Scientific activity near deep sea vents may not be as harmful to some of their unique fauna as previously feared. Recently, researchers found lights used to illuminate the vents for study were blinding some Rimicaris exoculata shrimp. But new research shows that potential eye damage is not affecting shrimp numbers, and scientific expeditions pose no immediate conservation threat.
An International Team is to Honour the 30th Anniversary of the Deep-Sea Vent Discovery in Galápagos
Scientists first discovered volcanic hot vents surrounded by bizarre animals thriving in total darknesswithout energy from the sunat the bottom of the Pacific Ocean in 1977. At the end of June an international team of scientists, including many of the original explorers, will honour the 30th anniversary of the landmark discovery at a special meeting and public event in the Galápagos Islands, located just south of the discovery site.
A new "black smoker" -- an undersea mineral chimney emitting hot, iron-darkened water that attracts unusual marine life -- has been discovered at about 8,500 feet underwater by an expedition currently exploring a section of volcanic ridge along the Pacific Ocean floor off Costa Rica. Expedition leaders from Duke University; the Universities of New Hampshire, South Carolina and Florida; and the Woods Hole Oceanographic Institution (WHOI) in Massachusetts have named their discovery the Medusa hydrothermal vent field. The researchers are working aboard WHOI's research vessel Atlantis, and the expedition is funded by the National Science Foundation.
Scientists have found one of the largest fields of seafloor vents gushing super-hot, mineral-rich fluids on a mid-ocean ridge that, until now, remained elusive to the ten-year hunt to find them.
"The discovery of the first active vents ever found on an ultraslow-spreading ridge is a significant milestone event" - Jian Lin, leader of a team of Woods Hole Oceanographic Institution (WHOI) scientists who participated in a Chinese expedition to the remote Southwest Indian Ridge in the Indian Ocean in February and March.
Since deep-sea hydrothermal vents were first discovered 30 years ago in the Pacific Ocean, scientists have studied them all along the Mid-Ocean Ridge, a 40,000-mile-long mountain range that zigzags through the middle of the worlds ocean basins like a giant zipper. The ridge marks the area where the Earths giant tectonic plates spreads apart and new ocean crust forms from hot lava rising from deep within Earths mantle.
Most studies of the chimney-like vent structures have taken place along ridges in the fast-spreading East Pacific Rise (100 to 200 millimetres per year) and the slow-spreading Mid-Atlantic Ridge (20 to 40 millimetres per year). Only in recent years have scientists explored ultraslow-spreading ridges (less than 20 millimetres per year) in the Arctic and Indian Oceansremote areas tough to get to, and therefore the least studied. Scientists initially thought ultraslow-spreading ridges would be too cold to host large hot vents. But in the past decade, some scientists began to hypothesise that the slower a ridge spreads, the fewer vents it would havebut the bigger the vent fields would be.
"This cruise confirmed that hypothesis. People have been looking for active hot vents on ultraslow ridges for more than 10 years" - Jian Lin, a marine geophysicist and U.S. Coordinator of the 20-day expedition aboard the Chinese research vessel Dayang 1.
After years of results that repeatedly dogged him, University of Oregon geologist Douglas R. Toomey decided to follow the trail of data surfacing from the Pacific Ocean. In doing so, he and his collaborators may have altered long-held assumptions involving plate tectonics on the ocean floor. Reporting in the March 22 issue of Nature, Toomey and co-authors from four other institutions propose that, one, the flow in the Earth's mantle is rotated beneath the East Pacific Rise, causing the plate boundary to change orientation with time. Secondly, they argue that deep-sea hydrothermal vents frequently form above volcanoes where upwelling of the mantle and spreading of the plates are aligned. Surprisingly, Toomey added, the amount of magma produced by volcanoes under both aligned and non-aligned mantle-plate regions is relatively equal, but that magma only in aligned sections regularly breaches the crust. When the volcanic plumbing between the mantle and crust is not aligned, magma cools and volatiles are lost as the magma moves laterally, he said. Most of the magma then remains under the sea floor.
Scientists studying hydrothermal vents, those underwater geysers that are home to bizarre geological structures and unique marine species, have discovered something all too familiar: pollution.
A University of Florida geologist is among a team of geologists that is the first to observe “anthropogenic influence” in hydrothermal deposits, according to an article in the June issue of the journal Marine Geology. Examining deposits retrieved from the site of an underwater volcano near Italy, they discovered lead that did not come from the underlying rocks or from any possible natural source in the nearby region or anywhere in Europe.
Instead, they traced the lead to an Australian lead mine thousands of miles away.