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Antarctic Ice Caves

Ice Caves on Ross Island Antarctica

Ross Island is directly south of New Zealand, across the Southern Ocean down a line of longitude of approximately 4086 kilometres.

The ice caves on Ross Island are found in the Glaciers and Ice Falls in the locality of Castle Rock, and flow either onto the permanent Ross Ice Shelf on one side, or the seasonal Sea Ice of McMurdo Sound on the other.

Erebus Ice Tongue

This glacier pushes out over sea ice into McMurdo Sound. It can be up to 11 kilometres long. About half of its bulk floats on salt water. It is locked into position by 2 metre thick Sea Ice. The differing densities of both salt water and its ice, and frozen fresh water (snow) which then turns into blue glacial ice, keep it afloat. (Blue ice is less dense)

It has been known to break up occasionally, either partially or completely, usually during bad storms and periods of severe ice breakout from McMurdo Sound.  Capt. Scott records one such event and the total devastation it caused.

I visited the caves in the Erebus Ice Tongue during Christmas of 1993 and October 1994. The first visit was high summer in the Antarctic, with mild temperatures rising to about -5 degrees C. The latter visit was at the end of the Antarctic winter under much more severe conditions. Around -40 degrees C. It was cooler in the caves but of course no wind chill, so it was a very peaceful place to be, cut off literally from the known world.

The colour spectrum of the light in the caves is a most intense blue. Fading to the darkest blacks in the deepest sections.

During the October 1994 visit the entrances and any vertical cracks were shot through with golds and yellows, purples and magentas. A very special place and this visit whilst extremely hazardous, was to be one of the last of its kind. We were 7 people, 5 New Zealand based, One US scientist and his American Indian partner. Future trips were deemed to be too dangerous. So these trips were the end of an era.

The Erebus Glacial Tongue Visit October 1994

This was the penultimate visit of all our explorations.

In spring it was much colder around -40 to -45 degrees C but there was daylight for 12 hours a day. We had to be very careful both outside and inside the caves, but as a bonus, there was as is usual no wind inside the caves, so they became havens from the extreme outside environment, even though they were at -45 degrees C.

Every step had to be planned and every single move thought out. This kind of thinking and working out the moves ahead had become normal behaviour after 12 months on the Ice and a Winter Over. It really becomes habitual and some say it becomes a phobic state of being. Almost sloth like.

But one thing is for sure, the ice is out to get you sooner or later depending on your risk appetite. A twisted ankle or broken bone would have meant a full S.A.R callout putting many others at risk. And the embarrassment, part of my role on the Ice was the S.A.R. co-ordinator for the US and Kiwi teams.

My primary role was the Engineering Services Manager, Scott Base and all Antarctic sites controlled by New Zealand, which meant I also had to ensure our Swedish Haggland ATV vehicles were fit for purpose, engines and essential equipment kept warm at all times, going or not. Ready to go.

If we were camped a portable power plant was run up and electrically connected to heating elements in the engine, radiator, and under battery heating packs. Spares on board and all radio comms working. i.e. hand held radio batteries not frozen. I recall staggering out of the sleeping bag about 0400 hours one very cold, beautifully star light morning to refuel the generator. Spilling petrol on my woollen gloved hands which immediately froze as it evaporated. Thinking "My God this is it, I’m in for frost bite. The continent finally got me". Luckily thanks to relatively warmer armpits, after an hour or so I had circulation back. A near miss narrowly averted.

Winter 1994

Visiting the Castle Rock Ice Fall caves during the complete 24hr a day darkness and in the middle of winter was a real test of extreme caving into this frozen world.

It has to be a full crampon trip with ice gear on top of multi-layer survival clothing in temperatures of around -40 to -45 degrees C,  but positively the ice is much more stable at this time of the year.  This makes for a sublime world of hard blue ice, snow crystals, all light is artificial in stark and complete contrast to "summer"

This trip will always stay in my memory which is just as well because during this trip under ”ground”  after just a few photographs the camera froze ! We hit the coldest temperature ever on this trip of -50 degrees C.  A completely and totally humbling experience living in an awesome frozen world. All molecular activity closing down.

Indeed it was a tough place to be, affording no compromises in approach. And with the possibility of a hidden crevasse, balanced by the extreme cold, and that all crevasse "bridges" would be frozen very solidly. All risks were minimised by roping up the team with 250 mm ice anchors in the side walls. Floor anchors were also driven in and sealed with "Antarctic Concrete".  A litre of urine or so.  A job for the boys. Our one female on this trip was a Nurse so any frost bite would have been attended to promptly. Thankfully for her this wasn’t the case.

We used white spirits lighting and cookers and camped inside the caves overnight. The cool eerie glow of this very old fashioned form of lighting was spectacular. The air in the caves was only about 15% Relative Humidity so very dry. Static was a problem. Rubbing clothing produced blue sparks like a firework.

Sleeping in a double feather down sleeping bag whilst also wearing a harness and roped to the wall was interesting.

Possibly you need to be adventurous or foolish or very curious to attempt these trips. But they reward those fortunate enough to have taken part for life.

Castle Rock Ice Fall

Castle Rock Ice Fall is about 5 kms from Scott Base, across the temporary sea ice of the Ross Sea and it is a prominent landmark which has an unfortunate history.

Many memorial crosses are erected in this area, where pioneers from the Heroic Age came to lose their lives. Weather patterns were unknown, equipment basic, and knowledge and experience lacking, and they died often by falling off the cliffs in storms. Lessons were learnt, they gave those guys the tests first and the training came later. The early British pioneers where indeed a tough lot at all levels.

These caves are formed under the Ice Fall by sublimation of their weakest sections.  And these caves last for many years following structural aberrations in the Ice Structure. And they can be at any angle.

This is a beautiful place internally with some deep drops into crevasses. Such an extreme and multi hazardous environment needs to be treated with the utmost respect.

It was a privilege to visit the area. That the rewards were immense goes without saying and a very good level of fitness both mental and physical is essential in order to assess the risks. Only careful meticulous planning can achieve all this. And at best it is impossible to eliminate all the risks, most are only minimised.

Interestingly a group culture developed symbiotically, often no words were spoken, and the values which included no drinking alcohol for 24 hours before hand, carrying no injuries, and no negative thinking patterns, good ice knowledge and technique, self-reliance etc. You just would not be invited to join the group otherwise. So the well-equipped, well experienced, and happy well balanced got to go.

And we were roped up at all times from the moment we stepped inside the caves. With ice anchors into the walls and floor. Only occasionally were the floors level, and they were mostly blue ice.

You just never know what will happen when you take crampons off!  Blue Ice is unforgiving, as hard as steel and very slick. It can cause severe injuries in seconds, plus unstoppable slides. Nature doesn’t provide flat surfaces it seems. And just like on the surface you might find a hidden crevasse. (Don’t even want to think about it).

During these visits it is a survival technique to buddy up. That is you have a care of duty to observe a mate (buddy). You keep an eye on them for any unusual developing traits either mental or physical. For instance they may have had a fall and be slightly concussed but be to embarrassed to have mentioned it, or little white areas in the face around the nose or exposed ears can signal frost nip leading to full blown bite. Slurred speech or slower than normal movements can indicate the onset of hyperthermia or a head injury.

Proud O.A.E.s  (Old Antarctic Explorers) tend not to report their personal issues easily so it is an essential technique. And the big guys usually go down first. That is an established fact, and it is an integrated and complicated set of circumstances which cause it, and is predominately calorie and fitness based. But so much goes back to what Capt. Scott referred to as the Headpiece.

Castle Rock in the winter is a place of extreme danger for the "newby", the inexperienced or badly organized group. But for the lucky, (good planning coupled with good experience and taking opportunity) the final result is a life time of very satisfying memory.

David Lucas.
11th Jan 2016

David Lucas. Summary of role at Scott Base, Antarctica August 1993 to November 1994. Winter-over 1994.


N.Z. Antarctic Program Deputy Winter Base Manager & Engineering Services Manager,  Scott Base,  Antarctica 
Co-Base Manager with the Senior New Zealand Representative in Antarctica (Senzrep). Managed Scott Base to the satisfaction of the Director of the New Zealand Antarctic Program. Directly responsible for all Scott Base staff and their health and safety, winter work programs, weekly management meetings with United States McMurdo Base Winter Managers. All planning and implementation for Scott Base winter over activities.  Plus all engineering duties below.


Key Achievements

No accidents or injuries throughout the Winter Period.
Met the established conditions for co-operation, communications, (inter-base and inter-nationally) and mutual support with Antarctica NZ, the United States Antarctic Programme Managers and the US National Science Foundation.
Successfully part managed the Midwinter air drop with the US personal.


Engineering Services Manager N.Z. Antarctic Programme  Scott Base,  Antarctica

Responsible for the management of all Engineering and Building facilities at Scott Base and all other Antarctic Sites including Electrical Supply and Equipment, Heating and Ventilation, Mechanical Services, Water Supply, Buildings, Roads and Grounds maintenance, Waste Disposal, Refrigeration, Supply and Storage of Fuels, Control of the day-to-day activities of up to 10 tradespersons. Directly responsible for the operation and maintenance of 3 Power Generators and a Reverse Osmosis Water Making Plant. Senior Member of the Summer Management Team responsible to the Senior Representative of New Zealand.


Key Achievements

Achieved a 0% disrupted electrical power supply for 13 months.
No water restrictions for 13 month.
All of the Scott Base buildings where fully maintained to Antarctic Standards.
All roads kept open for 13 months.
No failures of any kind with engineering equipment.
All staff relationships ran well to the satisfaction of all concerned.


Additionally Officer on the Ice for the Antarctic Heritage Society responsible for the preservation and upkeep of the Historic Huts on Ross island at Cape Evans, Cape Royds and Hut Point.


Joint USARP S.A.R. co-ordinator.

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