Immense rivers that dwarf the Thames have been found at the bottom of the ocean by British scientists.
Like those on land, the submarine waterways carve out channels, tributaries, flood plains, rapids and even waterfalls.
One river, discovered underneath the Black Sea, is up to 115ft deep in places and more than half a mile wide.
If found on land, scientists estimate the so-far unnamed waterway would be the world's sixth largest river in terms of the amount of water flowing through it.
The flow – carrying highly salty water and sediment - is 350 times greater than the Thames, according to a Leeds University team who used a robotic submarine to scan the seabed near Turkey.
The undersea river - the only active one to have been found so far - stems from salty water spilling through the Bosphorus Strait from the Mediterranean into the Black Sea, where the water has a lower salt content.
This causes the dense water from the Mediterranean to flow like a river along the sea bed, carving a channel and deep banks.
The discovery could help explain how life manages to survive in the deep ocean far out to sea away from the nutrient rich waters that are found close to land, as the rivers carry sediment and nutrients with them.
Dr Dan Parsons, who led a team from the university's school of earth and environment, told the Sunday Telegraph: ‘The water in the channels is denser than the surrounding seawater because it has higher salinity and is carrying so much sediment.
‘It flows down the sea shelf and out into the abyssal plain much like a river on land.
The abyssal plains of our oceans are like the deserts of the marine world, but these channels can deliver nutrients and ingredients needed for life out over these deserts.
‘This means they could be vitally important, like arteries providing life to the deep ocean.
‘The key difference we found from terrestrial rivers was that as the flow goes round the bend, the water spirals in the opposite way to rivers on land.’
No comments:
Post a Comment