Active submarine volcano sampled



On June 4, 1982, two full dredge hauls of fresh olivine basalt were recovered from the upper flanks of Kavachi submarine volcano, Solomon Islands, from water depths of 400 and 900 m. The shallower dredge site was within one-half mile of the active submarine vent evidenced at the surface by an area of slick water, probably caused by gas emissions. Kavachi is a composite stratovolcano located on the ‘trench-slope break’ or ‘outer-arc high’ of the New Georgia Group, approximately 35 km seaward of the main volcanic line and only 30 km landward of the base of the trench inner wall. The volcano has been observed to erupt every year or two for at least the last 30 years (see cover photographs). An island formed in 1952, 1961, 1965, and 1978, but in each case it rapidly eroded below sea level. The latest eruption was observed by Solair pilots during the several weeks up to and including May 18, 1982.