>> NARRATOR: Scientists believe that 80% of all eruptive activity on Earth takes place in the ocean, yet only a handful of underwater eruptions have ever been documented. Scientists with the Vents Program at NOAA's Pacific Marine Environmental Lab, along with university partners, have figured out a way to find these needles in a haystack. Tectonic plate boundaries are home to a flurry of activity due to the stress of one plate coming into contact with another. Dr. Joe Resing and his colleagues traveled to the Northeast Lau Basin in 2008 where active subduction and seafloor spreading is occurring making it the perfect spot to hunt for activity. >> RESING: The first step in finding an erupting underwater volcano is to make detailed bathymetric maps of the area. The Mata volcano range is home to many volcanic-like structures with West Mata having a clearly defined conical top. >> NARRATOR: Located in over 9,000 feet of water, West Mata is 5,000 feet tall, comparable in size to the land volcano Stromboli off the north coast of Sicily. >> RESING: Next, we lower an instrument in the water that can see smoke-like particles produced by the volcano and collect water samples. These water samples are then analyzed for chemicals that are indicative of a possible eruption. >> NARRATOR: Scientists went back to West Mata in 2009 to try and capture an eruption on camera using the Remotely Operated Vehicle JASON. What Joe and his colleagues saw was beyond their wildest expectations. [Deep volcano rumbling] >> RESING: We observed molten lava flowing across the deep-ocean seafloor for the very first time giving us a firsthand look at the way ocean islands and submarine volcanoes are born. Shrimp were the only animals thriving in this acidic environment where some eruptive fluids were as acidic as battery acid. >> NARRATOR: Scientists returned to West Mata a year later and it was still erupting. The discovery of the West Mata volcano will continue to provide invaluable information on how heat and matter are transferred from the interior of the Earth to its surface and how life adapts to some of the harshest conditions on Earth. Where will the next active submarine volcano be found? Follow the Vents Program online to find out!