VUWAE 18A

At 1.30 a.m. on September 5, Kyle and others of the N.Z. Dry Valley Drilling Project (DVDP) drill crew took off in a U.S. Navy C130 Hercules from Christchurch. This, the third of four winter flights (Winfly) landed at McMurdo Station at 9.25 a.m. in clear calm weather to a rising sun and a temperature of - 25°C.

During the next 9 or so weeks Kyle was site geologist at DVDP 3. After ice was drilled from the casing of DVDP 2 the Longyear wireline drill rig was moved 3 m to the north and on September 20 DVDP 3 was commenced. Drilling continued until October 19 when the rig was dismantled for transportation to Marble Point. All the core was examined and logged in the Earth Science Lab. At McMurdo Station.

Following several false starts, P. Kyle, Ross Cooper (D.S.I.R. field assistant) and Sam Treves (DVDP project scientist) flew by helo to Mt. Erebus on November 11. After establishing camp the party climbed the 120 m to the crater to inspect the crater. The weather was clear and calm with a view of the inner crater only partly obscured by steam and vapour. This was the best view in two years of visits that Kyle had ever had into the crater. A dramatic sight greeted the observers. On the north-eastern side of the inner crater lava was flowing westward from a vent into a partially frozen lava lake. The surface of the 8 - 10 m wide flow was partly congealed green-grey flow banded ropey lava. As the highly viscous lava slowly flowed the surface would break revealing the deep red molten lava lying beneath the thin solidified skin.

The inner crater is divided into half by a small ridge running east-west. Lava was first observed on the northern side of the ridge during the 1972-73 season by a NZARP party which included Kyle. During the present visit the lava was still confined to the northern side of the dividing ridge; however it was apparent that a considerable amount of lava had flowed into the area. Much of what was irregular crater floor dotted with fumaroles in 1972-73 was now flat frozen lava. The southern side of the inner crater was snow-covered with a few groups of small, nosiy fumaroles.

After inspecting the crater the party returned to the camp. In the early evening Treves returned to McMurdo by helo. Cooper and Kyle had both developed thumping headaches by evening as a result of the altitude change. Following a good, but very cold, night's sleep the headaches had subsided. In deteriorating weather an inspection of fumarolic ice towers was made next morning to find a site to install a slow recording seismograph. In the afternoon 70 kg of equipment was carried to the site in a warm (+ 1°C) underground ice cave, 400 m downhill from the camp. The seismometer did not operate, however, and had to be returned to camp for repairs. We were exhausted by the heavy work but apart from that did not seem to suffer any altitude effects.

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Severe blizzard conditions for the next four days restricted any movement from the tent. Attempts to repair the seismometer were unsuccessful and so the main scientific objective of the visit was over.

Over the next week poor weather allowed only trips a short distance from the camp. The crater rim was visited almost daily; however dense cloud and vapour obscured any view of the inner crater and the lava. Depth measurements of the main crater floor were made using an inclinometer and a 50 m measuring tape. A depth of about 130 m was estimated. Heavy snow cover around the crater rim limited any geological work. On the evening of November 24, Dr. Haroun Tazieff and Sam Treves arrived by helo. In very cold, windy conditions the party visited the crater; cloud again completely obscured any view into the crater. The following day the party returned to Scott Base by helo.