Ambitle is a volcanic island

Volcano

2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 which, together with Babase, another volcanic island, is one of the two Feni Islands

Feni Islands

Feni Islands is an island group in Papua New Guinea, located east of New Ireland, at . It is a part of Bismarck Archipelago. Largest island of the group is Ambitle, other islands include Babase Island....

 in the Bismarck Archipelago

Bismarck Archipelago

The Bismarck Archipelago is a group of islands off the northeastern coast of New Guinea in the western Pacific Ocean and is part of the Islands Region of Papua New Guinea.-History:...

. The island is located within the Papua New Guinea

Papua New Guinea

Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...

's New Ireland Province, to the east of the island of New Ireland

New Ireland (island)

New Ireland is a large island in Papua New Guinea, approximately 7,404 km² in area. It is the largest island of the New Ireland Province, lying northeast of the island of New Britain. Both islands are part of the Bismarck Archipelago, named after Otto von Bismarck, and they are separated by...

.

Ambitle is a stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

, reaching 450 meters (1,476 feet) above sea level. It last erupted in about 350 BCE based on radiocarbon dating

Radiocarbon dating

Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...

. Its caldera

Caldera

A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

, 3 km or about 2 miles wide, contains thermal areas on its western side. Venting of hydrothermal water also occurs in coral reef

Coral reef

Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...

s to the west of this island.