Scientists find dome of ‘violent’ submarine volcano off the coast of Baja, California

December 14, 2012CALIFORNIAScientists have discovered one of the world’s weirdest volcanoes on the seafloor near the tip of Baja, Mexico. The petite dome — about 165 feet tall (50 meters) and 4,000 feet long by 1,640 feet wide (1,200 m by 500 m) — lies along the Alarcón Rise, a seafloor-spreading center. Tectonic forces are tearing the Earth’s crust apart at the spreading center, creating a long rift where magma oozes toward the surface, cools and forms new ocean crust. Circling the planet like baseball seams, seafloor-spreading centers (also called mid-ocean ridges) produce copious amounts of basalt, a low-silica content lava rock that makes up the ocean crust. But samples from the newly discovered volcano are strangely rhyolite lava, and have the highest silica content (up to 77 percent) of any rocks collected from a mid-ocean ridge, said Brian Dreyer, a geochemist at the University of California, Santa Cruz. The results were presented last week at the annual meeting of the American Geophysical Union. Researchers with the Monterey Bay Aquarium Research Institute (MBARI) discovered the volcano this spring, during a three-month expedition to the Gulf of California, the warm stretch of water that separates Baja from mainland Mexico. A remote-control vehicle explored the volcano, which is 7,800 feet (2,375 m) below the surface, and brought samples back to the ship. “When we picked up the rocks and got them back on the ship, we immediately noticed that they were very low density, and they were very light, glassy and gray. They were not the usual dark, black, shiny basalts,” Dreyer told OurAmazingPlanet. “So we immediately knew that something was unusual.” The volcano is primarily rhyolite and a silicic lava called dacite, said MBARI geologist Jennifer Paduan. “To find this along a mid-ocean ridge is a total surprise,” she told OurAmazingPlanet. Boulders and blocks the size of cars and small houses littered the steep slopes of the dome, the robot’s video camera showed. Of more concern is the evidence for explosive volcanism, which is typical of rhyolite volcanoes, Paduan said. “It’s only 100 kilometers [60 miles] from land. When the sun is setting, you can see Cabo,” she said. Both the Baja Peninsula and mainland Mexico near Alarcón Rise have cities and luxury resorts. The Gulf of California is also home to endangered sea life. Rhyolite lava carries more gas and volatiles (things that are likely to cause explosions) than basalt, and when magma meets water, it vaporizes instantly, driving an even more explosive eruption. “There’s definitely explosive deposits there, and that is of extreme concern, given that the ridge is so close to land and the tsunami potential of a big explosion there,” Paduan said. “We don’t know how explosive, and that is something we are definitely trying to figure out.” Rhyolites have been found on spreading centers, but only above hot spots, such as in Iceland and the Galapagos Islands, Dreyer said. Hot spots are plumes that bring magma to the surface from deep within Earth’s mantle. There is no hot spot under the Alarcón Rise, he said. Rhyolite lava typically occurs only on continents, such as in Mount St. Helen’s growing dome in Washington. One possible explanation for the bizarre composition of the Alarcón dome is that continental crust snuck into the molten rock below — the spreading center is young, and continental crust lies close by. But tests of different isotopes (versions of elements with differing numbers of neutrons in the cores) in the lava samples revealed no evidence of contamination by continental crust, Dreyer said. –OAP
About these ads
This entry was posted in Civilizations unraveling, Earth Changes, Earth Watch, Earthquake Omens?, High-risk potential hazard zone, Lithosphere collapse & fisssure, Magma Plume activity, Potential Earthchange hotspot, Seismic tremors, Signs of Magnetic Field weakening, Strange high tides & freak waves, Submarine Volcano, Time - Event Acceleration, Volcano Watch. Bookmark the permalink.

6 Responses to Scientists find dome of ‘violent’ submarine volcano off the coast of Baja, California

  1. Even though I’m not an expert in volcanic matters ,they all seem to come alive,as if connected by wire everywhere. I’ve been to a lot of dormant volcanoes ,climed up explored down,and you’d never think they would come back to life again. If it was me making the decisions ,I’d say you all move to prairie country. Life is becoming a scary thing nowadays,one minute you are driving peacefully,and the next,,,,,,you’ve been swallowed in a giant sinkhole. Be safe people!!!

  2. Darlene LaMar says:

    I’m thinking that maybe parts of California really will end up under the ocean by the time 2020 hits
    There’s just to much happening in that area

  3. musivick says:

    the presence of Rhyolite lava is a clear indication the normal conveyor process of the Mantle Plume has changed… & hotter Mantle from deeper has risen real fast…
    thats what’s happening all over the Globe…the Earth Core is in a strange condition and causing long dormant areas to get reactivated in years instead of decades or generations & hundred year timeframes as was the past history of such events

    • This finding is a significant scientific milestone in 1). how little we know about the planet and 2). that very dangerous explosive triggers may lie under the world’s oceans. If there is one, logic dictates, there are many more and we may have just found one of the triggers for an ocean anoxic event, when methane exploded or exsolved in the world’s oceans in the Permian extinction.

      Submarine rhyoltic volcanic eruptions + methyl hyrdrates = megadisaster

  4. Irene C says:

    Makes me wonder about the 6.3 earthquake that we had SSW of Avalon, California.

  5. JimQ says:

    Almost 8000 feet of water is a heck of a buffer. What concerns me is activity under Yellowstone. If that Baby starts talking we are Doomed as a nation and possibly a species. No one is publicy saying anything about gas emmisions or tilt of land mass anymore .

All comments are moderated. We reserve the right not to post any comment deemed defamatory, inappropriate, or spam.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s