert dust east, triggering dust-on-snow events. When dark dust particles fall on snow, they reduce its ability to reflect sunlight. The snow also absorbs more of the sun's energy. This darker snow cover melts earlier, with some water evaporating into the atmosphere.