Mapping the ocean floor: Satellite data reveals uncharted mountains buried a mile beneath the sea bed

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Mapping the ocean floor: Satellite data reveals uncharted mountains buried a mile beneath the sea bed

Researchers combined satellite data with a computer model
From this, they were able to plot the locations of earthquakes
This, in turn, provided clues about the location of tectonic plates
Images and data used to map spreading ridges, seamounts and faults
Around 80% of the ocean floor remains unmapped or buried by sediment
This map is the most detailed look at the underwater landscape to date
By VICTORIA WOOLLASTON FOR MAILONLINE
Source: www.dailymail.co.uk

Using the latest data from satellites, scientists have uncovered uncharted features lying along the seafloor.
Until now, the depths of the oceans have been the least explored parts of our planet – and 80 per cent of it remains unmapped.
But, by using data from Nasa and the European Space Agency, geophysicists have been able to build the most detailed map of underwater ridges, trenches and plateaus to date.
Using data from Nasa and the European Space Agency satellites, geophysicists have been able to build the most detailed map of underwater ridges, trenches and plateaus to date. Depths over seamounts, including Reed Bank and Palawan, in the South China Sea are pictured

Using data from Nasa and the European Space Agency satellites, geophysicists have been able to build the most detailed map of underwater ridges, trenches and plateaus to date. Depths over seamounts, including Reed Bank and Palawan, in the South China Sea are pictured
The satellite images allowed them to peer through mile-thick layers of sediment to unveil the features on the sea floor.
It also provided new clues about the formation of the continents, and is said to be twice as accurate as a previous version produced almost twenty years ago.

The map, described in the journal Science, shows the mountains, or ‘seamounts,’ extending more than half a mile (1km) along the ocean bed.
Lead researcher, geophysicist Professor David Sandwell from the University of California, San Diego, said: ‘The kinds of things you can see very clearly now are abyssal hills, which are the most common land form on the planet.’
MAPPING THE OCEAN FLOOR
Satellites fitted with altimeters send pulses to the ocean’s surface – which bulge outward and inward to mimic the topography of the ocean floor.
The sensors then record the response, or gravity signal, which can reveal buried tectonic structures.
David Sandwell and his colleagues collected their measurements from two of four satellites currently equipped with high-resolution altimeters, CryoSat-2 and Jason-1.
They then combined this data with a computer program to build a marine gravity model twice as accurate as existing versions.
Last month, the Australian Transport Safety Bureau released 3D models of a ‘priority area’ in the Indian Ocean, as part of the search for missing plane MH370.
In the images, huge mountains, deep trenches and dormant volcanoes are seen strewn across the search area.
Similarly, canyons, lakes and mountains were revealed in the most detailed maps ever made of the hidden world beneath the polar regions.
Surveys of the Antarctic and Arctic revealed features buried under the ice including a ‘mega canyon’ in Greenland – bigger even than the Grand Canyon in the US.
And data from surveys of the regions has revealed the extent to which Arctic sea ice is gradually decreasing – and how long it might take to disappear.
In many parts of the ocean, including the region of the Indian Ocean where the Malaysian aircraft MH370 was lost this year, scientists don’t know much about seafloor tectonics.
Satellites fitted with altimeters send pulses to the ocean’s surface – which bulge outward and inward to mimic the topography of the ocean floor.
The sensors then record the response, or gravity signal, which can reveal buried tectonic structures.
To date, the resolution of these images has been limited by the number of available measurements.
David Sandwell and his colleagues collected their measurements from two of four satellites currently equipped with high-resolution altimeters, CryoSat-2 and Jason-1.
They then combined this data with a computer program to build a marine gravity model twice as accurate as existing versions.
Previously unseen features include newly exposed continental connections across South America and Africa, and new evidence for seafloor spreading ridges at the Gulf of Mexico that were active 150 million years ago.
These connections are buried by mile-thick (1.6km) layers of sediment.
The rifts, ridges and trenches of the ocean floor are shaped by the slipping and sliding of massive tectonic plates.
Red dots on the images, created by the marine gravity model of the North Atlantic, revealed the locations of earthquakes with magnitudes higher than 5.5.
From these dots, the researchers were able to highlight the location of the tectonic boundaries, spreading ridges and transform faults.
This gravity information also shows the details of the plate tectonic history of the rifting of these continents, including the fracture zones that are currently buried by sediment.
Another image, which recorded the vertical gravity gradient (VGG) model of the Southwest Indian Ridge, shows the slowest spreading ridge on the Earth.
It has large fracture zone signatures that record the rifting and spreading between Africa and Antarctica…….MORE HERE

 

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