Immediate Report of Victoria University Of Wellington Antarctic Expedition 1987-88: VUWAE 32
MOUNT EREBUS SEISMIC STUDY (K044) - R.R. Dibble
MOUNT EREBUS SEISMIC STUDY (K044) - R.R. Dibble
To study the mechanism of the strombolian eruptions from the lava lake, as it reforms after disappearing in the 1984 activity, by a combination of TV surveillance, seismic infrasonic, and infrared monitoring of the eruptions. The study is made jointly by Victoria University of Wellington and the National Institute of Polar Research, Tokyo, and in close cooperation with New Mexico Institute of Mining and Technology. They are studying the release of volcanic gases from the lava lake, both during and between eruptions, by means of a correlation spectrometer, and by collecting samples of aerosols, sublimated salts, and newly ejected lava bombs.
The MEEMS project makes use of the old IMESS seismic array by unofficial courtesy of NSF. The infrasonic sensors, and the long period horizontal seismometer connected to the array at E1 and CON belong to VUW and NIPR respectively. The recording equipment at Scott Base belongs to NIPR, and the telemetry receiving equipment belongs to NSF, except for one bank of discriminators, which belongs to VUW. All the TV monitoring equipment belongs to VUW. Seismic recording materials are provided by NIPR, and videotapes are provided by VUW.
The year's work from the date K044 arrives, comprises servicing the Scott Base installation, and then the Erebus installations while observing the changes in crater temperature, activity and morphology. Ideally, all seismic tapes recorded since Winfly should be played back on to paper charts at Scott Base for distribution to NIPR, VUW, NMIMT, and GIUA. This enables analysis to begin promptly on data collected under our control. Priority is given to eruptions for which both TV and seismic data are available. If this is not done before the seismic tapes and playback machine are returned to Japan, the analysis will be delayed for about 8 months, and equipment faults may persist.
The planning phase was complicated by the initial belief by the Program Manager that the problems of international cooperation would force cancellation of the program. Accordingly, I accepted a 3 month fellowship in Japan from December 1987 through February 1988. Further, I was committed to attend the IUGG General Assembly in Vancouver, which clashed with the Tekapo Training Week. To the credit of all concerned, the Antarctic field programme did not suffer, and if anything, the personal relationships and understanding of the problems were improved all round. However, I remain convinced that regular attendance at Tekapo, and the event briefing session is essential in normal circumstances.
My cargo going South was no problem. It consisted of one large cargon (500 kg) of NZ and Japanese equipment and 150 lb hand carry (see Appendix 1 for detail). Susan Ellis had a problem coming north, because she had to bring all the recordings as hand carry luggage. She was relieved to be met at Christchurch, and given some help.
Cargo between NZ and Japan proved a problem, because there were no Japanese participants to smooth the way through Customs. Prof Kaminuma had difficulty clearing the seismic tape recordings when they arrived in Japan, even though he purchased and shipped them from Japan. His solution is to always use "Kaminuma and Dibble" as both consignor and consignee, to ensure that one of us is present at each end, but he was confused when tapes (used) I sent him arrived soon after he had sent new ones south, and thought his had done a round trip!
Preparations for the Field
|i)||The briefings by the OIC and DOIC were outstanding. Already a good liaison with NSF Rep existed, and no contact was necessary by me.|
|ii)||All the equipment requested from Ant Div was available and in good condition, except that the Generator (tested by Steve at S.B.) would not run.|
|iii)||Survival training was combined with "shakedown", and enabled the 'first timers' Terry and Susan to cope well with conditions on Erebus.|
|iv)||There were no significant delays.|
i) NZARP vehicles
Grizzly No.5 was in good order, and already tuned for high altitude when we received it. We had hoped to learn riding skills on the easy slopes at Fang, and be able to drive up Erebus, and so avoid helicopter delays, but the decision was to fly the Grizzly direct to the hut. The helo pilot declined, and delivered it to Fang when he came to lift us to the hut. So at short notice, we tried to drive it up. It wouldn't start (frozen switch), and we had to go up by helo as planned, and then Steve and Brian walked down to try again, and easily rode it up. The Grizzly proved equal to the NSF Bombadier, except it was harder to turn.
|12/11/87||Fang to hut. Hut to Truncated Cones and return.|
|13/11/87||Hut to Tramways rtn. Hut to Summit rtn.|
|15/11/87||Hut to Upper Hut rtn.page 33|
|16/11/87||Hut to Cones rtn. Hut to Summit rtn.|
|17/11/87||Hut to Summit rtn|
|18/11/87||Hutt to Summit rtn.|
|19/11/87||Hut to Fang, for rtn to Scott Base by helo|
About half a tank of fuel was used per day. The windscreen broke in half when I was trying to secure it while the helo was waiting to take us up to the hut on 12/11/87.
ii) Helicopter Operations
Our put in was combined with K191, and took 3 lifts to Fang on 9/11/87.
I Our lift to the Hut was delayed 1 day by weather. On 12/11/87, 2 cargo trips from S.B. to hut, and then 1 to Fang with the Grizzly, and 2 from Fang to Hut were made. The last of these medivae'ed Garth to Scott Base with a viral infection.
K191 returned to S.B. in 1 flight on 16/11/87. K044 returned in 2 nights, 1 from Fang with the Grizzly, and 1 from the hut.
The initial lift on 9/11/87 was free, and the return from Fang was a backload on S081's put in.
|4 Nov||Dibble, Ball and Ellis fly to S.B. by Starlifter. Begin servicing MEEMS equipment at S.B.|
|5 Nov||Continue servicing. Begin survival course.|
|6 Nov||Finish survival course. Prepare field equipment.|
|7 Nov||Prepare field equipment. Service MEEMS.|
|8 Nov||As for yesterday.|
|9 Nov||Put in to Fang with K191. 3 helo flights.|
|10 Nov||Acclimatising. Weather deteriorating.|
|11 Nov||Acclimatising. Weather improving.|
|12 Nov||Helo lift to Hut. Service Cones telemetry station.|
|13 Nov||K191 plus Steve and Susan survey Tramways, and Dibble and Ball retrieve TV camera from Summit.|
|14 Nov||Modify and test TV camera. Rebuild VLF microphone.|
|15 Nov||Service E1 telemetry station.|
|16 Nov||Install VLF mic at Cones. Reinstall TV camera, and shift transmitter and antenna at Summit. Incomplete.|
|17 Nov||Continue infrared survey and TV servicing.|
|18 Nov||Complete infrared survey and TV service. Service E1 telemetry again. Rebuild VLF mic for E1.page 34|
|19 Nov||Return to S.B., 2 flights.|
|20-23 Nov||Record data and revise instructions for MEEMS.|
|24 Nov||Dibble returns to NZ.|
|25 Nov-5 Dec||Increase the seismic recordings to 8 channels.|
|6 Dec||Ball returns to NZ.|
|7 Dec-7 Jan||Recording and processing MEEMS data.|
|7 Jan||Ellis returns to NZ.|
Mr Steve Lassky will include our weather in his report.
No significant accidents occurred, but people using toboggans on difficult terrain should get practise before their put in.
The Dome tents again proved excellent on the Erebus Plateau.
Chocolate biscuits and instant noodles should be a standard item in ration boxes.
Our troubles starting the generator and Grizzly made us wish for better instructions in the Field Manual, particularly about the complexity of the Grizzly starter switch. Perhaps more comprehensive field manuals should be supplied with these equipment items.
The Tait VHF handheld radios were again outstanding for communicating with "Scott Base" and with the Science Lab itself, via the repeater station. Battery charging by the solar panels was excellent. The small PEL sets on 5400 kHz were again useless at Fang Glacier, which is within the skip distance, and in the shadow of Erebus.
The general efficiency of Scott Base radio skeds was excellent, which helped the smooth running of the field program this year.
We made considerable use of the Scott Base Science lab, and were very grateful to Paul Purvis of Telecom, who helped out after the technician assigned to MEEMS page 35 resigned, until his replacement arrived. It is pleasing that the ionosonde is no longer next to our telemetry receivers, and that interference is reduced.
- Dual tracking power supply
- Tunable narrow band voltmeter for multiplexed subcarriers
- Portable battery powered oscilloscope for outside use.
Better designation of storage areas for spares, and recording materials and box files for service manuals and instructions would help the lab technicians.
The two NSF huts on Erebus were in good condition, and contain adequate food, cooking equipment (white spirit) and furniture. Both have some bedding inside, and a survival box outside. Also fire extinguishers and oxygen bottles, but those in the upper hut are of uncertain condition. Both sites are tidy.
All garbage and sewerage was retroed to McMurdo by helo.