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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.
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.
Located about 25 miles north of Houston, Mueschke Cemetery is a historical burial ground. With its oldest headstone dating back to 1849, the cemetery is the resting place for close to 150 people, many of them soldiers killed in 150 years of American wars. But the cemetery is also known to contain dozens of unmarked graves, their locations lost over time. Now, a tool used by geologists and engineers is helping to find them: radar.
The Northern Hemisphere suddenly cooled about 12,800 years ago in an event named the Younger Dryas. Scientists have debated the cause for many years. One widely-believed explanation is that the massive but long gone Lake Agassiz in central Canada rapidly flooded fresh water east down the St. Lawrence River into the northern Atlantic Ocean. That pulse of fresh water interfered with warm ocean currents and triggered the cooling.
The asteroid that smashed into the Yucatan Peninsula a little more than 66 million years ago left behind the Chicxulub crater, but it also left behind something else: iridium, a rare element, which settled in a fine layer all over the world. When scientists discovered this layer between rock strata in the 1980s, it eventually led them to the crater as well, and an explanation for the disappearance of the dinosaurs. But on either side of that layer, which serves as a geological boundary between the Cretaceous and the Paleogene, determining the age of rock is more difficult. This fuzziness makes it harder for paleontologists to piece together the timeline of life’s evolution after the mass extinction, which included the emergence of humans and all other mammals.
16 December 2014
A NASA team utilized satellite data to create a map of past volcanic deposits and modeled the risk to nearby towns. They found one town on a potential lava flow path and a second town at risk for mud flows. The results were presented at Monday’s poster session at the American Geophysical Union’s Fall Meeting. The group’s methodology using satellite images can serve as a template for remotely assessing volcano risk, according to the researchers.
To walruses, ice means life. It’s their home base, their mating ground, and their transportation. As climate change threatens the extent of ocean ice, a new study takes a first step at determining how changing ice conditions are influencing walrus dynamics.
When ocean scientists visit the beach they pack more than sunscreen and a towel – they pack drones. Researchers show in a new study that drones can be used to cheaply and accurately monitor the movement of water in the surf zone in the Gulf of Mexico. The drones provide a new way of documenting the movement of plant and animal plankton, sediments and pollutants, including spilled oil, near the shore.