Monday, 11 July 2011

The Battle of the Bulge

National Geographic News tells us:

Earth Has "Spare Tire"—And Ice Melt's Keeping It That Way 
Waistline bulge has stopped slimming, thanks to massive melting.
Earth isn't losing its "spare tire" as fast as it should be, according to new research—and it's definitely not because the planet's not getting enough water.
In fact, melting ice from Antarctica and Greenland (map) is giving the oceans huge infusions of water, which then gets pulled toward the Equator—counteracting a millennia-old slimming trend around the planet's middle, experts say. 
Overall, the current ice loss is causing Earth's bulge to grow at a rate of seven millimeters a decade, Wahr and Nerem found—exactly enough to counteract the long-term rebound, at least temporarily.

This must mean that sea-level rise in the equatorial regions is higher than elsewhere, so let's look at a few places. The largest open body of water is the Pacific ocean, and Hawaii isn't that far from the equator (21°N)
 Hmmm - 1.5 mm/yr is rather less than the global average, and that looks suspiciously like a downturn after 2003 to me. Let's move a little closer to the "bulge" - Johnston Atoll is 15°N

Oh dear - the closer we move to the equator, the lower the rise, and for the coral atoll, about the same level as in 1960, with a few ups and downs in between. Go for broke, and find a country on the equator with a Pacific shoreline. La Libertad, Ecuador fits the bill at 2°S

That's not good (except for the inhabitants).

Darwin, Australia is only 12°S of the equator

Of course, there may be local factors I'm not aware of, but you can't ignore tide gauge data, and doing so lays a fine theory open to question.

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