© MBARIThese delicate carbonate spires formed at an active vent site in the newly discovered Pescadero Basin hydrothermal field.
In spring 2015, MBARI researchers discovered a large, previously unknown field of hydrothermal vents in the Gulf of California, about 150 kilometers (100 miles) east of La Paz, Mexico. Lying more than 3,800 meters (12,500 feet) below the surface,
the Pescadero Basin vents are the deepest high-temperature hydrothermal vents ever observed in or around the Pacific Ocean. They are
also the only vents in the Pacific known to emit superheated fluids rich in both carbonate minerals and hydrocarbons. The vents have been colonized by dense communities of tubeworms and other animals unlike any other known vent communities in the in the eastern Pacific.
Like another vent field in the Gulf that MBARI discovered in 2012, the Pescadero Basin vents were initially identified in high-resolution sonar data collected by an autonomous underwater vehicle (AUV). MBARI's yellow, torpedo-shaped seafloor-mapping AUV spent two days flying about 50 meters above the bottom of the Basin, using sound beams to map the depth and shape of the seafloor.
The AUV team, led by MBARI engineer David Caress, pored over the detailed bathymetric map they created from the AUV data and saw a number of mounds and spires rising up from the seafloor. Data from the AUV also showed slightly warmer water over some of the spires, which implied that they might be active hydrothermal-vent chimneys. A team of geologists led by David Clague then used a tethered underwater robot, the remotely operated vehicle (ROV) Doc Ricketts, to dive down to the seafloor, fly around the vents, and collect video and samples of rocks and hot water spewing from the chimneys.
Reflecting on the discovery, Clague commented, 'Before the AUV survey of Pescadero Basin, all we knew was that this area was really deep and filled with sediment. I was hoping to find a few outcrops of lava on the seafloor. But we got lucky. The vent field was right on the edge of our survey area, along a fault at the western edge of the basin.'
The AUV and ROV dives showed that the new field extends for at least 400 meters (one quarter mile) along this fault. Within this area the researchers found at least three active hydrothermal chimneys up to 12 meters (40 feet) tall, as well as dozens of low mounds that are most likely collapsed chimneys.
© 2015 MBARIThis 3D map of the seafloor was generated using sonar data from MBARI's seafloor-mapping AUV. It shows several hydrothermal chimneys rising up to 12 meters (40 feet) above the floor of the Pescadero Basin.
Comment: Perhaps increased methane outgassing and undersea volcanic activity (it is estimated there are up to one million of these 'submarine volcanoes') are contributory factors to the "unprecedented warming occurring over the last 13 years"?
The significant increase of fish die off's and strange migratory behaviour of marine life could be considered other potential signs of such activity also.
As the number of volcanoes erupting right now is greater than the 20th century's YEARLY average, a comparable escalation in activity of their underwater counterparts seems logical.