The Dec. 13-17 meeting of the American Geophysical Union, the world’s largest gathering of earth scientists, includes many important talks from scientists at Lamont-Doherty Earth Observatory. Below: a small selection that has been flagged to the many reporters attending the meeting. To see abstracts, use ID numbers to search AGU’s program at: http://www.agu.org/meetings/fm10/program/index.php.
Destruction of Antarctic Ice by a Warming Ocean
In the face of dramatic melting along the western Antarctic coast and quickening movement of glaciers to the sea, researchers are reaching a consensus that these changes are probably being driven not so much by warming air as by warm ocean waters increasingly undermining the ice front. Martinson, a 20-year veteran of Antarctic research voyages, will describe startlingly large increases in ocean heat since the 1960s, and their possible roots in global warming and shifting winds and water currents.
Mon., Dec. 13, 1:55-2:10pm. 3011 Moscone West. C13D-02
The Haiti Quake Undersea
Weeks after the 2010 Haiti quake, researchers mounted a cruise along the battered coast
to collect sediment cores, sonar images and other samples aimed at understanding the mechanisms of the quake and a subsequent tsunami. Among other things, they found signs of underwater landslides, a 600-meter-deep layer of still-turbid water, and sediment layers signaling at least four previous big quakes. It is the first time that scientists have studied a large quake on the seafloor so soon afterward, and it opens the door to understanding future threats in Haiti and elsewhere, including the Mediterranean.
Mon., Dec. 13, 1:40-6pm. Poster Hall. U13A-0007
(Related: Positive Feedback Between Faults in January 2010, U13A-0006. Leonardo Seeber, LDEO, firstname.lastname@example.org
. Same time and place.
New York City Trees and Carbon Dioxide, Past and Present
A tree grows in Brooklyn—very nicely, it turns out—and researchers are looking into whether this has anything to do with the heightened CO2 levels of an urban setting or globally increasing CO2. Instruments recently set out across the city and beyond are measuring CO2 to produce a rare map of local-scale levels; meanwhile, tree rings have allowed scientists to plot changing levels over the last 150 years. Among the surprising findings: Central Park air has little more CO2 than air in Greenland; city emissions per capita have declined since the 1950s; and urban trees grow better than country cousins--but this last may have more to do with heat or other gases than CO2. Such studies touch upon how trees and plants may interact with changing temperatures and CO2 levels in the future, and thus possibly mitigate or exacerbate warming climate.
Mon., Dec. 13, 1:40-6pm. Poster Hall. A13F-0284
Estimating the True Size of the Gulf Oil Spill
After a BP oil well blew up in the Gulf of Mexico, officials initially said the rate of oil leaking could not be measured; but Crone and colleagues argued publicly that reliable methods existed, and proceeded to employ them
. Crone’s method—optical plume velocimetry, a video-analysis technique used to study flows from natural hydrothermal vents—indicated a spill rate of more than 50,000 barrels a day, or ten times initial estimates. With public pressure mounting in the months after the spill, the government convened a group to study the flow; its estimates now substantially agree with Crone’s.
Tues., Dec. 14, 8:30-8:45am. 3009 Moscone West. OS21G-03
World at Your Fingertip: The Earth Observer App
Be one of the first to experience the new Earth Observer app
, which gives the public i-phone access to fabulously detailed (and fun) maps, images and data previously tapped mainly by scientists. The creators will demonstrate how to pull up visuals of seafloors, volcanoes, moving tectonic plates, permafrost, rock types, plant cover, temperatures and dozens of other things—all with a few touches of the fingers. Follow meandering canyons in the deep Pacific; zoom into ripple marks in New York harbor; plot plankton productivity, human populations and earthquake dangers. Even includes topo maps used by hikers and U.S. offshore nautical charts—all to street-level magnification. Much of the data is updated monthly. Out this week at the Apple i-tunes store
Tues., Dec. 14 thru Thurs., Dec. 16, 9:30am-5pm; Friday, Dec. 17, 9:30am-1:30pm
Exhibit Hall, Moscone West, Booth 249
(Related: “Advancing Access of Earth and Ocean Science Data.” Kerstin Lehnert, LDEO. Mon., Dec. 14, 3:25-3:40pm. 302 Moscone South. IN13B-08)
The Great Ocean Conveyor
Broecker, a leader in studying climate for five decades, helped pioneer the idea that the oceans circulate great masses of heat among various parts of the world, and thus may be capable of triggering huge, abrupt changes. Here, he discusses the “bumpy ride” he has experienced in trying to understand the ocean system, as detailed in his most recent book, The Great Ocean Conveyor
Wed., Dec. 15, 10:20-10:40am. 103 Moscone South. GC32A-01
(Related: Broecker on “Why Was the World Dustier During Times of Glaciation?” Mon., Dec. 13, 10:20-10:35am. 2007 Moscone West. PP12A-01
New York City Droughts, From the 1500s to the Future
In the past 10 years, New York City has struggled to maintain adequate water reserves; and in the future, population growth and climate change (projected to make rainfall more erratic) may worsen things. Adding to concerns, Pederson has now used tree rings to show recent dry spells have been minor compared to past ones. With samples from rare old surviving trees and beams from historical buildings from New Jersey to the Adirondacks, he has traced rainfall from the 1500s on, identifying huge droughts in every century through the 1800s, while those of the last 120 years have been relatively short-lived. This suggests that the city may not be prepared for future droughts, if history repeats itself.
Wed., Dec. 15, 1:40-1:55pm. 3006 Moscone West. A33J-01
Remote Triggering of Earthquakes: What Does It Take?
The once-exotic idea that earthquakes can have ripple effects by triggering quakes on separate, faraway faults has recently gained currency. But how much shaking does it take to push remote faults over the edge? This probably depends on how close they are to failing already—and that is one of the most elusive qualities in seismology. Savage’s preliminary data suggests that triggering of faults along subduction zones in Alaska and Costa Rica depends highly on shaking amplitude, but faults in the U.S. Midwest, far from any tectonic boundaries, show a weaker relationship. It suggests that “intraplate” faults like Midwestern ones spend less time teetering on the edge of failure than those in tectonically active places.
Thurs. Dec. 16, 8am-12:20pm. Poster Hall. T41B-2133
The Last Arctic Sea Ice Refuge
The fast disappearance of summer sea ice in much of the Arctic may spell doom for creatures such as polar bears, which depend on sea ice for habitat. Looking forward, Pfirman and colleagues are investigating whether thick ice may persist
in at least some parts, and serve as a refuge to arctic ecosystems. Studies of past environments, ice-formation patterns, currents and winds suggest that a possible future refuge may lie in at least one region where ice already tends to collect—but to make it work, planners will have to consider mining, transportation, tourism and other possible competitors with wildlife.
Thurs., Dec. 16, 1:40-6pm. Poster Hall. C43E-0592
(Related: “Shifting Arctic Sea-Ice Formation and Melt Patterns in a Warming World.” Robert Newton. Same time and place. C43E-0593)
Related Link: American Geophysical Union Fall Meeting 2010 - EI Blog