95, 105 p. (includes map in back pocket). Res., 156: 252-265. More than 200 earthquakes were recorded in the first 24 hours, with many of the larger events felt on the island. There were, however, no significant changes in the appearance and emission rate of thermal fluids from the main area of geothermal discharge along the W shore of Green Lake since the last visit of RV Vulkanolog in March 1988.

Observations from a simple oceanic arc volcano: Raoul Island, Kermadec Arc, SW Pacific. In Denham Bay GNS scientists observed a weak plume of discolored water approximately coincident with the vent area. Vigorous upwelling and gas discharge was still obvious through Green Lake, which appeared very warm. When one is found the date, time, location, and intensity are recorded. Lloyd E F, Nathan S, 1981. Primary records indicate that there were eruptions in both the Denham Bay and Raoul calderas between June and October 1870. Table 1. 4 (CD 303), New Zealand Ministry of Civil Defence, 45 p. (Booklet) ISBN 0-477-07472-3Lloyd, E.F., and Nathan, S., 1981, Geology and tephrochronology of Raoul Island, Kermadec Group, New Zealand: New Zealand Geological Survey Bulletin, no. Lloyd, E.F. and Nathan, S., 1981, Geology and tephrochronology of Raoul Island, Kermadec Group, New Zealand: New Zealand Geological Survey Bulletin, no. GNS volcanologist Bruce Christenson stated, "From our aerial observations, it is clear that the heat, gas, and water that are discharging into Green Lake are making this part of the volcano's hydrothermal system unstable." There was no evidence of further eruptions after 17 March.

Heavy seas prevented landing on Curtis Island, the other island in the Kermadecs showing thermal activity.". Still and video footage taken of the post-eruptive scene on 17 March 2006 showed many new craters and reactivation of 1964 craters. A 5-hectare (12-acre) area around Green Lake was affected with ash, mud and boulders. There were also discharges in the rocky bay halfway between Hutchison Bluff and the NW end of Denham beach (figure 2A). Information Contacts: Brad Scott, Institute of Geological and Nuclear Sciences (GNS), Wairakei Research Centre, 114 Karetoto Road, Taupo, New Zealand (URL: http://www.geonet.org.nz/, http://www.gns.cri.nz/). Because the swarm may have been precursory to an eruption, the meteorological station staff of 4 men and 1 dog was evacuated by ship to a location 10 km from the island. The main steam columns were derived from Crater I, Marker Bay, and Crater XI. Richard J J, 1962. Raoul Island remained at Alert Level 2 (minor eruptive activity). The island’s irregular anvil shape is due to a combination of volcanic activity and marine erosion. The older caldera cuts the center of Raoul Island and is about 2.5 x 3.5 km wide. The geology of Raoul Island, Kermadec Group, southwest Pacific. Landsliding and collapse also blocked Crater I. SO2 data was collected by the Aura Ozone Monitoring Instrument (OMI), which is affiliated with the University of Maryland, the US National Aeronautics and Space Administration (NASA), the Royal Netherlands Meteorological Institute (KNMI), and the Finnish Meteorological Institute (FMI).

Then on 17 March at 8.21 a.m. there was a sudden explosive eruption near Green Lake. All historic eruptions include explosive activity within the Raoul caldera close to Green Lake, probably caused by disruption of the geothermal system as magma moves upwards. Volc Seism, 16: 171-180 (English translation). Seismicity continued to decline at Raoul Island through 7 April. A news story reported that the missing man left around 0730 on 17 March to walk to Green Lake. A plume of discoloured bubbling water containing pumice fragments was observed in Denham Bay in November and December. There was evidence of hydrothermal seepage along most of the beach (milky discoloration indicating mixing of hydrothermal brine and seawater). New Zeal Ministry Civil Defense, Volc Hazards Inf Ser, 4: 1-45. Gas compositions point to an essentially hydrothermal origin with insignificant contributions from high-temperature magmatic gases. Geotherm. Res., 190: 219-234. Over the last few days the level of earthquake activity at or close to Raoul Island continued to decline and in early April there were only 2-5 earthquakes per day being recorded. New Zeal Geol Surv Bull, 95: 1-102. An hour later the volcano erupted. The water temperature, obtained from a thermal infrared satellite image taken on 11 April 2006, was 39.2°C, was 7°C above the average water temperature in April, but had returned to seasonal temperatures by August 2006. Smith I E M, Worthington T J, Price R C, Stewart R B, Maas R, 2006. Which volcano to choose? ; Lloyd, E.F.; Smith, I.E.M. Steve Sherburn of GNS reported on 24 March on the GeoNet website (the New Zealand GeoNet Project provides real-time monitoring and data collection for rapid response and research into earthquake, volcano, landslide, and tsunami hazards) that over the last few days the level of earthquake activity at or close to Raoul Island had continued to decline to a current level of only 5-10 earthquakes per day, most of which were probably too small to be felt on the island. Fortunately the request was declined by the New Zealand government – for political reasons. The following observations, made by scientists from the USSR and New Zealand during a cruise of the RV Vulkanolog, were reported by W.F. J. Volcanol. ; and Nathan, S., 1992, Volcanic hazards in the Kermadec Islands, and at submarine volcanoes between Southern Tonga and New Zealand: Volcanic Hazards Information Series, no. © Crown Copyright.

The area devastated in the centre of the Raoul caldera was soon covered in trees that grow rapidly in the subtropical environment. Volcanic hazards in the Kermadec Islands, and at submarine volcanoes between southern Tonga and New Zealand. There is no Emissions History data available for Raoul Island. There is no Deformation History data available for Raoul Island. There was also a new feature about 200-300 m N of Green Lake's Crater XII (figure 2B); the new feature included a moat near the edge of the crater floor, which contained a vigorously active vent. There is no unequivocal seismic evidence for magma movement (such as the strong volcanic tremor observed before the 1964 eruption). Raoul Island remained at Alert Level 2 (minor eruptive activity). Latter, J.H. The strongest earthquake swarm since the 1964 eruption began at 0150 on 9 March. Latter, IGNS Wellington. Only 1 to 5 earthquakes were recorded per day in the months following the eruption. Brad Scott reported on 3 April 2006 that activity continued to decline in the Green Lake crater area. Chemical composition (in mmol/mol of dry gas) of steam samples collected from the main fumarolic vents on Raoul Island in December 1964 (shortly after the 1964 eruption; Weissberg and Sarbutt, 1966) and during the March 1988 cruise of the RV Vulkanolog. Information Contacts: Steve Sherburn, GeoNet Science (GNS), Wairakei Research Centre, Private Bag 2000, Taupo, New Zealand; Ian Wright, Ocean Geology group, National Institute of Water & Atmospheric Research (NIWA), PO Box 14901, Wellington, New Zealand (URL: http://www.niwascience.co.nz); Roger Matthews, North Shore City Council, 1 The Strand, Takapuna Private Bag 93500, Takapuna, North Shore City, New Zealand (URL: http://www.northshorecity.govt.nz/).
An explosive eruption commencing about 6am on 22 November opened a large vent near Green Lake which devastated the immediate area, and there were eleven other small vents within the Raoul caldera. Raoul Island is the emergent part of a large submarine volcano, and its irregular, anvil-like shape is due to a combination of volcanic activity and erosion. According to Christenson, "one explanation for the increased hydrothermal activity is that it is being driven by the intrusion of magma at depth.". On the afternoon of 9 March an overflight revealed no indications of volcanic activity. ... Seismicity continued to decline at Raoul Island through 7 April. GeoNet Science (GNS) summarized the decreased activity in their Volcano Alert Bulletin of 18 September 2006.
An eruption took place on 17 March 2006 at Raoul Island, killing one person. It is the emergent part of a large volcano, almost 20 kilometres in diameter. The island’s irregular anvil shape is due to a combination of volcanic activity and marine erosion. The highest SO2 values stood over and adjacent to the island and reached as high as two Dobson Units (DU, figure 4). The last eruption from the Green Lake area occurred during November 1964-April 1965. A similar event occurred in approximately the same location some months previously but was not reported because activity was attributed to whales. Based on data from the seismograph on the island, the eruption appears to have continued for up to 30 minutes, although the most intense part of the eruption lasted for only 5 to 10 minutes.

Raoul Island remained at Alert Level 2 (minor eruptive activity). Raoul Island remained at Alert Level 2 (minor eruptive activity). Res., 90: 29-48. Many of these were drowned as a result of lake-level rise. A similar swarm of minor shocks (Adams and Dibble, 1967) and an increase in hydrothermal activity (Healy et al., 1965) preceded the 1964 eruption. Its long axis is parallel to the tectonic …

Detailed onshore and offshore investigations show that there are two large collapse calderas (Raoul and Denham), both of which have erupted frequently over the last few thousand years. Just west of Raoul Caldera is Denham Bay, a second caldera which has been flooded by the sea.

No thermal anomalies were detected by the MODIS satellite system during March 2006.