A wave as tall as a five-story building swelled, reared its head, and slammed back into the Southern Ocean on May 20, The Weather Channel reports. Scientists say it was one of the largest ever recorded in the Southern Hemisphere.

The Southern Ocean, also known as the Antarctic Ocean, surrounds the lowermost continent, mingling upward into the Atlantic, Pacific, and Indian Oceans. It’s a realm of strong, persistent westerly winds and “unlimited fetch” (a term defined as “an area of ocean surface over which the wind blows in a constant direction,” and not “cool.” Sorry, Gretchen). These extreme conditions combine to regularly roll up waves, but none like the 63-foot giant that crashed through over the weekend.

The wave activity was picked up by a buoy newly installed in the waters near Campbell Island, New Zealand.

"The buoy is performing extremely well so far," according to a statement by oceanographer Tom Durrant of MetOcean Solutions, the company that monitors the buoy. "Not only is it surviving these large waves, but it is making detailed recordings of extreme sea states in the Southern Ocean, a region rarely observed by in-situ instruments.”

Durant says understanding how the ocean rocks and rolls in extreme conditions can help scientists understand waves and the relationship between air and water.

He added, “This, in turn, will lead to improvements in the models used to simulate the waves, providing better forecasts, both for the Southern Ocean and for the wider region.”

[h/t The Weather Channel]