Ioto volcano (Japan) - Smithsonian / USGS Weekly Volcanic Activity Report for 19 September-25 September 2001 (New Activity / Unrest)
At 1015 on 21 September a submarine eruption began off of the SE coast of Iwo-jima, an island inhabited by U.S. and Japanese military personnel approximately 1,300 km S of Tokyo. The eruption was preceded by isolated and continuous tremor beginning on the evening of 20 September.
mer., 19 sept. 2001, 06:0006:00 AM | AUTEUR : VN
Visible evidence of the eruption consisted of seawater gushing several meters above sea level near the island's coast and an area of discolored seawater extending 300-400 m in length. During 1000-1100 approximately 30 earthquakes occurred in the active area; the typical rate is one or two earthquakes per hour. The climax of the eruption occurred during 1200-1500.
At about 1300 water gushed several ten's of meters above sea level and steam rose to 100-300 m above the sea. JMA personnel observed seawater rising intermittently during 1515-1715 at two points 50 m apart and 150-200 m from the island's SE coast. The temperatures at these points were 33-34 ºC and 50 ºC, while the surrounding water was at 27 ºC.
By 1500 ten earthquakes were recorded per hour. During 1600-1700 three eruption sites were visible; at one a pyroclastic cone was slightly above the sea surface. JMA reported that by the next day volcanic and seismic activity returned to usual levels, with zero to four earthquakes occurring per hour and no tremor events.
Sources: Volcano Research Center-Earthquake Research Institute (University of Tokyo), Japan Meteorological Agency (JMA), Reuters
From: Global Volcanism Program, 2001. Report on Ioto. In: Mayberry, G (ed.), Weekly Volcanic Activity Report 19 September-25 September 2001. Smithsonian Institution and US Geological Survey.
- Informations sur: Iwo-jima volcan