University of Alaska Southeast Associate Professor Eran Hood is the second author of the study, to be published in the international journal Nature Geoscience in March 2012 and published on-line this week. "When we look at the marine food webs today, we may be seeing a picture that is significantly different from what existed before the late-18th century," said first author Aron Stubbins of the Skidaway Institute of Oceanography.
Hood led the fieldwork on glaciers in Juneau, Alaska where visiting scholar-scientists from throughout the Lower 48 sampled snow, ice melt, and glacier runoff. The organic carbon from these water and snow samples was isolated and carbon dated. “We analyzed its molecular chemical structure,” said Hood. “The carbon fingerprint we found indicated aerosols derived from the combustion of fossil fuels are an important source of organic matter on glacier surfaces and also in glacier outflow streams.”
The scientists said glaciers like the Mendenhall offer ideal evidence of soot from carbon emissions. This "black carbon," darkens glacier surfaces and increases their absorption of light and heat. The carbon can also be exported to ecosystems downstream from glaciers where it can be metabolized and become part of the food web.
"These findings show that glaciers like Mendenhall can provide us with novel information about how humans are altering the composition of the atmosphere as a result of burning biomass and fossil fuels" said Hood. "The fact that we see this human-derived carbon signature in Alaskan glaciers also indicates that we still do not fully appreciate the post-industrial changes in the earth's surface biogeochemical cycles."
Glaciers and ice sheets together represent the second largest reservoir of water on the planet, and glacier ecosystems cover ten percent of the Earth, yet the carbon dynamics underpinning those ecosystems remain poorly understood. "Improving our understanding of glacier biogeochemistry is of great urgency, as glacier environments are among the most sensitive to climate change and the effects of industrial pollution,” emphasized Rob Spencer of the Woods Hole Research Center, another author on the study.
A warming climate will increase the outflow of the glaciers and the accompanying input of dissolved organic material into the coastal ocean. This will be most keenly felt in glacial coastal regions with the highest levels of ice loss including the Gulf of Alaska, Greenland and Patagonia.
The title of the study is “Anthropogenic aerosols as a source of ancient dissolved organic matter in glaciers.” In addition to Stubbins and Spencer, Hood’s fellow collaborators on the project were Andrew Vermilyea from the University of Alaska Southeast; Peter Raymond and David Butman from Yale University; George Aiken, Robert Striegl and Paul Schuster from the U.S. Geological Survey; Rachel Sleighter, Hussain Abdulla and Patrick Hatcher from Old Dominion University; Peter Hernes from the University of California-Davis; Durelle Scott from Virginia Polytechnic Institute and State University.
More information and a slideshow of photographs by Hood can be found in the U.S. National Science Foundation on-line article, “Scientists Unlock Record of Ecosystem Changes Frozen in World's Glaciers”: http://www.nsf.gov/news/news_summ.jsp?cntn_id=123154Eran Hood
Eran Hood | Newswise Science News
Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen
The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
19.11.2018 | Materials Sciences
19.11.2018 | Information Technology
19.11.2018 | Life Sciences