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19 December 2014
Scientists have used satellites to more accurately measure the slow creep of land along the Calaveras and Hayward faults east of the San Francisco Bay, a finding that helped the researchers estimate the magnitude of future earthquakes. Both the Calaveras and Hayward faults are part of the San Andreas system, which sits at the boundary of two massive slabs of the Earth’s crust called the North American and Pacific plates. The plates slide slowly past one another, sometimes getting stuck and then slipping, releasing energy and causing the Earth to shake. Along the Calaveras and Hayward faults—smaller cracks on top of the plates—the land also moves steadily, a movement that geologists call creep
An asteroid impact 100 miles (170 kilometers) off the coast of Maryland would send waves up to 50 feet (15 meters) high onto the shore an hour later and massive flooding would occur three hours after impact, according to a new computer simulation of hypothetical asteroid impacts. The model is the first of its kind and federal agencies have used it to assess potential hazards arising from such impacts in an effort to increase U.S. emergency preparedness, planning and management, the scientists say.
“Leave no trace.” It’s a central ethic of wilderness exploration. Pack your supplies in, pack your waste out, and leave the natural landscape unspoiled. But when it comes to the newest frontier of exploration—visiting alien worlds to search for evidence of extraterrestrial life—the challenge of avoiding contamination with traces of life from Earth is a huge challenge.
Sooner or later, mountains crumble into boulders, boulders crumble into rocks and pebbles, and so on, until wind and rivers carry sand and dust into the ocean, completing the geologic rock cycle. “But how [rocks] go from the mountain into that ocean bottom, that’s what is not understood very well,” said Jaakko Putkonen, a geologist with the University of North Dakota. Scientists from UND and other institutions discovered that chunks of rock break off of boulders in Antarctica once every 1,900 years on average, and those smaller chunks break apart once every 510,000 years. Putkonen thinks that heat flow through rocks might be responsible for the dramatic difference in how fast bigger rocks crumble compared to smaller rocks. Knowing how fast boulders break down into smaller and smaller chunks will help geologists understand how the mountains crumble to the sea everywhere.
The hardworking AERONET (AErosol RObotic NETwork) instrument in Baengyeong, South Korea was having a rough day. Every 15 minutes, the telescope-like device pointed its barrel at the sun to record its light and measure how much was blocked by airborne particles, or aerosols. July 13, 2012 was an overcast day and the light absorbed by the clouds dominated the measurements. But then, just after 1 p.m., the clouds parted, the instrument looked up, and data was collected. Only no one saw it.
18 December 2014
Earthquakes generate seismic waves that propagate through earth, water, and air. Generations of geologists have used ground-based seismometers to decipher information about earthquakes, including magnitude, epicenter, depth and tsunami danger. But more recently some researchers have wondered if seismic waves traveling through the air also carry traceable information about the earthquake that generated them. If so, measuring seismic waves in the atmosphere could potentially speed up earthquake reporting systems and improve the accuracy of tsunami alerts.
Scientists can use satellites to track wastewater plumes in the ocean, according to new research presented Tuesday afternoon at the American Geophysical Union Fall Meeting in San Francisco. Researchers from NASA Jet Propulsion Laboratory and other research institutions tracked wastewater plumes from the Los Angeles County and Orange County treatment plants in California during maintenance in 2006 and 2012, respectively. Each plant temporarily diverted wastewater into an older, shorter, shallower pipe. But treated sewage still contains contaminants, so each plant also conducted expensive ocean monitoring.
In tanks at the University of Iowa, mussels equipped with heart rate monitors are purifying water with their excrement. Like human heart monitors, the gadgets glued to the mussels’ shells provide information about activity and metabolism. But in the mussels’ case, this information is helping researchers understand how mussels cleanse the water of agricultural runoff.
Michael Wong wants to understand how life could evolve on other worlds. A graduate student in planetary sciences at the California Institute of Technology, he usually focuses on planetary atmospheres. But recently, his quest took Wong to a strange, hostile setting: the bottom of an acidic ocean on Earth, 4 billion years ago.
17 December 2014
Scientists have created a computer system that will help predict malaria outbreaks in northwestern Ethiopia. The advance warning system, which uses local epidemiological information and real-time environmental data, will allow public health officials to transport resources to high-risk areas and contain outbreaks early, explained ecologist Chris Merkord from South Dakota State University.