Ritter Island

Infobox Mountain
Name= Ritter Island
Photo=
Caption=
Elevation= Convert|140|m|ft|-1|abbr=on
Location=Papua New Guinea
Range=
Prominence = Convert|140|m|ft|-1|abbr=on
Coordinates = coord|5|31|S|148|07|E|region:PG_type:isle
Topographic

Type=Stratovolcano
Age=
Last eruption= 2006
First ascent=
Easiest route=

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 meters high. [VNUM|1=0501-07=|2=Ritter Island] 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, [cite web | title=Ritter Island - Eruptive History | url=http://www.volcano.si.edu/world/volcano.cfm?vnum=0501-07=&volpage=erupt | accessdate=2007-06-11 | work = Global Volcanism Program | publisher = Smithsonian Institution] phreatic eruption. Eyewitnesses at Finschhafen, 100 km to the South, heard explosions and observed an almost imperceptible ash fall. cite journal | author = Ward, S.N. and Day, S. | title = Ritter Island Volcano—lateral collapse and the tsunami of 1888 | journal = Geophysical Journal International | volume = 154 | pages= 891–902 | year=2003 | url = http://www.es.ucsc.edu/~ward/papers/gji_Ritter_final.pdf | accessdate=2007-06-11 | doi = 10.1046/j.1365-246X.2003.02016.x|format=PDF] Tsunamis 12-15 metres high were generated by the collapse and devastated nearby islands and the adjacent New Guinea coast killing around 3000 people. [ [http://volcano.und.edu/vwdocs/volc_images/southeast_asia/group.html Ritter Island at Volcano World] ]

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.cite journal | author = Ward, S.N. and Day, S. | title = Ritter Island Volcano—lateral collapse and the tsunami of 1888 | journal = Geophysical Journal International |volume = 154 | pages= 891–902 | year=2003 url = http://www.es.ucsc.edu/~ward/papers/gji_Ritter_final.pdf | accessdate=2007-06-11 | doi = 10.1046/j.1365-246X.2003.02016.x|format=PDF]

References