This is the first structure of this type identified at this location

Jul 26, 2012 11:54 GMT  ·  By

Investigators at the University of California in San Diego's (UCSD) Scripps Institution of Oceanography (SIO) say that one of their latest surveys indicates the presence of a rather large methane seep off the coasts of San Diego.

This is the first time such a structure has been identified at this location, the experts add. The seafloor mound is roughly the size of a two-story building, and exceeds the area of a city block. Its role is to vent methane from beneath the bottom of the ocean into the water above.

The announcement was made on July 25. SIO scientists say that the hydrocarbon is responsible for producing the underwater landscape feature. The team made the discovery after analyzing a series of samples collected from 3,400 feet (1,036 meters) under the surface, Our Amazing Planet reports.

Scientists say that they identified a number of weird worms and clams, whose main source of food appeared to be certain species of symbiotic bacteria. The microorganisms in turn feed off methane.

According to oceanographers, seeps such as this one are very important for the deep-sea ecosystem. Methane-eating bacteria represent the basis of a very complex food web, which has ramifications beyond the area immediately around the vent.

“These chemosynthetic ecosystems are considered 'hot spots' of life on the seafloor in an otherwise desert-like landscape. New forms of life are continuously being discovered in these environments,” explains SIO biological oceanography graduate student and expedition member, Alexis Pasulka.

According to the maps the team provided, the methane seep is located approximately 20 miles (32 kilometers) west of Del Mar, California, right atop the San Diego Trough Fault zone.

Given the tremendous potential that methane has for warming the atmosphere – about 300 times higher than that of carbon dioxide – studying methane seeps and how they affect the air around us is critical for simulating the future evolution of climate change.

In addition to the ocean floor, there are several other important methane sources, including human activity. Perhaps the most dangerous source, and arguably the largest, is the Arctic permafrost.

If all methane in these soils were released, the planetary atmosphere would be thrown into disarray, and global warming would become irreversible many times over.