Ritter Island

Ritter Island
Elevation 140 m (460 ft)
Prominence 140 m (460 ft)
Location
Location Papua New Guinea
Coordinates 5°31′S 148°07′E / 5.517°S 148.117°E
Geology
Type Stratovolcano
Last eruption May 2007

Ritter Island is a small crescent-shaped volcanic island 100 kilometres northeast of New Guinea, situated between Umboi Island and Sakar Island.

There are several recorded eruptions of this basaltic-andesitic stratovolcano prior to a spectacular lateral collapse which took place in 1888. Before that event, it was a circular conical island about 780 metres high.[1] At about 5:30 am local time on 31 March 1888 a large portion of the island, containing perhaps 5 km3 of material slid into the sea during a relatively minor, possibly VEI 2,[2] phreatic eruption. Eyewitnesses at Finschhafen, 100 km to the South, heard explosions and observed an almost imperceptible ash fall.[3] Tsunamis 12–15 metres high were generated by the collapse and devastated nearby islands and the adjacent New Guinea coast killing around 3000 people.[4]

The collapse left a 140 metre high 1900 metre long crescent-shaped island with a steep west-facing enscarpment. At least two small eruptions have occurred offshore since 1888, one in 1972 and another in 1974, which have resulted in the construction of a small submarine edifice within the collapse scar.[3]

See also

References

  1. ↑ "Ritter Island". Global Volcanism Program. Smithsonian Institution. Retrieved 2009-04-28.
  2. ↑ "Ritter Island - Eruptive History". Global Volcanism Program. Smithsonian Institution. Retrieved 2009-04-28.
  3. ↑ 3.0 3.1 Ward, S.N. and Day, S. (2003). "Ritter Island Volcano—lateral collapse and the tsunami of 1888" (PDF). Geophysical Journal International 154 (3): 891–902. Bibcode:2003GeoJI.154..891W. doi:10.1046/j.1365-246X.2003.02016.x. Retrieved 2007-06-11.
  4. ↑ Ritter Island at Volcano World