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Underwater Volcanic Eruption
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Underwater Volcanic Eruption

July 27, 2010
Oceanographers discovered an undersea eruption nearly 2,500 meters beneath the surface of the Pacific Ocean as it happened in the spring of 2006.

The discovery was made by scientists aboard the research vessel (R/V) Knorr, while tracking the locations of 12 ocean-bottom seismometers designed to monitor earthquake activity on the East Pacific Rise tectonic plate boundary, south of the Gulf of California. When the researchers recovered only 4 of their 12 seismometers, they became suspicious that a lava flow might have covered or damaged them.

As seawater--heated by subsurface magma--jets out from cracks in the ocean crust, it rises, then spreads out in a cloud-like formation 200 to 250 meters above the seafloor. During the spring eruption, the cloud was detected four miles south of where active venting was documented. Rocks were dredged from the seafloor in one of the most active areas of venting. The surface of the basaltic rocks was glassy and iridescent, indicating very recent cooling of hot magma by contact with cold seawater.