Local PaleoTemperatures Varied Between 17.7 C (64 F) to 42.3 C (109 F) at Late Cretaceous Coastal Laos

Reconstruction of Late Cretaceous coastal paleotemperature from halite deposits of the Late Cretaceous Nongbok Formation (Khorat Plateau, Laos)

Authors:

Zhang et al

Abstract:

Cretaceous evaporites of the Maha Sarakhan Formation in Thailand (e.g., the Nongbok Formation, Laos) have been studied for almost a century as the huge potash deposits in the world. The consistently high local paleotemperatures should lead to huge salt deposits during the evaporation process. Primary fluid inclusions in halite can provide surface brine water temperatures directly and quantitatively. Until now, there have been no data published from paleotemperature of primary fluid inclusions of Cretaceous halite. The non-marine halite from the Cretaceous Nongbok Formation (Laos) precipitated from shallow brine waters with temperatures of 17.7–42.3 °C.

China Building 10,000 Ton Coast Guard Cutters

Since its formation in 2013 by the consolidation of four previously independent agencies into a single entity (notably excluding the SAR agency), the Chinese Coast Guard has been experiencing phenomenal growth and has become China’s instrument of choice in its “small stick diplomacy” push to claim most of both the South China Sea and the East China Sea.

They commissioned two 4,000 [ton] cutters in January alone. It appears the growth will continue. The Wuchang Shipbuilding Industry Company has just been awarded a contract for four new 5,000 ton cutters, and China Ship-building Industry Corporation has been contracted to build two additional surveillance ships, one of 10,000 tons and another of 4,000-tons.

The US Coast Guard’s largest patrol cutters are the 418 foot, 4,500 ton full load Bertholf Class National Security Cutters. The illustration that accompanies the story of the four new 5,000 ton cutters shows a ship, in many ways similar to the National Security Cutter. It appears there is a medium caliber gun on the bow. (This would be a significant but not unexpected change for the Chinese Coast Guard.) There is a frame over what appears to be a stern ramp not unlike that on the NSC.

he “10,000 ton” cutter is likely to look similar to the Japanese Coast Guard’s two 492 foot, 9,350 full load, Shikishima class high endurance helicopter carrying cutters [...], but they may actually be much larger. Comparing their new ship to the Japanese cutters, the displacement of the Japanese ships was quoted as 6,500 tons, their light displacement. If the 10,000 tons quoted for the Chinese cutter is also light displacement, it could approach 15,000 tons full load. As reported here the new Chinese OPV will have a 76mm gun, two 30mm guns, facilities to support two Z-8 helicopters, and a top speed of 25 knots.

The size of the helicopters is notable. The Z-8 is a large, three engine, 13,000 kg helicopter based on the Aérospatiale SA 321 Super Frelon. The transport version of this helicopter can transport 38 fully equipped troops. The same airframe is also used for SAR, ASW, and vertical replenishment.

Undoubtedly the new vessels tonnage would give it an advantage in any sort of “shoving match” with vessels of other coast guards, but why so large?

link.

Why is the Sea Level Rising Faster Than Projected?

Sea levels are rising faster than expected from global warming, and University of Colorado geologist Bill Hay has a good idea why. The last official IPCC report in 2007 projected a global sea level rise between 0.2 and 0.5 meters by the year 2100. But current sea-level rise measurements meet or exceed the high end of that range and suggest a rise of one meter or more by the end of the century.

"What's missing from the models used to forecast sea-level rise are critical feedbacks that speed everything up," says Hay. He will be presenting some of these feedbacks in a talk on Sunday, 4 Nov., at the meeting of The Geological Society of America in Charlotte, North Carolina, USA.

One of those feedbacks involves Arctic sea ice, another the Greenland ice cap, and another soil moisture and groundwater mining.

"There is an Arctic sea ice connection," says Hay, despite the fact that melting sea ice -- which is already in the ocean -- does not itself raise sea level. Instead, it plays a role in the overall warming of the Arctic, which leads to ice losses in nearby Greenland and northern Canada. When sea ice melts, Hay explains, there is an oceanographic effect of releasing more fresh water from the Arctic, which is then replaced by inflows of brinier, warmer water from the south.

"So it's a big heat pump that brings heat to the Arctic," says Hay. "That's not in any of the models." That warmer water pushes the Arctic toward more ice-free waters, which absorb sunlight rather than reflect it back into space like sea ice does. The more open water there is, the more heat is trapped in the Arctic waters, and the warmer things can get.

Then there are those gigantic stores of ice in Greenland and Antarctica. During the last interglacial period, sea level rose 10 meters due to the melting of all that ice -- without any help from humans. New data suggests that the sea-level rise in the oceans took place over a few centuries, according to Hay.

"You can lose most of the Greenland ice cap in a few hundred years, not thousands, just under natural conditions," says Hay. "There's no telling how fast it can go with this spike of carbon dioxide we are adding to the atmosphere."

This possibility was brought home this last summer as Greenland underwent a stunning, record-setting melt. The ice streams, lubricated by water at their base, are speeding up.

Hay notes, "Ten years ago we didn't know much about water under the Antarctic ice cap." But it is there, and it allows the ice to move -- in some places even uphill due to the weight of the ice above it.

"It's being squeezed like toothpaste out of a tube," explains Hay. The one thing that's holding all that ice back from emptying into the sea is the grounded ice shelves acting like plugs on bottles at the ends of the coastal glaciers. "Nobody has any idea how fast that ice will flow into the oceans once the ice shelves are gone."

Another missing feedback is the groundwater being mined all over the world to mitigate droughts. That water is ultimately added to the oceans (a recent visualization of this effect in the U.S. was posted by NASA's Earth Observatory).

All of these are positive feedbacks speeding up the changes in climate and sea-level rise.