– Scientists identify thousands of previously unknown seamounts (volcanoes) (Ice Age Now, Oct 6, 2014):
The number of seamounts quadruples, soaring from around 5,000 to about 20,000
A new topographic map of Earth’s ocean floor reveals thousands of towering volcanoes and other never-before-seen features once hidden beneath miles of water and thick sediment, says this article in Live Science.
The world’s volcano count jumped tremendously thanks to the new map. The number of seamounts soared from around 5,000 to about 20,000, said lead study author David Sandwell, a marine geophysicist at the Scripps Institution of Oceanography in La Jolla, California.
Seamounts are small, conical volcanoes that are usually inactive or extinct. The map, released on Oct 2, captures all seamounts more than 0.9 miles (1.5 kilometers) tall.
“If we can map out (the seamounts) complete distribution, then we can understand how they grow and evolve and so on,” said Sandwell.
80 percent of the ocean floor has never been charted
Most of the new ridges, faults and volcanoes had remained undiscovered because 80 percent of the ocean floor has never been charted by ships.
In fact, even today the surface of Mars has been detailed more clearly than the ocean’s watery depths.
The seafloor topography comes from a gravity model of the ocean, which is in turn based on altimetry from the Jason-1 and Cryosat-2 satellites.
The ocean surface has subtle highs and lows that mimic both seafloor topography and Earth’s gravity field.
Thanks to Thomas McHart, Ronald Baker, Tim Kieler, Laurel and George Martinez for this link
“Thousands of undersea volcanoes just as you predicted,” says Ronald. “With the recent global volcanic uptick what do bet many are currently active. Thanks for all your hard work. Your insight has helped so many prepare for what coming. God bless you.”