Geologic Background:
Prior to 1888, Ritter Island was a steep-sided
nearly circular island about 780 m high.
Historic Activity:
- Several historical explosive eruptions had been
recorded prior to 1888, when large-scale slope failure
destroyed the summit of the conical volcano, leaving an
arcuate 140-m-high island remnant with a steep
west-facing scarp. Devastating tsunamis were produced by
the collapse and swept the coast of Papua New Guinea and
offshore islands.
- Two minor post-collapse explosive eruptions, during
1972 and 1974, occurred offshore within the largely
submarine 3.5 x 4.5 km breached depression formed by the
collapse.
Recent Activity:
- Submarine eruption west of Ritter in October
1972.
- Seismic activity in October 1974
Data Sources:
|