The Hunga Tonga-Hunga Ha'apai — an underwater volcano located 40 miles (65km) north of Nuku'alofa, the capital of the Kingdom of Tonga — has erupted a couple of times over the past few decades. However, its January 15, 2022, explosion was like none other seen on Earth in over 30 years. The spectacular 13-mile-wide eruption, with a sonic boom heard 6,000 miles away in Alaska, spewed large plumes of ash and gases as high as 19 miles. The massive waves that followed triggered tsunami warnings in Peru, New Zealand, Japan, and the US West Coast.