Scientists have uncovered clusters of volcanic vents towering above the seafloor in a region of deep-sea off the coast of Mexico. The so-called “black smoker” vents lie about 7,400 meters (7,900 feet) deep with chimneys reaching 23 meters (75 feet). These magma-powered hydrothermal vents are essentially fissures and cracks in the ocean floor that allow seawater to reach deep, superheated rocks, producing scalding jets of chemical-laden water.
Researchers from Monterey Bay Research Institute (MBARI) discovered these vent fields in late April, at the tail end of a three-month expedition to the Gulf of California that separates mainland Mexico from the Baja Peninsula. The vents lie near the tip of the peninsula along the Alarcón Rise, a seafloor spreading center, where tectonic forces are shoving magma up toward the seafloor along a volcanic steam, birthing fresh ocean crust and pushing two oceanic plates apart.
These maps show the location of the Alarcón Rise, a 50-kilometer-long (31-mile-long) spreading center at the mouth of the Gulf of California. Along ocean spreading ridges like the Alarcón Rise, the seafloor is splitting apart as lava wells up from underneath. (Credit: MBARI)
The team took samples of the animals living near the vents: tube worms that can grow to more than 5 feet (1.5 meters) long, clams up to 10 inches (25 centimeters) across, and other weird creatures that survive on the vents’ volcano-powered chemical soup. The researchers also measured temperatures as high as 300 degrees Celsius (572 degrees Fahrenheit), although there are indications the vent fluids could be hotter than 350 C (660 F).
These photos show a diverse community of organisms that inhabit the newly discovered hydrothermal vent fields. These communities do not depend upon sunlight, or photosynthesis. Instead, bacteria use the chemical-rich vent water as a source of energy, a process known as chemosynthesis. These chemosynthetic bacteria then support dense populations of worms, snails, crabs, clams, and fish. (Credit: MBARI)
Hydrothermal vents transport heat and chemicals into the ocean, providing an energy source that supports a robust community of deep-sea organisms, many of which are not found in any other ocean ecosystem. Knowing where and with what frequency hydrothermal vents occur is valuable information for scientists seeking to deepen our understanding of the biology, chemistry, and geology of the seafloor. MBARI’s seafloor-mapping AUV is helping oceanographers spend less time looking for, and more time looking at, these fascinating deep-sea phenomena.
The new sonar mapping technique offers great promise for tracking down other hydrothermal vents on the seafloor, which increasingly appear to be more plentiful in the world’s oceans than once thought.
Sonar-made map showing the hydrothermal vents, marked by a yellow circle, that can be clearly seen rising above the seafloor. (Credit: MBARI)
Source: Monterey Bay Research Institute (MBARI)
Featured image: Hot (550°F), mineral-rich water spews from the seafloor in the hydrothermal vent field discovered on April 28, 2012. The mineral-rich water from this “black smoker” looks like smoke because of the mineral particles that form the hot vent fluid contacts cold seawater. A white bacterial mat is seen on the surface of the chimney below the black smoker. Bacteria use the chemicals in the water as a source of energy. (Credit: MBARI)
August 30, 2011- INDONESIA - I originally had this information in today’s first post, but it likely deserves its own post, so here it is. Eruptions reader Martin pointed out an new report (Indonesian) from the volcanological survey in Indonesia, the PVBMG, that raises the alert level at one of Indonesia’s most famous volcanoes, Tambora. Now, many of you volcano enthusiastics would remember Tambora for 1815, when it produces one of the largest eruptions in the past few thousand years. This eruption threw enough material and aerosols into the atmosphere to cause significant global cooling, producing the “Year without a Summer” documented across the globe. What most people don’t know is that after the 1815 eruption, Tambora has erupted at least 3 known times, all in the scale of VEI 0-2 (rather than the VEI 7 of 1815). Why do I mention this? Well, with any news of increased seismicity and steam plumes at a volcano like Tambora, you can be sure the fear/panic-mongers will come out in full force. The PVBMG reports says that since April 2011, the volcano has seen intermittent swarms of earthquakes and now at the end of August, there seems to be an increase in these shallow, volcanic earthquakes along with the presence of tremor. Combine that in observations of steam plumes rising tens of meters over the edge of the caldera rim, then you might have the signs of impending activity – thus the elevation of the alert status from Level I to II. Now, what kind of activity might we expect? Most likely we would expect something small, akin to the VEI 0-2 eruptions in 1819, 1880 and 1967, which were mainly lava flows and domes confined to the caldera floor, and most definitely not another VEI 7 event like the 1815 eruption. So, an eruption at Tambora would definitely get a lot of people’s attention, but don’t expect it to bring about a summerless 2012. –
