Hunga Tonga-Hunga Ha’apai is an underwater volcano off the coast of Tonga, just 62 kilometers (39 miles) northwest of the Tongan capital of Nuku’alofa. The volcano gets its name from the two small islands it’s nestled between, Hunga Tonga and Hunga Ha’apai, and is part of the highly active Tonga-Kermadec Islands volcanic arc.
The area, which is known to Tongans as the islands that “jump back and forth” from seismic activity, is also part of the highly volcanic Pacific Ring of Fire. It is thus believed that Hunga Tonga-Hunga Ha’apai is part of a cluster of 36 undersea volcanoes.
In March 2009, Hunga Tonga-Hunga Ha’apai erupted for several days, sending a violent stream of steam, rocks, and ash thousands of feet into the air. For days, huge columns of smoke and ash were seen rising from the Pacific Ocean.
Geologists confirmed that the eruption came from two volcanic vents, one located on Hunga Ha’apai, and another located 100 meters (330 feet) offshore. The two vents ejected so much debris, however, that they created a new landmass between them. Though the eruption wiped out all signs of wildlife on the original islet, the “new” island added hundreds of square meters to Hunga Ha’apai.