02 November 2004

Holy drill bit.

Today's story is all about drilling big holes in thick Ice.  Dragging the nice new dive huts over them is the gravy. The drilling process is the most interesting and therefore I will inundate you with extensive pictures of the event.

We have finished our work at Cinder Cones and now need to go find out what condition the experiment that has been left at Turtle Rock is in. 

At 8:15 we meet the driller Tom and his apprentice Trina. Linking up all the various sleds, huts and other components necessary to the day's activities goes smoothly. This is a testament to the skill we usually encounter whenever we interface with the folks in Fleet Ops. When we get everything rolling down the road our convoy consists of a Challenger bulldozer pulling the drill trailer pulling the 20 foot dive hut and lastly a small sled with the four foot diameter drill bit strapped to it. We are in the sports car - a Pisten Bully - we move a bit faster and soon we are out in front and set the cruise control for the one hour drive ahead of us. 

 

We get the convoy headed down the road

The sun is bright today and the winds are calm. The temp is about 10F so this for us is a great day. Turtle Rock as a little more then twice as far away as Cinder Cones but the road is straight and soft with fluffy snow cushioning our ride and we are making good time. Just past the turn that takes you to the Penguin Ranch is the selected spot for us to create our new driveway. We turn sharply off the flagged route and head across open plateau towards the shell-shaped rock dome in the shimmering distance. Sastrugi are everywhere and the hummocky surface slows our progress and makes it impossible to finish the morning nap. Winding our way through three foot mounds of snow brings the dome closer.

Turtle Rock gets its name because its rounded ridge looks like a tortoise surfacing in the ice. It's in a bay that is bisected with the Erebus Glacier tongue. This finger of ice is about 10 miles long and resembles from the air a herring bone. It's an amazing geographic land mark; of course it is at present surrounded by frozen sea ice. Turtle Rock is an island in this bay with the experiments in place on its slope 70 feet beneath the ice. 

As we near Turtle Rock proper we start to notice lots of old cracks in the blue ice. We must wind our way around these even though they are obviously last year's cracks and have solidified over the winter. This area has a dreadful history. Several vehicles have broken through the ice near here, one even taking a diver with it.

We are faster than the "Wagon Train" of hardware that pursues us. They arrive just as we finish our GPS survey of the precise locations of last years holes. The main hole site has quite a bit old snow over it, so Trina starts in on it with the massive blade of the Challenger.  We marvel at her mastery of snow carving as we bask in the sun and spend a few moments planning the next moves. Next on the list is the solar panel we brought for the hut. A few lag bolts secure it to the nearly flat roof of the hut, firmly attached against any future wind storms. A flat mounted solar panel might seem inefficient but with the sun endlessly circling the sky we have found it better than the alternative of pointing it North. The solar panel's only purpose is to charge the battery that runs the hole fan. This small fan suspends from the ceiling above the hole and blows the 20 degree warmer air from the top of the hut down a plastic tube spewing it into our dive hole. The heat transfer helps slow the process of the hole freezing.

Now it's time to drill. The sled with the rig gets positioned where the GPS has dutifully directed us. The boom swings into the erect mode then the big auger starts spinning and chipping its way down. Piles of white ice chips exude and its fluid motion makes it seem as if we had hit water already. After a minute goes by the auger laden with chips returns from the depth, pauses, then with a jerk spins at full speed flinging still more ice chips around the hole. This clearing process repeats itself several times revealing a 10 foot deep perfectly round hole in the ice. The walls of the hole are stratified with lines indicating layers of plankton and wind blown debris. Meanwhile we shovel a small exit channel in the mountain of chips forming around the lip of the hole. Soon there is a gurgle and a deluge of water comes surging  up the hole. The auger assists by rapidly extracting itself, most of the remaining ice chips, and several hundred gallons of emerald sea water. The slurry flows through the channel hopefully removing the loose ice flakes and chunks. The auger plunges several times, pumping more water and chips in an attempt to clear the hole of all the brash. It's really an amazing process to go from 15 foot thick ice to a nearly perfect dive hole in about 10 minutes. 

Next the massive blade of the bulldozer back blades the mountain of slush and chips away leaving us a perfect hole in a flat smooth stunning blue ice. Next the skill of Tom backs the hut over the hole position expertly, the hole in the ice directly beneath the hole in the floor of the dive shack.  With the help of the Challenger blade we shovel some snow around the edge of the shack to seal out wind and blowing snow. Presto - a dive site ready to dive. I was wishing we had some dive gear I wanted so badly to see what was below.

Next we drilled a safety hole about 200 feet away and marked it with the universal Antarctic danger sign, black flags. This hole is an extra escape route just in case something happens to the main hole. Seals often times get in the holes but aren't usually difficult to coax out of the way. 

The last hole of the day was around the corner about 500 ft away. This site has some settling plates from as long as 30 years ago. They were placed there by Paul Dayton to gauge the growth rates of the animals. It is important that we get pictures and video of this long term experiment.

With the GPS as our compass we walk around the fractured blocks in the pressure ridge towards the spot above the experiment. The ice here has cracks, and working or active cracks at that. Tom looks warily as the Challenger is around 30 tons. The cracks here are so active that a mother seal and her newborn have been able to get through the crack and are basking on the ice. The baby is suckling and they both are very active compared to other seals that I have seen. The GPS points us to the spot and Tom decides to give it a go with the drill. Soon he is snaking the Challenger and the drill sled hundreds of meters away where the cracks are smaller. Then he turns and heads for the site. As a final safety check he fires up the Echo drill and bores about 5 2inch holes to confirm the ice is at least 6 feet thick.  10 minutes of grinding, shoveling, gushing and back blading later we have our third hole of the day.

   

 

The auger video

 

Lots of ice chips to shovel

The gush.

The bladed area ready to drill

Backing the hut over the hole

Some of the carps are very creative.

Finally ready for the first dive

Bob over and out.

 

Lets see the next day!