Sep 6, 2009

New MIT research by Denise Brehm, Department of Civil and Environmental Engineering, funded by the U.S. Department of Energy looked at the potential for a compound affect of warming global temperatures on the level of methane being released by oceanic vents.

The premise is that rising global temperatures could be accompanied by melting permafrost in arctic regions and that this could initiate the release of underground methane into the atmosphere. Once released, that methane gas would speed up global warming

by trapping the Earth’s heat radiation about 20 times more efficiently than does the better-known greenhouse gas, carbon dioxide.

An MIT paper on this research in the Journal of Geophysical

Research shows how this underground methane in frozen regions could escape and concludes that methane trapped under the ocean may already be escaping through vents in the sea floor at a much faster rate than previously believed. Some scientists have associated the release, both gradual and fast, of subsurface ocean methane with climate change of the past and future.
“The sediment conditions under which this mechanism for gas migration dominates, such as when you have a very fine-grained mud, are pervasive in much of the ocean as well as in some permafrost regions,” said lead author Ruben Juanes, the ARCO Assistant Professor in Energy Studies in the Department of Civil and Environmental Engineering. “This indicates that we may be greatly underestimating the methane fluxes presently occurring in the ocean and from underground into Earth’s atmosphere,” said Juanes. “This could have implications for our understanding of the Earth’s carbon cycle and global warming.”

Methane, the primary component of natural gas, is more abundant in the Earth’s atmosphere now than at any time during the past 400,000 years, according to a recent analysis of air bubbles trapped in ice sheets. Over the last two centuries, methane concentrations in the atmosphere have more than doubled. It is estimated that about 60 percent of global methane emissions are tied to human activities like raising livestock and coal-mining, with the rest tied to natural sources such as wetlands, decomposing forests and underground deposits known as methane hydrates.

In the hydrate phase, a methane gas molecule is locked inside a crystalline cage of frozen water molecules. These hydrates exist in a layer of underground rock or oceanic sediments called the hydrate stability zone or HSZ. Methane hydrates will remain stable as long as the external pressure remains high and the temperature low. Beneath the hydrate stability zone, where the temperatures are higher, methane is found primarily in the gas phase mixed with water and sediment.

But the stability of the hydrate stability zone is climate-dependent.
If atmospheric temperatures rise, the hydrate stability zone will shift upward, leaving a layer of methane gas that has been freed from the hydrate cages. Pressure in that new layer of free gas would build, forcing the gas to shoot up through the HSZ to the surface through existing veins and new fractures in the sediment.

For more information: http://web.mit.edu/newsoffice/2009/methane-0902.html

Sep 6, 2009

Long-term climate records from the Arctic provide strong new evidence that human-caused global warming

can override Earth’s natural heating and cooling cycles, U.S. researchers reported this week in the journal Science

.

For more than 2,000 years, a natural wobble in Earth’s axis has caused the Arctic region to move farther away from the sun during the region’s summer, reducing the amount of solar radiation it receives. The Arctic is now 600,000 miles farther from the sun than it was in AD 1, and temperatures there should have fallen a little more than 1 degree Fahrenheit since then.

Instead, the region has warmed 2.2 degrees since 1900 alone, and the decade from 1998 to 2008 was the warmest in two millenniums, according to a team headed by climatologist Darrell S. Kaufman of Northern Arizona University.

Not only was the last half-century the warmest of the last 2,000 years, “but it reversed the long-term, millennial-scale trend toward cooler temperatures,” Kaufman said.

The results seem to negate the primary argument of those who say the current warming of Earth is simply a natural variation, he said.

The Arctic region has actually warmed about three times as much as the rest of Earth through a well-known effect called Arctic amplification.

As reflective snow and ice melt and are replaced by dark water and vegetated surfaces that absorb more sunlight, trapped heat is released back into the atmosphere. The absorption also thaws permafrost, releasing greenhouse gases such as methane back into the atmosphere to increase warming even more.

The climate warming record was produced from tree rings, glacier ice and cores drilled in 14 lakes around the Arctic.

Layers of sediment provided a proxy for temperatures: thicker layers indicated higher temperatures as water from melting glaciers pushed mud into the lakes, while thinner layers indicated less melting.

All three data sources told the same story — that the Arctic began to warm at the beginning of the Industrial Age in the mid-1800s, when humans began releasing large quantities of carbon dioxide into the atmosphere.

Article continues: http://www.latimes.com/news/nationworld/nation/la-sci-arctic5-2009sep05,0,3388515.story

Sep 6, 2009

There have been a gazillion questionable USB powered devices designed for doing things like heating your morning coffee. But why suck power from your computer’s power supply, when you can harness the movement of your mouse to provide the required juice?

This design has induction coils built into the mouse and mousepad, which generate enough power to heat up a pad under your beverage. I just wonder if your morning joe will get cold if you start typing a long blog post on the keyboard.

I New Idea Homepage

Sep 6, 2009

This is a custom pedal/electric bike I designed and built for school. This slideshow shows the start to finish build of the project. I am doing Metal Fabrication Engineering along side a boiler making apprenticeship. I am looking to head into custom electric motorbikes or the automotive fabrication...
By: TheFullMetalAlchemist

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