A newly discovered volcano rumbling beneath nearly a mile of ice in Antarctica will almost certainly erupt at some point in the future, according to a new study. Such an event could accelerate the flow of ice into the sea and push up the already rising global sea levels.

When the volcano will blow is unknown, “but it is quite likely” to happen, Amanda Lough, a graduate student in seismology at Washington University in St. Louis, Mo., told NBC News.