You are browsing the archive for lhwang.
18 December 2015
Exposure to dangerous contaminants in Ulaanbaatar, Mongolia could increase by 10 percent or more by 2024, exacerbating health problems in one of the most polluted cities in the world, a new study finds.
Residents of Ulaanbaatar, the most populous city in Mongolia, rely heavily on coal to survive frigid winters in a valley where air pollution is easily trapped. Air pollution in Ulaanbaatar caused an estimated 1,250 premature deaths in 2014, according to Drew Hill, a graduate student in environmental health at the University of California, Berkeley. Hill was part of a research team that presented an air pollution and health report to the Mongolian Ministry of the Environment and Green Development in the summer of 2014.
Deforestation threatens to upset the delicate water balance within the Amazon rainforest by altering not just ground cover but patterns of rainfall overhead, according to a new study.
Previous research has shown that during the dry season, areas of the Amazon cleared for cattle grazing get more rainfall than the surrounding forest. But most of this research was conducted in the 1980s, when the Amazon was deforested in small patches only a few kilometers wide, said Jaya Khanna, a researcher at Princeton University and lead author of the new study. Khanna’s is the first long-term study of the effects of deforestation on precipitation in the Amazon. Her results, presented at the 2015 American Geophysical Union Fall Meeting, show that rainfall patterns in cleared areas today are vastly different from those in the 1980s.
17 December 2015
The oil or gas leaks that grab headlines tend to be big events such as the Deepwater Horizon spill in 2010, but smaller-scale spills can be a problem, too, new research finds. Even a few drops dribbled from the nozzle of a gas station fuel pump can penetrate concrete and contaminate soil and groundwater below, according to researchers at Johns Hopkins University in Baltimore, Maryland.
In the past, regulators and researchers assumed that most spilled fuel would evaporate into the atmosphere, said Markus Hilpert, a hydrologist at Johns Hopkins University. The possibility that small fuel droplets might seep through the concrete pad under a gas station to the soil and water below was largely ignored, he said.
Harbor seals are the most widespread pinniped species in the world. They range as far south as Baja California in Mexico, and as far north as Artic Canada and Greenland. In the colder areas of that vast distribution, they sometimes make themselves at home on floating chunks of ice below tidewater glaciers.
Glaciers are constantly on the move, flowing slowly downhill under the force of their own weight. When that path leads them into the ocean, they’re called tidewater glaciers. During the summer, harbor seals, up to several thousand at a time, congregate in Alaska’s tidewater glacier fjords.
Scientists use radiocarbon dating to determine the age of everything from bone and teeth to seeds and straw. The accuracy and precision of those dates depends on careful calibration. New data from logs unearthed in a small floodplain in New York’s Lake Ontario lowlands will allow scientists to refine the calibrations for a 1,200 year period that occurred about 12,000 years ago, according to Carol Griggs, a dendrochronologist at Cornell University in Ithaca, New York.
The record represents “a new independent radiocarbon series for this time period,” Griggs said at the 2015 American Geophysical Union Fall Meeting in San Francisco.
As Saturn’s largest moon, Titan earns its name. It’s also the only known body other than Earth with seas, numerous surface lakes, and even rainy weather. Now scientists have mapped out Titan’s polar lakes for the first time, revealing information about the moon’s climate and surface evolution. They found that the lakes formed differently than had been previously thought—and differently than any lakes on Earth.
A collaboration of scientists led by Alexander Hayes of Cornell University presented their findings at the 2015 American Geophysical Union Fall Meeting. They used NASA’s Cassini spacecraft to penetrate Titan’s smoggy atmosphere and probe the complex lake systems below.
The vinegar volcano is a stale science experiment. But Italian geologist Valeria Cigala takes the tired demonstration to a violent new level…
16 December 2015
When faced with the threat of large Earth-bound asteroids, some have suggested deflecting the rocky bodies by striking them with large objects. Others prefer to nuke them. But planetary astronomer Michael Busch takes a less violent approach: he suggests we deflect dangerous asteroids without ever touching them.
Busch, an astronomer at the Search for Extraterrestrial Intelligence (SETI) Institute in Mountain View, California, studies gravity tractors: special spacecraft designed to pull problem asteroids away from destructive trajectories and onto benign paths. He said the technology could come alive within the next decade through NASA’s Asteroid Redirect Mission. Busch presented his team’s research on gravity tractors at the 2015 American Geophysical Union Fall Meeting in San Francisco.
15 December 2015
Nestled in the Arctic is a glacier like no other. This glacier quakes once a minute creating seismic events that rattle the earth—more frequently than scientists have ever seen. Understanding why these icequakes are so common may help researchers predict future ice flow, a process that propels climate-driven sea level rise.
When carbon dioxide and hydrogen gas mingle deep underground, they transform into methane and water—the building blocks of life.
Scientists once thought the reaction, called Sabatier synthesis, could only proceed above 150 degrees Celsius. Life, they thought, was conceived deep in the scalding vents of an ancient ocean. But the Sabatier process also runs cooler, finds a new study presented at the 2015 American Geophysical Union Fall Meeting. With the right catalyst, the reaction works at room temperature, the study found.