When we think of volcanoes, we typically picture the high, mountainous peaks, such as Mount Vesuvius and Krakatoa. However, there are actually more volcanoes below the water than above. In fact, almost 80% of the volcanic activity on Earth occurs underwater! These underwater volcanoes act as pressure valves, releasing heat and molten rock from underneath the ocean’s floor. According to scientists, one of these underwater volcanoes, the Axial Seamount, is set to erupt again any day now. Located 300 miles off the coast of Oregon in the Pacific Ocean, the eruption will likely not threaten the public. However, it may still have a considerable impact on the surrounding sea floor.

The Power of Underwater Volcanoes

The Axial Seamount is a mile-wide underwater volcano that lies 5,000 feet below the Pacific Ocean’s surface. The eruption of the Axial Seamount causes lava to pour out, redesigning the sea floor in the process, as it did in 1998, 2011, and 2015. When it last erupted in 2015, the surrounding ocean floor sank almost 8 feet, effectively reshaping the hydrothermal vent fields. According to scientists, there are now several signs that another eruption is imminent. They have observed considerable sea floor inflation in that area, in addition to an increase in seismic activity.

While they have not been able to point to any specific date, they believe it could happen very soon. Due to the buildup of magma near the surface, the volcano begins to swell over time. According to marine geophysicist William Wilcock, “Some researchers have hypothesised that the amount of inflation can predict when the volcano will erupt, and if they’re correct, it’s very exciting for us, because it has already inflated to the level that it reached before the last three eruptions.” In fact, the Axial Seamount has already inflated more than it had just before the last eruption in 2015.

However, the seismic activity is still relatively low when compared with the last eruption. At the moment, they are recording around 200 to 300 earthquakes every day. Some days, this number will spike to approximately 1,000 daily earthquakes due to the tides. Yet, in 2015, they were recording around 2,000 earthquakes per day for a couple of months before it erupted.

No Threat To Humans

 

While the eruption may potentially be powerful, it doesn’t pose any threat to human life. Whatever happens, the scientists are sure to learn something new. Underwater volcanoes are typically hard to observe, so each one is a learning experience, offering fresh insights to the researchers. What they do know is that the underwater volcano is currently “under a state of critical stress”. They will now wait to see if there is the expected increase in surrounding earthquakes that they have previously observed.

In these situations, the weight of the ocean presses down on the crust at high tide, but then decreases at low tide. When the weight decreases, the number of earthquakes increases. The scientists are interested to learn if these factors impact the chances of an eruption occurring due to additional stress on the magma chambers.

The eruption will also produce some interesting effects as the magma and cool ocean water collide on the sea floor. Pockets of seawater heat up and turn into steam when trapped beneath a lava flow. When the steam is released, it forms a bubble that cools rapidly and eventually collapses. This causes a loud implosion that the researchers can pick up using their hydrophones. With every new eruption recorded, the underwater volcanoes release more of their secrets to the scientists, expanding our understanding of the mechanisms that shape our world.