The famous mini research submarine Alvin arrived in San Diego on Thursday at the end of a mission in which its tiny crew witnessed the aftermath of a volcanic eruption on the seafloor while traveling 8,200 feet deep in the Pacific Ocean.
The research vessel Atlantis brought Alvin to the dock that UC San Diego’s Scripps Institution of Oceanography operates in San Diego Bay. Scripps, whose scientists sometimes use the 3-person submersible, is helping service it.
The 23-foot-long sub, which explored the first known hydrothermal vent a half century ago and later surveyed the wreckage of the RMS Titanic, is based at the Woods Hole Oceanographic Institution on Cape Cod in Massachusetts.
Last month, Alvin made a series of dives on the East Pacific Rise far to the west of Costa Rica to study one of the most active hydrothermal vent seafloor areas in the world.
On April 28, the Alvin team witnessed a rich community of tubeworms, mussels and other animals around the vents. When they returned to the area the next day, WHOI said, they found it barren and the water hazy — and they saw flashes of molten lava.
They were seeing the aftermath of a volcanic eruption.
The research team also noticed that the water temperature was slightly higher, which led them to return to the surface to avoid potential trouble.
“When we saw an orange shimmering glow in some of the cracks, it confirmed that a volcanic eruption had taken place and was still actually underway,” Alvin pilot Kaitlyn Beardshear said in a statement.
Remaining dives aboard Alvin were cancelled. But scientists aboard the mother ship Atlantis were able to take readings that helped explained the phenomenon the sub had encountered.
