Ritter Island

Ritter Island is a small volcanic remnant island off the coast of New Guinea in the Bismarck Sea. It is notable for a major volcanic sector collapse in the late 19th century that removed much of the original cone.

Today the island exists as a crescent-shaped remnant with submerged debris and a prominent submarine landslide deposit mapped by geologists. The event that reshaped the island generated a tsunami and is a key case study in volcanic flank collapse.

Ritter Island lies offshore in the Bismarck Sea region of Papua New Guinea, and the remnant is visited chiefly by scientific teams rather than general tourism.

• 1888 collapse: A catastrophic sector collapse in 1888 removed most of the island’s volcanic cone and produced a tsunami documented by contemporaries and later studies.

Ritter Island lies off the coast of Papua New Guinea’s Morobe Province. Access is by sea from nearby coastal towns such as Karkar or from Lae; local skippers and dive operators provide the only practical means of approach.

• Ritter Island isn't a typical tourist destination - plan visits with a diving operator familiar with the Bismarck Sea and the site's strong currents.
• Read accounts of the 1888 eruption/landslide beforehand: the island's collapse produced one of the Pacific's most infamous tsunamis and is of interest to geologists.