Tag Archives: ocean

New jellyfish spotted at 2 miles depth

A NOAA mapping robot working two miles beneath the ocean surface recently captured video of a species of jellyfish previously unknown.

The newly discovered jellyfish has two sets of tentacles, short and long. When the the long tentacles are even and extended outward, and the bell is motionless, this could mean it’s readying to ambush its prey, scientists speculate. Inside the bell, red radial canals connect what scientists say looks like the bright yellow gonads.

I have posted the video below the fold.
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Natural methane plumes found on the sea floor

The uncertainty of science: Scientists have discovered hundreds of natural methane sea-floor seeps that had not been predicted by theory.

The bubble streams showed up on sonar scans of the sea floor taken between September 2011 and August 2013 during oceanographic expeditions ranging from Cape Hatteras in North Carolina to Georges Bank off Cape Cod. Altogether, researchers analysed data covering a 94,000-square-kilometre arc (an area about the size of Indiana or Hungary) that includes the edge of the continental shelf and the steep slope just seaward of it, says co-author Adam Skarke, a geologist at Mississippi State University in Starkville. Within a distance of about 950 kilometres, the team found about 570 bubble plumes — an astounding number considering that scientists had previously reported only a handful in the region, he notes.

The article’s first two paragraphs breathlessly attempt to link these plumes to human-caused global warming, noting that there is theory that a warming ocean could produce such methane seeps. Worse, the article adds, once this methane is released it will accentuate warming, as methane is a very powerful greenhouse gas.

The article’s last paragraph, however, finally tells us the real story. Hard data gathered by remote robot vehicles that have actually visited these kinds of plumes instead suggests that the plumes have been there for more than a thousand years and thus could have nothing to do with human-caused global warming. In fact, their natural existence is a significant problem for most climate theories, as they now have to account for this additional greenhouse gas, naturally produced.

Data of the tidal fluxes on Titan by the Cassini spacecraft now suggest that there is a liquid ocean below Titan’s icy crust.

Data of the tidal fluxes on Titan by the Cassini spacecraft now suggest that there is a liquid ocean below Titan’s icy crust.

The team’s analyses suggest that the surface of the moon can rise and fall by up to 10 metres during each orbit, says Iess. That degree of warpage suggests that Titan’s interior is relatively deformable, the team reports today in Science1. Several models of the moon’s internal structure suggest such flexibility — including a model in which the moon is solid but soft and squishy throughout. But the researchers contend that the most likely model of Titan is one in which an icy shell dozens of kilometres thick floats atop a global ocean. The team’s findings, together with the results of previous studies, hint that Titan’s ocean may lie no more than 100 km below the moon’s surface.

Cassini directly samples the plumes from Enceladus and finds an ocean-like Spray

Cassini has directly sampled the plumes from Enceladus and discovered a salty ocean-like spray.

The new paper analyzes three Enceladus flybys in 2008 and 2009 with the same instrument, focusing on the composition of freshly ejected plume grains. The icy particles hit the detector target at speeds between 15,000 and 39,000 mph (23,000 and 63,000 kilometers per hour), vaporizing instantly. Electrical fields inside the cosmic dust analyzer separated the various constituents of the impact cloud.

The data suggest a layer of water between the moon’s rocky core and its icy mantle, possibly as deep as about 50 miles (80 kilometers) beneath the surface. As this water washes against the rocks, it dissolves salt compounds and rises through fractures in the overlying ice to form reserves nearer the surface. If the outermost layer cracks open, the decrease in pressure from these reserves to space causes a plume to shoot out. Roughly 400 pounds (200 kilograms) of water vapor is lost every second in the plumes, with smaller amounts being lost as ice grains. The team calculates the water reserves must have large evaporating surfaces, or they would freeze easily and stop the plumes.