Taxonomy term

In early February 1977, as scientists aboard the research vessel (R/V) Knorr made their way across the Pacific waters off the northwest coast of South America, they had reason to suspect their expedition might find the success that had eluded others. Previous missions had identified their destination — a site on the ocean surface about 330 kilometers northeast of the Galápagos Islands, below which two tectonic plates rift apart — as a promising location from which to search for their intended target. Once there, the researchers would deploy a variety of tools, including manned and unmanned submersibles, to the ocean bottom in the hopes of directly spotting hydrothermal vents.

Just beyond San Francisco’s Golden Gate Bridge is a shipwreck graveyard where as many as 300 vessels lie in silty underwater repose. A team of NOAA researchers conducting a two-year study to identify and map the long-forgotten ships in the Gulf of the Farallones National Marine Sanctuary and the adjacent Golden Gate National Recreation Area has announced the discovery of three wrecks: the 1863 wreck of the clipper ship Noonday, the 1910 shipwreck SS Selja and an unidentified early steam tugboat wreck tagged the “mystery wreck” — all now obscured by mud and silt on the ocean floor.
 

The release of methane from seafloor sediments may have a significant influence on global climate, but the ubiquity and stability of such pockets is not well understood. Now the discovery of hundreds of methane seeps on the seafloor along the U.S. East Coast suggests that such reservoirs may be more common along passive margins than previously thought. The easily accessible region may prove to be an ideal natural laboratory for studying how such seafloor methane may influence water temperatures and ultimately climate.

Pockmarked plankton shells and dead coral are becoming the hallmark images of ocean acidification. But this isn’t the first time seawater has dropped on the pH scale. Based on models of seawater chemistry, the ocean acidity during the Paleocene-Eocene Thermal Maximum (PETM), beginning about 56 million years ago, is the closest-known analog to today. Now, researchers using boron proxies preserved in microfossils to reconstruct surface-ocean chemistry suggest that acidification was more extensive and lasted longer than previously thought, although the PETM conditions still don’t outpace the current rate of ocean acidification.