Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Find Slow Subsidence of Earth's Crust Beneath the Mississippi Delta

03.04.2012
But Gulf Coast sea-level rise rate five times higher now than in pre-industrial times

The Earth's crust beneath the Mississippi Delta sinks at a much slower rate than what had been assumed.

That's one of the results geoscientists report today in a paper published in the journal Earth and Planetary Science Letters.

The researchers arrived at their conclusions by comparing detailed sea-level reconstructions from different portions of coastal Louisiana.

"The findings demonstrate the value of research on different facets of Earth system dynamics over long time periods," says Thomas Baerwald, geography and spatial sciences program director at the National Science Foundation (NSF).

NSF's Directorates for Geosciences and for Social, Behavioral & Economic Sciences funded the research.

"The results provide valuable new insights about the factors that affect shorelines and other locations in the Gulf Coast area now and into the future," says Baerwald.

"Our study shows that the basement underneath key portions of the Mississippi Delta, including the New Orleans area, has subsided less than one inch per century faster over the past 7,000 years than the more stable area of southwest Louisiana," says paper co-author Torbjörn Törnqvist of Tulane University.

The difference is much lower than previously believed.

"Other studies have assumed that a large portion of the Earth's crust underneath the Mississippi Delta subsided at least 30 times faster due to the weight of rapidly accumulating sediments in the delta," says Törnqvist.

The paper, co-authored by Tulane scientists Shi-Yong Yu and Ping Hu, reveals some good news for residents of the New Orleans area.

Large structures such as coastal defense systems could be relatively stable, provided they are anchored in the basement at a depth of 60-80 feet below the land surface.

Shallower, water-rich deposits subside much more rapidly.

However, the study also provides more sobering news.

"These subsidence rates are small compared to the rate of present-day sea-level rise from the Florida panhandle to east Texas," says Törnqvist.

"The rate of sea-level rise in the 20th century in this region has been five times higher compared to the pre-industrial millennium as a result of human-induced climate change."

Sea level has risen more than eight inches during the past century.

"Looking forward 100 years, our main concern is the continued acceleration of sea-level rise due to global warming, which may amount to as much as three to five feet," says Törnqvist.

"We can now show that sea-level rise has already been a larger factor in the loss of coastal wetlands than was previously believed."

Media Contacts
Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Kathryn Hobgood, Tulane University (504) 865-5229 khobgood@tulane.edu
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget is $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives over 50,000 competitive requests for funding, and makes about 11,000 new funding awards. NSF also awards nearly $420 million in professional and service contracts yearly.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov
http://nsf.gov/news/news_summ.jsp?cntn_id=123569&org=NSF&from=news

More articles from Earth Sciences:

nachricht Northern oceans pumped CO2 into the atmosphere
27.03.2017 | CAGE - Center for Arctic Gas Hydrate, Climate and Environment

nachricht Weather extremes: Humans likely influence giant airstreams
27.03.2017 | Potsdam-Institut für Klimafolgenforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>