Novarupta, Volcanic formation in Katmai National Park and Preserve, Alaska, United States

Novarupta is a 90-metre-high, 360-metre-wide dome of rhyolite lava that plugged the vent of the 1912 eruption, located on a slope of Trident Volcano in Katmai National Park and Preserve, Alaska. The dome is a mound of dark grey and black broken rock and ash, with patches of snow on its slopes and near its rounded summit, rising from a barren plain.

The June 1912 eruption lasted 60 hours and ranks as the most powerful volcanic event of the 20th century worldwide. The explosion transformed the surrounding terrain into a plain of ash and formed what became known as the Valley of Ten Thousand Smokes.

The Alaska Natives living downwind of the 1912 ash cloud drew on traditional knowledge passed down from earlier eruptions to protect drinking water and food supplies. Villages that received the heaviest ash falls were abandoned and their inhabitants relocated.

Access requires a journey through remote wilderness with no road connections, typically by floatplane from King Salmon. Visits are possible from June through September when guided tours operate through the park.

The eruption formed a new volcano at a spot where no mountain existed before. The expelled material covered more than 100 square kilometers with a thick layer of hot ash and pumice.