Featured Research

from universities, journals, and other organizations

Topography of Eastern Seaboard muddles ancient sea level changes

Date:
May 16, 2013
Source:
DOE/Lawrence Livermore National Laboratory
Summary:
The distortion of the ancient shoreline and flooding surface of the US Atlantic Coastal Plain are the direct result of fluctuations in topography in the region and could have implications on understanding long-term climate change, according to a new study.

The reconstructed shoreline of the eastern U.S. at 3 million years ago (colors represent topography in meters). The reconstruction is based on mantle flow and glacial isostatic adjustment over the past 3 million years. The predicted shoreline is in good agreement with geologic inferences which has implications on understanding the past long-term sea level change.
Credit: Image courtesy of DOE/Lawrence Livermore National Laboratory

The distortion of the ancient shoreline and flooding surface of the U.S. Atlantic Coastal Plain are the direct result of fluctuations in topography in the region and could have implications on understanding long-term climate change, according to a new study.

Sedimentary rocks from Virginia through Florida show marine flooding during the mid-Pliocene Epoch, which correlates to approximately 4 million years ago. Several wave-cut scarps (rock exposures), which originally would have been horizontal, are now draped over a warped surface with up to 60 meters variation.

Nathan Simmons of Lawrence Livermore National Laboratory and colleagues from the University of Chicago, Universite du Quebec a Montreal, Syracuse University, Harvard University and the University of Texas at Austin modeled the active topography using mantle convection simulations that predict the amplitude and broad spatial distribution of this distortion. The results imply that dynamic topography and, to a lesser extent, glacial adjustment, account for the current architecture of the coastal plain and nearby shelf.

The results appear in the May 16 edition of Science Express, and will appear at a later date in Science Magazine.

"Our simulations of dynamic topography of the Eastern Seaboard have implications for inferences of global long-term sea-level change," Simmons said.

The eastern coast of the United States is considered an archetypal Atlantic-type or passive-type continental margin.

"The highlight is that mantle flow is a major component in distorting the Earth's surface over geologic time, even in so-called 'passive' continental margins," Simmons said. "Reconstructing long-term global sea-level change based on stratigraphic relations must account for this effect. In other words, did the water level change or did the ground move? This could have implications on understanding very long-term climate change."

The mantle is not a passive player in determining long-term sea level changes. Mantle flow influences surface topography, through perturbations of the dynamic topography, in a manner that varies both spatially and temporally. As a result, it is difficult to invert for the global long-term sea level signal and, in turn, the size of the Antarctic Ice Sheet, using east coast shoreline data.

Simmons said the new results provide another powerful piece of evidence that mantle flow is intimately involved in shaping Earth's surface and must be considered when attempting to unravel numerous long-term Earth processes such as sea-level variations over millions of years.


Story Source:

The above story is based on materials provided by DOE/Lawrence Livermore National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. David B. Rowley, Alessandro M. Forte, Robert Moucha, Jerry X. Mitrovica, Nathan A. Simmons, and Stephen P. Grand. Dynamic Topography Change of the Eastern United States Since 3 Million Years Ago. Science, 16 May 2013 DOI: 10.1126/science.1229180

Cite This Page:

DOE/Lawrence Livermore National Laboratory. "Topography of Eastern Seaboard muddles ancient sea level changes." ScienceDaily. ScienceDaily, 16 May 2013. <www.sciencedaily.com/releases/2013/05/130516182028.htm>.
DOE/Lawrence Livermore National Laboratory. (2013, May 16). Topography of Eastern Seaboard muddles ancient sea level changes. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2013/05/130516182028.htm
DOE/Lawrence Livermore National Laboratory. "Topography of Eastern Seaboard muddles ancient sea level changes." ScienceDaily. www.sciencedaily.com/releases/2013/05/130516182028.htm (accessed July 25, 2014).

Share This




More Earth & Climate News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Virginia Governor Tours Tornado Aftermath

Virginia Governor Tours Tornado Aftermath

AP (July 25, 2014) Virginia Gov. Terry McAuliffe toured the Cherrystone Family Camping and RV Resort on the Chesapeake Bay today, a day after it was hit by a tornado. The storm claimed two lives and injured dozens of others. (July 25) Video provided by AP
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins