They are some of the most violent events on the planet , throwing out millions of tonnes of gas , ash and molten rock with each eruption . Yet the majority of the world ’ s volcanoes are found deep underwater where immense water pressure does weird things to the lava that bubbles out of them . Now scientists have finally been able to record one of these eruptions as it happens to discover the sound it makes - and they are surprisingly quiet for such a violent event . Scroll down to watch and listen to an underwater volcano erupting . The majority of the world ’ s volcanoes are found deep underwater and now scientists have been able to record one of these eruptions as it happens to discover the sound it makes . The bubbling lava erupting from the volcanic vent Hades ( above ) produced a distinctive acoustic signature . Rather than the explosive roar emitted by their cousins on land , underwater volcanoes give off a muted thrum instead . However , the research could allow scientists to monitor undersea volcanoes far more effectively than they have before . Volcanoes lurking hidden under the world 's oceans may play a far greater role in climate change than previously though . Scientists found that underwater volcanoes , which were long assumed to ooze lava at relatively steady rates , in fact erupt in pulses . A new study has shown that these submarine eruptions follow regular cycles that can range from just a couple of weeks to 100,000 years . The researchers claim these eruptions appear to be linked to changes in the Earth 's orbit that occur over time . Surprisingly the researchers also found that these eruptions also appear to be clustered during the first six months of each year . The findings may now mean that models predicting how human activity will change the climate will need to be adjusted . Volcanic eruptions are known to throw huge amounts of gas into the atmosphere , including carbon dioxide that are thought to increase global warming . However , volcanoes also release aerosol gases that are now known to reduce global warming by creating a reflective barrier against the sun . Using their unique sound signature , researchers will be able to detect different types of eruptions and record the gases being released far more accurately . Bob Dziak , an oceanographer at the National Oceanic and Atmospheric Administration 's Pacific Marine Environmental Laboratory in Newport , Oregon who led the research , said : ‘ Detecting seafloor volcanism is important because it is a very significant process in terms of chemical impacts on the ocean and natural hazards . ‘ Even though roughly 70 per cent of Earth ’ s volcanic activity occurs under the water , it has remained largely unobserved . ‘ So , the more of these events that we can detect remotely using acoustics , the more we can understand Earth ’ s processes and how the planet works. ’ Underwater volcanoes are known to be widespread on the floor of the world 's oceans at joins in the tectonic plates . Most are located in the deep ocean , where their activity can be difficult to measure , although some in shallow water can erupt with enough lava to create new islands . Others erupt with explosive results . A recent study found that emissions from underwater volcanoes may play a far greater role in influencing the climate than had previously been believed . Rather than oozing lava at relatively steady rates , they in fact erupt in pulses that follow regular cycles ranging from just a couple of weeks to 100,000 years . In the latest study , published in the journal Geophysical Research Letters , the scientists used an underwater vehicle to visit the West Mata Volcano , 3,937 feet ( 1,200 metres ) below the surface of the Pacific Ocean near Samoa . Eruptions from underwater volcanoes can sometimes form new islands like this one off the coast of Japan . A recent study found that emissions from underwater volcanoes may play a far greater role in influencing the climate than had previously been believed . They found different eruptions were occurring at two of the volcano ’ s vents – nicknamed Hades and Prometheus . Hades produced large lava bubbles that were released slowly , while Prometheus gave off explosive releases of tiny gas bubbles . They managed to film the eruptions as they happened and using hydrophones , recorded the sound they produced . They then analysed the acoustic signatures produced by each explosion , showing they are different . The graph above shows the acoustic signature as lava bubbles from Hades volcano ( marked by red arrows ) Scientists have struggled to study underwater volcanoes like the one above as they are hard to spot erupting . Using their unique sound signature , researchers will now be able to detect different types of eruptions and record the gases being released far more accurately . This video of Mount Tavurvur erupting on 29 August 2014 shows what volcanoes above ground sound like .
Geologists used undersea vehicles to record one underwater volcanic vents - called Hades and Prometheus - as they erupted near Samoa . Scientists found the acoustic signatures of the eruptions were different . They hope to use sound to monitor underwater eruptions as they happen .