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22 December 2014
Jupiter’s moon Europa has tantalized scientists with its potential for harboring life ever since Galileo first spotted the icy satellite in 1610. If living matter is bubbling anywhere in our solar system, they suspect, it would be below the moon’s icy shell, where a presumed ocean of salty water meets a mineral-rich interior. But because scientists can’t peer beneath the ice, they must rely on data beamed back by passing spacecraft. A proposed NASA mission called Europa Clipper could be sent to the moon in the next decade—and researchers from the Massachusetts Institute of Technology and NASA want their instrument to be onboard.
In 1997, a record-breaking El Niño event in the Pacific Ocean brought rain to California, flooding to Peru, and drought to Africa. Earlier this year scientists said that warm currents in the Pacific Ocean presaged the biggest El Niño event since the record-breaking 1997-1998 season. The National Oceanic and Atmospheric Administration put the likelihood of a major Northern Hemisphere El Niño at 80 percent. But despite high expectations, the predicted El Niño of 2014 has ultimately fizzled. In a talk entitled “Who Killed the 2014 El Niño?” at the American Geophysical Union conference Thursday, NOAA oceanographer and past president of AGU Michael McPhaden laid out the leading suspects in this climatic whodunnit – including weak westerly winds, contrary trends elsewhere in the ocean, and overall climate-related ocean warming.
Earlier this year, superheated water within Japan’s Mount Ontake triggered a hydrothermal explosion. Scientists monitoring the volcano had seen no signs of impending danger. The resulting steam-triggered eruption killed 57 people. Clusters of earthquakes often precede major eruptions of lava and ash. The same is not true for smaller steam-triggered eruptions of gas like the Ontake event. But those are the sorts of events that Társilo Girona would like to predict, and he believes that cameras may be the key.
19 December 2014
Scientists have detected electromagnetic signals emanating from Venus’s thick cloud layer, bolstering the case for lightning on the planet. The Venus Express spacecraft, which recently ended its mission after eight years, recorded electromagnetic pulses about 217 miles (300 kilometers) above the planet’s surface, said Richard Hart, a graduate student at the Institute for Geophysics and Planetary Physics at the University of California at Los Angeles.
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.