The 2009 Tonga undersea volcanic eruption began on March 16, 2009, near the island of Hunga Tonga, approximately 11 kilometres (6.8 mi) from the Tongan capital of Tongatapu. The volcano is in a highly active volcanic region that represents a portion of the Pacific Ring of Fire. It is estimated that there are up to 36 undersea volcanoes clustered together in the area.