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Report on Late (Tonga) — December 1979


Late

Scientific Event Alert Network Bulletin, vol. 4, no. 12 (December 1979)
Managing Editor: David Squires.

Late (Tonga) Report of ash near the summit proves false

Please cite this report as:

Global Volcanism Program, 1979. Report on Late (Tonga) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 4:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197912-243090



Late

Tonga

18.806°S, 174.65°W; summit elev. 540 m

All times are local (unless otherwise noted)


Most of the reported eruption sites were investigated during the 11-18 July cruise of the Fijian research vessel RV Bulikula. An inspection of Late Island, where whitish material thought to be ash reportedly covered the summit cone on 18 and 21 May, revealed no trace of a whitish covering other than scattered patches of white lichen, and no evidence of a recent eruption.

Geological Summary. The small, 6-km-wide circular island of Late, lying along the Tofua volcanic arc about 55 km WSW of the island of Vavau, contains a 400-m-wide, 150-m-deep summit crater with an ephemeral lake. The largely submerged basaltic-andesite to andesitic volcano rises 1500 m from the sea floor, with its conical summit reaching 540 m above sea level. Cinder cones are found north of the summit crater, west and north of a semicircular plateau 100-150 m below the summit, and on the NW coast. A graben-like structure on the NE flank contains two large pit craters, the lower of which is partially filled by a saltwater lake. Only two eruptions have occurred in historical time, both from NE-flank craters, which produced explosive activity and possible lava flows in 1790 and 1854.

Information Contacts: D. Woodhall and R. Richmond, Mineral Resources Dept., Fiji; D. Tuni, Ministry of Natural Resources, Solomon Islands.