Today, we did the Ice Cave... the biggest in the world! The remarkable thing is that mere mortals... such as Joye and myself... were able to get to the cave... and get out again alive.. all within a period of 3 hours. The opening to the cave sits high on a sheer cliff face high in the mountains above Werfen in Austria. To get there, we zigzagged our way up the mountain and parked the car below the chairlift at an elevation of 1,000 metres... the chairlift elevated us up another 500 metres to a ledge 100 metres below the cave mouth. We hiked up that altitude... with a pedestrian tunnel at one point and a short bridge spanning a 200 ravine at another point. Spectacular views up and down the valley were marred by thick haze... (no wonder the EU is so keen on CO2 abatement agreements.)
At the mouth of the cave, we looked back on the terrain we had covered. The day was hot... another 35° day... but we had barely raised a sweat. The early tourists used to take 2 days or more... a walk we completed in 20 minutes... thanks to some great engineering in building the chairlift and paths. At the cave mouth, we donned our overall, jacket, beanie and gloves. The temperature inside the cave is invariably 0°... so you need to be well rugged. (We lent a pullover to the guy queuing behind us... he came with just a cotton shirt.)
Before describing what we found inside the cave, you may be interested in how the ice forms there... and not in other caves... I think it's fascinating. The cave system is extensive... 43 klms in length through calcitrean rock... formed as an underground stream when the land level was in a valley... before the European Alps pushed its head up to the clouds. The cave system has one entrance high up on the cliff face (where we entered) and gently runs down to have another entrance at valley level. In winter, the air on the mountain is - 30° Celsius. The wind blows the freezing air into the cave's mouth. The heavy cold air causes a current that pushes any warm air down the cave system. The movement of freezing air causes the rock surfaces in the cave to get extremely cold. In mid-winter, all surface moisture is frozen... and there is no deposit of ice in the cave. But, come spring, surface ice starts to melt and seep through the calcitrean stone's cracks and crevasses. Water drips into the caves... but finds a freezer... and turns back into ice within the caves. Come summer, the temperature inside the cave is not so freezing... dripping water does not freeze... indeed, it melts some of the existing ice to supplement the underground stream. Are you with me so far. Freeze in winter... deposit new ice in spring... melt some of the existing ice in summer. It's a bit like growth rings on a tree... each year, the ice is a tiny bit different and can be seen as a distinct layer. Where melting exceeds deposits in the year, no layer is left... the scientists need to be careful in reading the growth rings. Some of the 'lakes' in the cave are over 8 metres deep... and the growth rings capture atmospheric conditions for a period of over 5,000 years.
When we were ready to enter the cave, they opened a door that released a wind of gale force strength. We had to push forward very hard to get through the opening door. Every second couple in our group was given a lantern burning a chemical that produces a light... but very little heat. Our guide would burn magnesium strips when he wanted light to fill the big cathedrals in the system... again on the basis of minimising heat and maximising light. Inside the cave, we followed a walkway rising 700 steps (130 metres)... and another 700 steps on the way back. We covered the first kilometre into the cave... the ice cave feature doesn't go beyond the first kilometre. There were stalactites and stalagmites made from crystal clear spring water... and we had the organ pipes... veils... and unusual shapes that we were supposed to recognise as elephants (or whatever).
This cave wasn't as scary as the Hobbit Cave in Slovenia... or as big as the caves in Croatia... but this one was special... walking in a tube of ice for 100 metres was something we had not done before. For us, seeing nature producing another type of wonder gave us an emotional lift for the day.
No comments:
Post a Comment