Earth:Monowai Seamount
Monowai is a volcanic seamount to the north of New Zealand. It is one of the most active volcanoes in the Kermadec volcanic arc and has erupted many times since 1977.[2][3] [ ⚑ ] 25°53′13″S 177°11′17″W / 25.887°S 177.188°W
Description
The summit of Monowai is approximately 132 metres (433 ft)[1] below sea level, considerably above the level of the nearby Tonga and Kermadec Trenches. The summit's position and depth changed between 1998 and 2004, due to a landslide and eruptive regrowth. A 1,500 metres (4,900 ft) deep caldera, 13 by 8 km (8.1 by 5.0 mi), lies 5 to 15 km (3.1–9.3 mi) NNE of the seamount's main cone.
Monowai was discovered by an aerial survey in 1944. Subsequent surveys showed evidence of significant change - sea discolouration and seismic activity. Studies between 1978 and 2007 showed the summit repeatedly rising and falling.[4]
2010s
Sonar data from the research ship R/V Sonne showed that between May 14 and June 1–2, 2011 the summit collapsed by as much as 18.8 m (62 ft) and lava flows had raised another area by 79.1 m (260 ft). Additionally a new volcanic cone was created. The R/V Sonne also observed the sea to be a yellowy-green with gas bubbles. Researchers believe that only Vesuvius and Mount St Helens have recorded larger growth rates.[4]
In August 2012, a 25,000 km2 (9,700 sq mi) floating raft of pumice was found offshore from New Zealand. It was initially believed to be from Monowai,[5][6] but Monowai was later ruled out as a possible source.[7]
See also
- List of volcanoes in New Zealand
References
- ↑ 1.0 1.1 "Monowai". Smithsonian Institution. https://volcano.si.edu/volcano.cfm?vn=242050.
- ↑ Global Volcanism Program: Monowai Seamount, eruptive history
- ↑ David Shukman (13 May 2012). "Rise and fall of underwater volcano revealed". BBC News. https://www.bbc.co.uk/news/science-environment-18040658. Retrieved 2012-05-13.
- ↑ 4.0 4.1 BBC, News, Science - Environment, Rise and fall of underwater volcano revealed. by David Shukman
- ↑ "25,000 sq km sea of pumice floats off New Zealand". Stuff.co.nz. 8 August 2012. http://www.stuff.co.nz/science/7455060/25-000-sq-km-sea-of-pumice-floats-off-New-Zealand. Retrieved 2012-08-10.
- ↑ "Vast volcanic 'raft' found in Pacific, near New Zealand". BBC News. 10 August 2012. https://www.bbc.co.uk/news/science-environment-19207810. Retrieved 2012-08-10.
- ↑ Cooke, Michelle (11 August 2012). "Scientists rock theory on pumice raft". Stuff.co.nz. http://www.stuff.co.nz/science/7461485/Scientists-rock-theory-on-pumice-raft. Retrieved 13 August 2012.
External links
- NOAA Ocean Explorer: Monowai
- Global Volcanism Program: Monowai Seamount
- Volcanic Activity Reports for Monowai Seamount, 2007
- Collapse and Re-growth of Monowai Submarine Volcano, Kermadec Arc, 1998-2004, Chadwick et al., 2005.
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