Roumen.ganeff

Thwaites glacier

NASA/JPL

A large part of the West Antarctic Ice Sheet, a massive expanse of frozen water that flows into the Amundsen Sea, is likely already in the process of collapsing, probably irreversibly. A pair of studies show that part of the sheet is melting more quickly than previously thought, and that several of its large glaciers will probably melt into the ocean, raising global sea levels at least 10 feet in the coming centuries. And it cannot be stopped.

The first study, to be published May 16 in the journal Science, suggests that the Thwaites Glacier, a relatively fast-moving part of the ice sheet, will likely melt away into the ocean within several centuries, enough by itself to raise sea levels 2 feet. Another study to be published in the journal Geophysical Research Letters looked more broadly at Thwaites and other glaciers bordering the Amundsen Sea, and likewise concluded they are collapsing.

The term "collapsing" is perhaps not the best one, because it implies something sudden. These glaciers are expected to melt in the next several centuries, and both studies suggest there is little chance that their runaway melt and slide into the sea will slow down. While not sudden in normal everyday language, it is still quite rapid in geological terms. 

The second study, done in part by NASA researchers, concerns three lines of evidence--collected over the last 40 years--that suggest the glaciers will soon melt away: the changes in their flow speeds, how much of each glacier floats on seawater, and the slope of the terrain they are flowing over and its depth below sea level. Regarding the first, they are flowing more quickly toward sea than before, and this pace is accelerating. Likewise, the amount of floating ice is increasing, and the shape of the sea floor under the ice doesn't appear capable of stopping this increased flow. Specifically, the "grounding line"--where the glaciers cease to lay atop land, and begin rather to float over water, is moving inland quicker than thought, an observation reached by satellite measurements.

Part of the reason this is happening, the researchers think, is because melting makes the ice weigh less, thus causing more of it to float rather than rest on the sea floor. (And as you probably know, floating ice displaces as much water as melted ice.) 

"The collapse of this sector of West Antarctica appears to be unstoppable," said Eric Rignot, a UC Irvine glaciologist who is also with NASA's Jet Propulsion Laboratory, in a statement. "The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating parts of the glaciers. At this point, the end appears to be inevitable."

For more on what the studies say, head over the NBC News. 

In case you hadn't heard, stimulation of the brain with mild electrical currents can in some people induce lucid dreaming: the ability to become self-aware in dreams, and to sometimes control them. 

In the study, the scientists, led by Ursula Voss at the J.W. Goethe University in Frankfurt, Germany, stimulated sleepers' brains using a weak current set to a particular frequency, in a technique called transcranial alternating current stimulation (tACS). Christian Jarrett at Wired has a good rundown of the study: 

The main result is that stimulation specifically delivered in the low gamma range, at 40Hz, and to a lesser extent at 25Hz, was associated with a greater experience of lucid dreaming, as compared to stimulation at other higher and lower frequencies or to sham treatment. “Our experiment is, to the best of our knowledge, the first to demonstrate altered conscious awareness as a direct consequence of induced gamma-band oscillations during sleep,” the researchers concluded.

The researchers define lucid dreams as those in which participants have higher self-reported scores in three areas: self-awareness of dreaming (insight), taking on a third-person perspective (dissociation), and--most intriguing to me--control over one's dreams. As Virginia Hughes wrote at National Geographic, 40 Hz was the "sweet spot" for average scores on these measures. 

However, the ability to control one's dreams spiked at 25 Hz, and showed no increase at 40 Hz. This suggests, as the researchers wrote, "25-Hz oscillatory activity may be functionally distinct from 40-Hz activity." That's really important if you want to be able to control your dreams. Participants experienced 25 Hz or 40 Hz zaps on separate occasions to tell the difference between them. 

I doubt I'm wrong in assuming that control is probably the most desired aspect of lucid dreaming--and is often considered to be intrinsic to lucid dreaming.  This study suggests that there may be something that is distinct about control, or at least that it is elicited in a different way.  I'd be willing to bet that those dreams in which the sleepers took control were more exciting to experience.

While we're on the topic of lucid dreams, here's a Popular Science story from January 2012 about how it is possible to control your dreams, without electricity but with practice. 

The study was published May 11 in the journal Nature Neuroscience.

What Is Fracking?

Hydraulic fracturing, used in 9 out of 10 natural gas wells in the United States, involves pumping millions of gallons of water, sand and chemicals underground to break apart the rock and release the gas. Concern is growing that the chemicals used can harm human health and the environment.

ProPublica

Under the banner of “trade secrets,” many oil and gas companies have refused to reveal all the chemicals they are injecting deep underground, at high pressure, to reach and extract deposits of natural gas and shale oil.

This has increased worries that chemicals from fracking fluids could contaminate underground aquifers and wells used for drinking water, while staying hidden because no one would know what to test for.

That could change in the coming year, however. The Environmental Protection Agency is opening a 90-day public comment period “on what information could be reported and disclosed” about fracking chemicals, “and the approaches for obtaining this information.” EPA apparently wants to consider carrots like “incentives and recognition programs” that might encourage companies to create improved (less toxic) fracking chemicals, as well as regulatory sticks that would force them to reveal their ingredients.

Some states already require firms to reveal cloaked ingredients to state officials or doctors if contamination is suspected, but still leave the general public in the dark, according to Climate Central.

EPA's call for comments comes in part thanks to a 2011 petition by an environmental group, made under the Toxic Subtances Control Act. Earthjustice asked the agency to "require chemical manufacturers and processors to publish detailed information about the content of fluids used in fracking," as well as "that those companies submit all health and safety studies available on those fluid mixtures," according to Reuters.

Two related developments made big fracking news in April:

Houston-based Baker Hughes, one of the world's largest oil field services companies, announced that it would disclose all the chemicals in its fracking fluids, whille keeping their chemical formulae proprietary.

A Texas family won $2.925 million in damages from Aruba Petroleum, when a jury found that fracking operations near the family's 40-acre ranch had harmed their health, water supply, and property value.