Featured Research

from universities, journals, and other organizations

Saharan dust is key to formation of Bahamas' Great Bank, study finds

Date:
July 24, 2014
Source:
University of Miami Rosenstiel School of Marine & Atmospheric Science
Summary:
Saharan dust played a major role in the formation of the Bahamas islands, a new study suggests. Researchers showed that iron-rich Saharan dust provides the nutrients necessary for specialized bacteria to produce the island chain's carbonate-based foundation. Persistent winds across Africa's 3.5-million square mile Sahara Desert lifts mineral-rich sand into the atmosphere where it travels the nearly 5,000-mile northwest journey towards the U.S. and Caribbean.

This is the Great Bahama Bank.
Credit: NASA

A new study suggests that Saharan dust played a major role in the formation of the Bahamas islands. Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science showed that iron-rich Saharan dust provides the nutrients necessary for specialized bacteria to produce the island chain's carbonate-based foundation.

UM Rosenstiel School Lewis G. Weeks Professor Peter Swart and colleagues analyzed the concentrations of two trace elements characteristic of atmospheric dust -- iron and manganese -- in 270 seafloor samples collected along the Great Bahama Bank over a three-year period. The team found that the highest concentrations of these trace elements occurred to the west of Andros Island, an area which has the largest concentration of whitings, white sediment-laden bodies of water produced by photosynthetic cyanobacteria.

"Cyanobacteria need 10 times more iron than other photosynthesizers because they fix atmospheric nitrogen," said Swart, lead author of the study. "This process draws down the carbon dioxide and induces the precipitation of calcium carbonate, thus causing the whiting. The signature of atmospheric nitrogen, its isotopic ratio is left in the sediments."

Swart's team suggests that high concentrations of iron-rich dust blown across the Atlantic Ocean from the Sahara is responsible for the existence of the Great Bahama Bank, which has been built up over the last 100 million years from sedimentation of calcium carbonate. The dust particles blown into the Bahamas' waters and directly onto the islands provide the nutrients necessary to fuel cyanobacteria blooms, which in turn, produce carbonate whitings in the surrounding waters.

Persistent winds across Africa's 3.5-million square mile Sahara Desert lifts mineral-rich sand into the atmosphere where it travels the nearly 5,000-mile northwest journey towards the U.S. and Caribbean. The paper, titled "The fertilization of the Bahamas by Saharan dust: A trigger for carbonate precipitation?" was published in the early online edition of the journal Geology. The paper's authors include Swart, Amanda Oehlert, Greta Mackenzie, Gregor Eberli from the UM Rosenstiel School's Department of Marine Geosciences and John Reijmer of VU University Amsterdam in the Netherlands.


Story Source:

The above story is based on materials provided by University of Miami Rosenstiel School of Marine & Atmospheric Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. P. K. Swart, A. M. Oehlert, G. J. Mackenzie, G. P. Eberli, J. J. G. Reijmer. The fertilization of the Bahamas by Saharan dust: A trigger for carbonate precipitation? Geology, 2014; DOI: 10.1130/G35744.1

Cite This Page:

University of Miami Rosenstiel School of Marine & Atmospheric Science. "Saharan dust is key to formation of Bahamas' Great Bank, study finds." ScienceDaily. ScienceDaily, 24 July 2014. <www.sciencedaily.com/releases/2014/07/140724182933.htm>.
University of Miami Rosenstiel School of Marine & Atmospheric Science. (2014, July 24). Saharan dust is key to formation of Bahamas' Great Bank, study finds. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2014/07/140724182933.htm
University of Miami Rosenstiel School of Marine & Atmospheric Science. "Saharan dust is key to formation of Bahamas' Great Bank, study finds." ScienceDaily. www.sciencedaily.com/releases/2014/07/140724182933.htm (accessed September 30, 2014).

Share This



More Earth & Climate News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Balloon Descends to Bottom of Croatian Cave

Raw: Balloon Descends to Bottom of Croatian Cave

AP (Sep. 29, 2014) An Austrian balloon pilot has succeeded in taking a balloon deep underground, a feat which he believes is a world first. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Bodies Recovered from Japan Volcano Eruption

Bodies Recovered from Japan Volcano Eruption

AP (Sep. 29, 2014) Rescue crews finished recovering the remaining 27 bodies from atop Japan's Mount Ontake Monday. At least 31 people were killed Saturday in the mountain's first fatal volcanic event in modern history. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Raw: Japan's Mount Ontake Erupts

Raw: Japan's Mount Ontake Erupts

AP (Sep. 27, 2014) A volcano erupted in central Japan on Saturday, sending a large plume of ash high into the sky and prompting a warning to climbers and others to avoid the area. (Sept. 27) Video provided by AP
Powered by NewsLook.com
California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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