Earth’s oceans are hiding deep secrets waiting to erupt. There are millions of volcanos underwater, each a potential island in the making.

If you’re searching for a big bang of the volcanic variety, stop limiting your search to the usual suspects like Kilimanjaro and Mauna Loa. Instead, pull on a wetsuit and take a dive underwater, where in places like the Pacific Ocean you’ll find thousands of active ‘submarine’ volcanoes. Just don’t expect to see the over-the-top eruptions common to above-ground volcanoes. Volcanologists think that because of the depths submarine volcanoes are often found at and the increased atmospheric pressure, it would be extremely rare you’d ever come across a fire and brimstone type of eruption.

Instead, scientists think that submarine volcanoes might be erupting in shorter bursts, but extended over longer periods of time. These cycles can last anywhere from two weeks to a slow and steady release of magma over the span of 100,000 years. Thanks to relatively recent technological advances that began in 1990, scientists have been able to sonically listen in on eruptions and track just when they happen.

Now these underwater volcanoes are being assessed to see just how much (or little) they might be contributing to global warming and climate change. Just like their dry land counterparts, submarine volcanoes spew carbon dioxide. In their case, these gases  get trapped in water but are eventually released to the atmosphere. These are ongoing studies still in the early stages of development, but they’re helping to unveil a new side of underwater volcanic activity that could only be guessed at before.

Story by Jay Moon