Earth’s Mantle Affects Sea Level Rise Estimates
2013 05 17

By Becky Oskin | OurAmazingPlanet



A prehistoric shoreline runs along the eastern edge of North America; scientists have pointed to it as evidence that much of Antarctica melted 3 million years ago. But new research suggests this shoreline is actually about 30 feet (10 meters) lower than previously thought, meaning less ice melted than suspected.

The shoreline, which should be flat, also swoops up and down the East Coast like a set of wave crests, reflecting tugging and pushing by Earth’s mantle, the layer of viscous rock leisurely oozing underneath the crust, according to the study, published today (May 16) in the journal Science Express.

The finding shows that scientists have to be careful when looking at Earth for evidence of past sea level changes from the planet’s cycles of glacial advance and retreat.

"You simply can’t go somewhere and look at the height of the shoreline and infer anything about the amount of water in the oceans or the height of sea level without already knowing an awful lot about what the mantle is doing," said David Rowley, lead study author and a geologist at the University of Chicago.


The East Coast shoreline as it appeared 3 million years ago. The shoreline has been adjusted 82 feet (25 meters) relative to today.

This interplay between the surface elevation of the Earth and the mantle is called dynamic topography. The cliffs of the Great Australian Bight and the tall height of the African continent are also attributed to the mantle’s effects on topography. Even the Appalachian Mountains may owe their enduring height to the mantle.

[...]

Read the full article at: news.yahoo.com




Related Articles
Sea levels "will continue rising regardless of greenhouse gas treaties", warn scientists
Sea Level Research (2010)
Rise of sea levels is "the greatest lie ever told"
New sat data shows Himalayan glaciers hardly melting at all
World misled over Himalayan glacier meltdown
Climate Paradox: Longer Antarctic Melt Season May Mean Less Global Warming?
Antarctica warmth ’unusual, but not unique’
Amount of ice in Bering Sea reaches all-time record
Arctic freshening not due to ice melt after all, says NASA


Latest News from our Front Page

Norway Joins the Race to Develop Killer Robots
2014 10 24
Norway is a large exporter of weapons, which makes the resolution of the debate about creating killer robots an important issue for everyone.  One could debate the overall merits or failings of robotic systems, but an area that clearly has become a point for concern on all sides is the emergence of "killer robots." According to robotics pioneer, David Hanson, ...
Gene That Once Aided Survival in the Arctic Found to Have Negative Impact on Health Today
2014 10 23
In individuals living in the Arctic, researchers have discovered a gene variant that arose thousands of years ago and most likely provided an evolutionary advantage for processing high-fat diets or for surviving in a cold environment; however, the variant also seems to increase the risk of hypoglycemia, or low blood sugar, and infant mortality in today’s northern populations. {snip} “Our work ...
The Ebola hoax: questions, answers, and the false belief in the “One It”
2014 10 23
“The Reality Manufacturing Company doesn’t just sell ‘fake paintings’ that are easy to spot. No. They also sell images that are geared to mesh with people’s deeply held instincts and thereby produce rigid false beliefs. People are sure that if they gave up such beliefs, their world would fall apart and blow away in the wind.” ...
New Controversial Theory Suggests "Hobbits" Were Not Human - Who Were These Mysterious Beings?
2014 10 23
The origin of the Hobbit species remains a challenging subject to scientists. The Hobbit’s discovery confirmed the view that the Earth was once populated by many species of human, but new research the Hobbit’s were not human at all! So, who were these mysterious beings? Where did they come from? The idea that our species, Homo sapiens, was the only species of human on ...
Right into enemy hands? ISIS shows off new weapons allegedly airdropped by US (VIDEO)
2014 10 23
Islamic State has published a new video in which a jihadist shows off brand-new American hardware, which was purportedly intended for the Kurds they are fighting in the Syrian border town of Kobani. The undated video, posted by the unofficial IS mouthpiece “a3maq news”, sees a jihadist showing several boxes of munitions with English-language markings, with a parachute spread out on ...
More News »