Town is starting to fill up with people and get busy.  I’m still scanning drawings.  There is still a bit of sunset over the Transantarctic Mountain Range at night.  I’ve just moved to a different dorm with my friend Emily and we’ve actually got a pretty large room for us and all our friends to visit.  When winter-over friends leave, as they do this time of year, they give you food, furniture, room décor, half finished bottles of booze.  Our room is the coziest I’ve been in so far.  Yes, yes, for a silly dorm room.   

Here is an aerial view of town with some of the places I go.  The commute is not bad.

An evening view of town early October from half way up Observation Hill.

A few weeks ago, I went to a training class to learn about working and traveling out on the sea-ice outside of town.  As a recap, McMurdo is at the end of a peninsula on Ross Island and I am on solid ground here.  Just outside of town, McMurdo Sound is covered in about 4 to 8 feet of ice for most of the year.  There is a permanent ice shelf several more miles away to the east and south which is similar to the sea-ice, but it is much deeper and a permanent fixture of the landscape.  The nearby sea-ice builds up over winter and some of it will start to melt and break up in December and January.  Currently, there are planes landing on the sea-ice and several roads leading to science camps studying seals, penguins, or using underwater robots to study the ocean. 

The sea-ice is carefully monitored for quality of ice, temperature, thickness, and cracks by professional surveyors as well as field safety personnel (survival/mountaineer guides).  There are established roads and camp locations which makes it easy to study and anticipate the seasonal patterns and changes of the ice.  Weather, nearby land or ice masses, and ocean currents all affect how the ice moves in this region.  Some of the ice completely melts away, especially aided by the end of summer ice-breaker ship that breaks open a channel for ship access to McMurdo.  This ice will refreeze for the next year being very strong and even throughout (the shipping channel eventually refreezes into the following year’s sea-ice runway).  Some of the sea-ice melts and weakens, but not completely.  This ice is a bit more temperamental and uneven due to subsequent years of ice melting and freezing on top of each other- not the best conditions for roads or a runway.    

I couldn't find the most recent map, but here is an example of how the surrounding area gets used and monitored. 

Although the professionals know what they are doing, it is important for the rest of us to be educated if we are going to be working or traveling on the sea-ice.  The heavy vehicle operator that grooms the nearby roads has this training to assist in the monitoring of those areas, as does the driver who takes a group of people out for a recreational trip, or the carpenters that go to fix a door on a science camp hut.  The safety record out on the ice is really good and incidents are rare due to the amount of attention to these areas. 

In addition to the classroom presentation on what to look for and experience on the sea-ice, we also went on a trip about 10 miles away to “profile” a known, seasonal crack in the sea-ice.  Fun!  To profile a crack you need to be able to drill holes into the ice and measure its thickness, measure the width of the crack, and use a rule-of-thumb formula to determine whether it is safe to cross the crack.  I first imagined these cracks to have straight up and down sides to them and maybe they were 4” wide, maybe they were 12” wide. Not all cracks are alike, and they can be really subtle or really pronounced. 

Crack.

Shoveling out the crack to see the whole profile.

At this time of year, the cracks will have several layers to them as they continue to re-freeze within the crack, creating a stepped effect.  The crack is passable by vehicle if the center, shallow part of the ice is greater than 30” deep and has a width less than the width of 1/3 of the vehicle’s wheel or track width. 

Hand drilling through the ice until you hit water.

Gas powered drill goes faster.  We got about 36" of ice in the middle of this crack. 

The drills are either hand cranked or can be powered with a small gas engine.  The 2” wide “bits” are not sharp except for the very end, and they drill through the ice easily with a little elbow grease.  The lengths of the bits are 1 meter and you can connect the lengths together when you absolutely need to know the entire thickness.  The tape measurers are weighted to sink into the water and have two different pulls.  Pull the tape itself and the weight will stop on the underside of the ice, easily for reading the tape.  Pull the cable and the entire thing will come back up through the hole.

After our class profiled the known crack, we drove out further (it was determined safe!), off the established road to get some ice measurements where a science group studying seals wants to travel in this area (to get to more seals).  We drilled about 10 more holes and the ice measured to be about 54” deep.  That was just some basic info and the field safety professionals will come out soon to investigate further.  The trip was fun and it was fairly warm out there with little wind.  The trip overall was about 4 hours as it is slow going in a large vehicle over the ice. 

Inaccessible Island

 More drilling.

The ice is about 2 feet below drifted snow in some locations.

Ross Island's Mount Erebus and me.