Our directory of things of interest

University Directory

Saharan dust fed Bahamas formation

  • Written by  Olivia Edward
  • Published in Deserts
Saharan dust fed Bahamas formation NASA
01 Sep
2014
Iron-rich Saharan dust played a major role in the formation of the Bahamian islands, providing the nutrients necessary for specialised bacteria to produce the island chain’s carbonate-based foundation, according to a new study published in Geology

Persistent winds across the Sahara lift sand into the atmosphere, causing it to travel towards the USA and the Caribbean. According to a team led by Peter Swart of the University of Miami, this dust is responsible for the existence of the Great Bahama Bank, which built up over the past 100 million years. The dust particles, the team contends, provided the nutrients necessary to fuel cyanobacteria blooms, which in turn, produced the calcium carbonate sediment that makes up the bank.

Swart and his team collected 270 seafloor samples along the Great Bahama Bank over a three-year period and then measured the concentrations of two trace elements characteristic of atmospheric dust – iron and manganese. They found the highest concentrations in samples collected to the west of Andros Island. This area has the largest concentration of so-called whitings – white sediment-laden bodies of water that are produced by photosynthetic cyanobacteria.

‘Cyanobacteria need ten times more iron than other photosynthesisers because they fix atmospheric nitrogen,’ said Swart. ‘This process draws down the carbon dioxide and induces the precipitation of calcium carbonate, thus causing the whiting.’

Related items

geo line break v3

Free eBooks - Geographical Newsletter

geo line break v3

EDUCATION PARTNERS

DurhamBath Spa600x200 Greenwich Aberystwythherts

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in PLACES...

Water

A new device, developed at ETH Zurich, could help communities…

Forests

A new initiative to save mangrove forests in the Dominican…

Deserts

The semi-autonomous Russian republic of Kalmykia sits at the forefront…

Cities

In Mogadishu, the troubled capital of Somalia, tentative moves towards…

Mountains

Researchers have predicted the birth of a new mountain range,…

Forests

Archaeological work around Lake Malawi suggests that humans manipulated the…

Water

Maida Bilal risked all to prevent contractors building a dam…

Places

Writer and photographer John Gilbey needed a cheap way of…

Water

An EU project has revealed the extent of river fragmentation…

Mapping

A new, double-sided world map projection seeks to minimise the…

Water

 Water scarcity is predicted to rise – two experts share…

Mountains

New collaborative research from the University of Oxford and the…

Places

Conceived during the late 1800s, Letchworth Garden City was the…

Places

Multiple failed attempts to build on a patch of land…

Deserts

New 'deep learning' technology is helping to identify trees in…

Places

The land around the Kinabatangan River in the state of…

Places

Highlights from the column that keeps you connected with the…

Places

At the end of a perplexing and thought-provoking year, we…

Places

The city of Mosul is slowly putting itself back together…