Lamont Scientists Present Findings on Hidden Dangers of Climate Change, Natural Hazards

December 11, 2007
Dec 10, 2007--Scientists from Columbia University’s Lamont-Doherty Earth Observatory will report this week on vital topics including new evidence of the effects of climate change; technologies to confront it; studies of eastern U.S. earthquake risk; and previously unseen inner workings of the deep polar ice caps.  The reports will be presented at the fall 2007 American Geophysical Union (AGU), the largest earth-sciences gathering in the world, Dec. 10-14 in San Francisco.
 
A sampling of the talks, and contacts for the researchers:
 
A cross-taxa phenological dataset from Mohonk Lake, NY, and its relationship to climate
Since the 1800s, generations of the Smiley family, owners of the historic Mohonk resort, have collected unusually complete long-term records of weather, plant flowerings, and appearances of amphibians, insects and birds. A father-and-son team of climatologists now analyzing the data say that some species are clearly responding to warming--but the picture is more complex than they expected.
 
Abrupt climate change and the collapse of deep-sea ecosystems during the last 20,000 years
Sediment cores from the north Atlantic show a half dozen massive collapses of deep-sea communities coinciding with known sudden climate shifts. The largest paralleled the Younger Dryas cold snap of about 13,000 years ago; there have been several since. Thus, abrupt climate turns seem to penetrate quickly far below the surface.
Peter deMenocal peter@ldeo.columbia.edu (First author: Moriaki Yasuhara, US Geological Survey moriakiyasuhara@gmail.com)
 
Southeast Asian mega-droughts of the past 5 centuries from tree rings and historical records
Natural—and possibly manmade--variations in monsoons across Asia mean life or death for crops. What controls these rains? Rings from newly found ancient trees in remote Vietnam and Laos, plus corals, speleothems and even ancient wood coffins (which contain tree rings) are providing answers. The author thinks a 14th-15th-century drought brought on by weakening of the monsoon may have destroyed Cambodia’s Angkor Wat civilization.
Brendan Buckley bmb@ldeo.columbia.edu
 
A global assessment of deep-sea basalt sites for carbon sequestration
Many scientists now believe that carbon dioxide must be removed from the air in order to address greenhouse warming—but the problem is where to put it where it cannot leak back out. Lamont teams are building evidence that it could be pumped globally into volcanic basalt, whose chemistry is such that it would react with the gas, safely turning it into a solid. Experiments are coming in Washington, Wyoming and Iceland.
David Goldberg goldberg@ldeo.columbia.edu. Related work: Juerg Matter jmatter@ldeo.columbia.edu;  Peter Kelemen peterk@ldeo.columbia.edu
 
Role of subglacial water and tectonics in the onset of fast ice flow
Antarctica’s ice sheets are undergoing startling disintegration and rapid flow in places. New images from under deep ice, generated in a variety of ways, show huge lakes, flowing water and subglacial volcanism. These may be lubricating or otherwise controlling some of the action; such powerful features may interact with climate change in ways that we are still trying to grasp.
 
Relocating and characterizing the 10 Feb 2006 Green Canyon Gulf of Mexico Earthquake
This magnitude 5.2 quake, the region’s largest since the 1970s (an even bigger one has since occurred) came where oil companies are developing large-scale underwater infrastructure, presenting potential for destruction. Because of its unusual high-frequency waves and location away from plate boundaries, its cause is unknown. The investigators are using company data, including measurements of sudden seafloor sinking, to probe further.
Meredith Nettles nettles@ldeo.columbia.edu (First author: J.A. Dellinger, BP dellinja@bp.com.)
 
Forcing by infragravity waves interacting over the deep ocean basins explain ‘Earth’s hum’
The recent discovery that the earth vibrates even without earthquakes has sparked a search for the source, or sources of this constant “hum.” The author says he has pinpointed it in low-frequency ocean waves over deep ocean basins, along with waves over shallower waters.
 
Sediment transport, mixing and erosion by an impact-generated tsunami off Australia
The author has argued for massive, recent meteorite impacts on a scale and frequency not previously accepted. Here she presents the latest work on two large undersea craters where layers of fossils and apparent ejected material suggest they were formed in one great impact that caused a massive tsunami.
 
   For more information on the AGU meeting, go to: http://www.agu.org/

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