Available Weekly Reports
13 July-19 July 2011
Based on information from Tonga Meteorological Services and pilot observations, the Wellington VAAC reported that a cloud from Tofua rose to an altitude of 1.2 km (4,000 ft) a.s.l.
Sources: Wellington Volcanic Ash Advisory Center (VAAC)
13 July 2011Back to Top
Summary of eruption dates and Volcanic Explosivity Indices (VEI).
|Start Date||Stop Date||Eruption Certainty||VEI||Evidence||Activity Area or Unit|
|2009 Mar||2009 Mar||Confirmed||1||Historical||Lofia crater|
|[ 2008 Mar 7 ]||[ 2008 Nov 21 ]||Uncertain||1||Lofia crater|
|2006 May||2006 Jun||Confirmed||0||Historical||Lofia crater|
|2004 Oct||Unknown||Confirmed||1||Historical||Lofia crater|
|[ 2004 Mar 19 ]||[ 2004 May 29 ]||Uncertain||1|
|[ 1993 Apr 29 ]||[ Unknown ]||Uncertain||0||Northern part of caldera|
|1958 Dec 31 ± 120 days||1960 (?)||Confirmed||2||Historical||Northern part of caldera|
|1906 Dec||Unknown||Confirmed||2||Historical||Northern part of caldera|
|1906 Jan||1906 Feb||Confirmed||2||Historical||Northern part of caldera|
|1885 Oct (in or before)||Unknown||Confirmed||2||Historical|
The low, forested Tofua Island in the central part of the Tonga Islands group is the emergent summit of a large stratovolcano that was seen in eruption by Captain Cook in 1774. The first Caucasian to set foot on the 515-m-high island was Capt. William Bligh in 1789, just after the renowned mutiny on the "Bounty." The volcano's summit contains a 5-km-wide caldera whose walls drop steeply about 500 m. Three post-caldera cones were constructed at the northern end of a cold fresh-water caldera lake, whose surface lies only 30 m above sea level. The easternmost cone has three craters and produced young basaltic-andesite lava flows, some of which traveled into the caldera lake. The largest and northernmost of the cones, Lofia, has a steep-sided crater that is 70 m wide and 120 m deep and has been the source of historical eruptions, first reported in the 18th century. The fumarolically active crater of Lofia has a flat floor formed by a ponded lava flow.