An undersea volcano has erupted off the coast of Oregon, spewing forth a layer of lava more than 12 feet (4 meters) thick in some places, and opening up deep vents that belch forth a cloudy stew of hot water and microbes from deep inside the Earth.
Photograph by Patrick McFeeley, National Geographic
Updated May 27, 2011 (First posted May 26, 2011)
Scientists say they’ve found solid evidence of a giant mass of hot rock under the seafloor in the region. But it’s not a plume running straight from the core to the surface—and it’s hundreds of miles west of the nearest Hawaiian island.
Until now, the researchers say, good seismic data on the region has been scarce, so it was tough to question the Read more…
In 1993, marine geophysicists aboard the research vessel Melville discovered 1,133 previously unmapped underwater volcanoes off the coast of Easter Island. Though some of the newly discovered volcanoes rose as much as one-and-a-half miles above the seafloor, their summits still remained half a mile below the water’s surface- all this in a comparatively small area of only 55,000 square miles, about the size of New York State. The geophysicists had increased the known supply of underwater volcanoes by more than ten percent just in a matter of months. That was 1993. Today, scientists estimate that there are more than three million underwater volcanoes. That’s a three followed by six zeroes! In 2007, oceanographers Hillier and Watts surveyed 201,055 submarine volcanoes. “From this they concluded an astounding total of 3,477,403 submarine volcanoes must reasonably exist worldwide,” said this article by John O’Sullivan. Hillier and Watts “based this finding on the earlier and well-respected observations of Earth and Planetary Sciences specialist, Batiza (1982) who found that at least 4 per cent of seamounts are active volcanoes.” According to Batiza’s survey, the Pacific mid-plate alone contains an incredible 22,000 to 55,000 underwater volcanoes, with at least 2,000 of them considered active. Thinking Read more…
Nearly half a mile of rock retrieved from beneath the seafloor is yielding new clues about how underwater volcanoes are created and whether the underlying hot spots of molten rock that lead to their formation have moved over time.
Geoscientists have just completed an expedition, part of the Integrated Ocean Drilling Program (IODP), to a string of underwater volcanoes, or seamounts, in the Pacific Ocean known as the Louisville Seamount Trail.
There they collected samples of ocean floor sediments, lava flows and other volcanic eruption materials to piece together the Read more…