Alaska’s Mount Redoubt erupted six times between Sunday night and Saturday morning, sending an ash cloud 9.5 miles (15 kilometers) into the air! The eruptions also caused small earthquakes and mudflows. The volcano could keep erupting for days… weeks… or even months!

Mount Redoubt wasn’t the only recent volcano eruption. An undersea volcano in Tonga also erupted last week. Tonga is an archipelago (group of islands) in the Pacific Ocean. The eruption has sent up ash, smoke, and steam. Underwater volcanoes can build islands as the magma builds up–that’s how the Hawaiian Islands were formed.

Read more about the Mount Redoubt eruptions and see pictures on National Geographic News.

Read about the Tonga eruption on National Geographic News.

See photos of volcanoes in the Photo Gallery!