When glaciers advanced over much of the planet's surface during the last ice age, what kept  Earth from freezing over entirely?  Climate scientists are unsure because popular numerical models indicated that over the past 24 million years geological conditions should have caused carbon dioxide levels in the atmosphere to plummet, possibly leading to runaway "icehouse" conditions - yes, we needed CO2-related global warming, they said - but researchers writing in Nature claims plants are a missing piece of the puzzle.

Very cool news- a ROV recently dove to the Challenger Deep in the Mariana Trench.  Here's the basics over at Discover.

I can't wait until they release more images.  It's very exciting that technology is starting to catch up with our desire to know more about the oceans, and pictures of crazy ocean critters are good attention-getters, particularly for my students.  (Also, the kid inside me can't help but hope that the bottom of the Marianas Trench is kinda like this.)

The potential contribution to sea level rise from a collapse of the West Antarctic Ice Sheet (WAIS) have been greatly overestimated, according to a new study in Science.   These scientists estimate global sea level would rise 3.3 metres, not five or six, which were some previous estimates.

You probably envision ocean currents as a 'conveyor belt'  - that's okay, so do oceanographers.  But at least in the Atlantic, it doesn't work quite the way scientists have believed, according to new research led by Duke University and the Woods Hole Oceanographic Institution.  Their analyses showed that much of this water, originating in the sea between Newfoundland and Greenland, rather than flowing southward from the Labrador Sea, is diverted generally eastward by the time it flows as far south as Massachusetts. From there it disperses to the depths in complex ways that are difficult to follow.

Most of the world's glaciers are retreating as the planet gets warmer but some, including glaciers south of the equator in South America and New Zealand, are growing.

At least for New Zealand glaciers, scientists have offered an explanation: for the last 7,000 years, they have often moved out of step with glaciers in the Northern Hemisphere, pointing to strong regional variations in climate, the authors write in Science.

Conventional wisdom holds that during the era of human civilization, climate has been relatively stable. The new study is the latest to challenge this view, by showing that New Zealand's glaciers have gone through rapid periods of growth and decline during the current interglacial period known as the Holocene.
 

The threat of global warming can still be greatly diminished if nations cut emissions of heat-trapping greenhouse gases by 70 percent this century, according to a new analysis. 

While global temperatures would rise, the most dangerous potential aspects of climate change, including massive losses of Arctic sea ice and permafrost and significant sea-level rise, could be partially avoided.

"This important study, when taken with similar efforts, will help define a major challenge for society," says Cliff Jacobs of NSF's Atmospheric Sciences Division.

Because global warming - whoops, climate change - became a political football rather than a scientific one, there are a lot of people attacking methodology and motive.   1990 does seem like a pretty arbitrary date for CO2 emissions until you realize that's right after the merger of Germany and all they, a key advocate of proponent, had to do to meet their target was close some World War 2 era Soviet factors in East Germany to meet their target.  And France just had to open up some more nuclear power plants (no CO2, but do American environmentalists think that is better?).

The latest data from NASA and the University of Colorado at Boulder's National Snow and Ice Data Center show the continuation of a decade-long trend of shrinking sea ice extent in the Arctic, including new evidence for thinning ice as well.

The researchers, who have been tracking Arctic sea ice cover with satellites since 1979, found that the winter of 2008-09 was the fifth lowest maximum ice extent on record. The six lowest maximum events in the satellite record have all occurred in the past six years, according to CU-Boulder researcher Walt Meier of NSIDC.

The Antarctic landmass is losing its frontier status.  Housing thousands of decreasingly rugged inhabitants in heated, internet-ready comfort, it’s been so well-mapped that we even know where to find the donuts.  Underwater, however, is a different story.  Harsh temperatures, currents, pressure and ice surfaces have kept the submerged landscapes of glaciers inaccessible to all but penguins and Morgan Freeman’s voiceover.

A joint US-British team has nominated a new Ernest Shackleford to explore the uncharted Antarctic underwater.  But this time around, he’s a robot.

Scientists identified seven new species of bamboo coral discovered in the deep waters of the Papahānaumokuākea Marine National Monument. Six of these species may represent entirely new genera, a remarkable feat given the broad classification a genus represents. A genus is a major category in the classification of organisms, ranking above a species and below a family. Scientists expect to identify more new species as analysis of samples continues.
   

Contrary to popular belief (trekkies especially) space is not yet the final frontier - we still have plenty of  unexplored frontier closer to home yet farther away from pop culture imagination: the oceans.  The deep ocean remains one of the last truly explored regions, and it remains almost as mysterious as any distant galaxy. 

According to Discovery Channel’s epic documentary, Blue Planet, Seas of Life, "Over 60% of our planet is covered by water more than a mile deep. The deep sea is the largest habitat on earth and is largely unexplored. More people have traveled into space than have traveled to the deep ocean realm."

The phenomenon of light emission by living organisms, bioluminescence, is quite common, especially in marine species. It is known that light is generated by chemical reactions in which oxygen molecules play an important part. In the animal world, these chemical reactions take place in special luminescent cells called photocytes. These are aggregated into complex light organs, in which the intensity of light is regulated by nerve impulses, and in which light can be modulated with the help of reflectors, lenses and filters. By these means, organisms can adjust the wavelength, diffusion and intensity of light according to need. But the exact mechanisms behind these processes remain shrouded in mystery.

Right now we have a tandem situation. Jason-1 and Jason-2 are flying in tandem above our heads. Sounds like fun perhaps, but who cares? And who are Jason and what's with the numbers, anyways?

Google Earth has the answer to this question, apparently.  Developers are starting to include ocean floor data in the maps accessible via the program.  It's about time, really- but first I have to vent a bit... 

Are you ready for a treat? Have you ever wished you could be with Charles Darwin on his travels just for one day? Perhaps -- when he first saw immense glaciers? Well, I've arranged today to imagine what-and-where of him and the Beagle in South America. Charles Darwin enjoyed 29 January 1833 because his notes are joyful and eventful. See for yourself.

Dumping tires in the water to create an artificial reef sounds either inspired or crazy.  It turned out to be crazy but there was a scientific hypothesis to it.  You just had to buy into their chain of logic.

There was also a lesson.   Not everything needs to be done in a large experimental setting but the justification to go ahead and do it is always cost and the protecting the environment right now.   'You care about the environment, right?'   I can't think of a single time a question has been phrased that way that someone hasn't tried to sell me something.  And the cost savings are always framed to be immediately practical, though in the case of the artificial reef made of tires, the cost to clean up was 5000 times as much as it was supposed to save.

Dead zones are low-oxygen areas in the ocean where higher life forms such as fish, crabs and clams are not able to live.   In shallow coastal regions, for examples, dead zones can be caused by runoff of excess fertilizers from farming.

A team of Danish researchers is projecting that unchecked global warming would lead to a dramatic expansion of low-oxygen areas zones in the global ocean by a factor of 10 or more.

Whereas some coastal dead zones could be recovered by simply controlling fertilizer usage, expanded low-oxygen areas caused by global warming might remain for many years. The findings are reported in a paper 'Long-term ocean oxygen depletion in response to carbon dioxide emissions from fossil fuels' in Nature Geoscience. 

The consensus among scientists has been that while much of the globe has been getting warmer, a large part of Antarctica – the East Antarctic Ice Sheet – has actually been getting colder.   Not so, say Eric Steig, a University of Washington professor of Earth and space sciences, and colleagues in Nature.

Michael Shermer of Michael Shermer: What Will ET Look Like? has inspired me to write a sci fi. Shermer's ET, whether a bipedal primate or not, is attractive for a theme of oceans and humans -- both representing new experiences. An extraterrestrial, you might agree, is also ideal to ask questions to our hero, as suggested by me, to be played by Michael Shermer.