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

Illegal Aliens Cleared For U.S. Military Service
2014 10 18
The Pentagon announced a new policy allowing illegal immigrants the opportunity to enlist in the armed forces, Thursday. USA Today reports that the new recruitment policies will focus on people with "high-demand skills" like foreign language acumen and health care training: "For the first time, the program — known as Military Accessions in the National Interest, or MAVNI — will ...
Bronze Age Sundial-Moondial Discovered in Russia
2014 10 16
A strange slab of rock discovered in Russia more than 20 years ago appears to be a combination sundial and moondial from the Bronze Age, a new study finds. The slab is marked with round divots arranged in a circle, and an astronomical analysis suggests that these markings coincide with heavenly events, including sunrises and moonrises. The sundial might be "evidence of ...
Humans may only survive 68 days on Mars
2014 10 15
Space enthusiasts planning a move to Mars may have to wait to relocate: conditions on the Red Planet are such that humans would likely begin dying within 68 days, a new study says. Oxygen levels would start to deplete after about two months and scientists said new technologies are required before humans can permanently settle on Mars, according to the study ...
Tom Sunic’s letter to the US Ambassador to Hungary
2014 10 14
October 11, 2014 Mr. André Goodfriend Chargé d’Affaires Embassy of the United States of America Szabadság tér 12 H-1054 Budapest Dear Mr. Goodfriend, As an American citizen I would hereby like to express my concern over the recent decision by the Hungarian government to ban the National Policy Institute (NPI) conference which had been scheduled to take place in Budapest from October 3 to October 5, 2014. ...
"Vampire grave" found in Bulgaria
2014 10 14
A "vampire grave" containing a skeleton with a stake driven through its chest has been unearthed by a man known as "Bulgaria’s Indiana Jones". Professor Nikolai Ovcharov – a crusading archaeologist who has dedicated his life to unearthing mysteries of ancient civilisations – said that he had made the discovery while excavating the ruins of Perperikon, an ancient Thracian city ...
More News »