The 40,000 mile long volcano
by William J. Broad
Jan 12, 2016
New York Times
Picture a volcano. Now imagine that its main vent extends in a line. Now imagine that this line is so long that it runs for more than 40,000 miles through the dark recesses of all the world’s oceans, girding the globe like the seams of a baseball.
Welcome to one of the planet’s most obscure but important features, known rather prosaically as the midocean ridges. Though long enough to circle the moon more than six times, they receive little notice because they lie hidden in pitch darkness. Oceanographers stumbled on their volcanic nature in 1973. Ever since, costly expeditions have slowly explored the undersea world, which typically lies more than a mile down.
The results can make the visions of Jules Verne seem rather tame.
The ridges feature long rift valleys and, down their middles, giant fields of gushing hot springs that shed tons of minerals into icy seawater, slowly building eerie mounds and towers that can be rich in metals like gold and silver. One knobby tower in the Pacific Ocean, nicknamed Godzilla, grew 15 stories high. Thickets of snakelike tubeworms and other bizarre creatures often blanket the hot features, as do hungry prowlers such as spider crabs.
The riot of life coexists with springs hot enough to melt lead or the plastic windows of mini submarines. With extreme care, humans and robots have measured temperatures as high as 780 degrees.
More to the point, there is now a two part underwater observatory along the Juan De Fuca Ridge, off the west coast of the Americas, keeping a continue eye on what's going on, and as usual when you stare at places you haven't been before long enough, getting QUITE an eyefull, and ear full and... Just go look at the link. OK, here's a quote from the part about the observatory:
It sits atop the Juan de Fuca Ridge. The volcanic spreading center — more than 300 miles long — lies in a slanted line off the West Coast, from British Columbia to Oregon. The observatory is divided into two parts. Canada operates the northern one and the United States the southern one, part of a larger program known as the Ocean Observatories Initiative.
All told, it cost roughly $500 million — far less than the next generation of optical telescopes under construction around the globe. The National Science Foundation, the federal government’s big funder of basic science, paid for the American part.
Together, the two sites feature more than 1,000 miles of cables, dozens of junction boxes and hundreds of sensors.
Instruments on the seabed include tilt meters, cameras, seismometers, temperature gauges, hydrophones, chemical probes, pressure sensors and fluid samplers. Also, mobile platforms crawl up and down long moorings to take readings higher in the water column. The observatory’s main cables run ashore at Port Alberni, on Vancouver Island, and Pacific City, Ore.
“We have the most advanced cabled observatory on any volcano in the world’s oceans,” said Deborah S. Kelley, a scientist at the University of Washington who directs the American segment. “There’ll be lots of discoveries.