Showing posts with label Pressure Ridge. Show all posts
Showing posts with label Pressure Ridge. Show all posts

Sunday, November 27, 2011

Greetings from Superman's Fortress of Solitude

Sorry for the radio silence from down south lately.  It's been about a week since my last entry.  This is not due to a holiday, it's really due to NOTHING happening here.  Since last Monday midday, we have not flown once. The weather has been awful.  Pretty much snow, blowing snow, ice crystals, snow pellets, freezing fog the works which all adds up to no flying around these parts.

It is also the week of Thanksgiving here, however since we typically have a six day work week and the holiday falls on a weekday--we observed it last night, Saturday night (as well as a rare two day weekend).  The irony of yesterday is that the aviators have all sat around weathered out this week and the planned day off  for the holiday was absolutely beautiful for flying.  Typical Murphy's Law!

I opted to start off the holiday right with a run and did the 5K Turkey Trot Race here. The good news was it was sunny and looked beautiful out.  Beyond that it was c-c-c-c-c-c-c-c-old and windy!
Ready...set...gooble...
Nearing the turnaround with Mount Discovery in the background
Uphill with Ob Hill in the background
The rest is downhill from here!
I think it was around 14 F with around a 30 knot breeze straight uphill on ice.  The good news was I finished, however I won't be using this time for any future race resume or qualification purposes!  Around 200 folks ran and I did finish in the middle of the pack for the under 40 men's group.  The winner ran around a 20:45 time.  I think I would have trouble doing that on pavement downhill let alone here. Next year I get to change groups to the over 40.  Look out!

The rest of the pre-gorging day was spent out on the sea ice.  The recreation folks put together the first organized tours of the pressure ridges with a mountaineer.  These monoliths are amazing.  The forces of nature are amazing and beautiful.  Its like getting to watch plate tectonics in high speed (i.e. over weeks versus 100 million years).

My immediate takeaway walking among the troughs and peaks of these frozen 25' waves was I know where the writers for Superman came up with the idea for his "Fortress of Solitude"! 
From the comic...
...to reality!

Fire and Ice! Pressure Ridges with Mount Erebus in the background
 The beauty here is amazing.  Pictures are pretty, however hardly do justice to the reality walking through this ice field.

The ice is truly blue.  Nothing touched up on these at all.
A wall 20' of lifted blue ice

A crevasse runs through this ridge
 These ridges are in constant motion.  Tidal forces act upon them daily.  As the cracks form, seawater floods into the voids, freeze and cause uplift.  This in combination with the Ross Ice Shelf flowing into this transition zone causes a mangled mass of blue and white beauty.

Erebus frames by two ridges
Flags mark the safe route.  Wander off and you may slip into a hidden crevasse 

The other beauty of these ridges is that they attract marine wildlife.  These crack do the work for the seals so they do not have to grind their way through the ice to find a breathing hole.  Weddell Seals were the mammal of choice today as we walked through the lazily snorted and rolled over, caring less that we were interrupting their sun bathing.
Life among the ridges.

Huh? Wha? Oh, back to sleep now.
A skua joining in the fun, looking for a spare scrap of fish
Zzzzzzzzz.
A look back through the ice field at Mount Terror as we walk back to Mcmurdo.
I couldn't have imagined a better Thanksgiving down here than what I did.  Lots of fun.  While I wish I was home to spend it with family and friends, this will suffice for now!  Back to the work week.  Hoping for some better weather!   Some neat projects are about to start so I can't wait to check them out and share what I can.

Talk to everyone soon!  Happy Thanksgiving!

Saturday, November 12, 2011

What's a Pressure Ridge?

Shockingly there isn't much shopping down here.  That's a good thing.  However, there still are a couple places on the continent albeit limited.  Nearby is one of the locations outside of town here at Mcmurdo.  Our Kiwi neighbors at Scott Base are a short 3 mile hike away so up and down an icy hill we went in search of Christmas presents and a diet coke. 

Fortunately we walked because we didn't have any New Zealand dimes.
As you approach Scott Base one of the most amazing features right at their location is the sea ice / shelf ice confluence.  Where the two meet is a dramatic scene of the forces of Mother Nature at work with the formation of mangled ice and pressure ridges for miles. So just what is a pressure ridge?
Scott Base and the pressure ridges from a shot I took last season flying.  Mt Erebus in the background.
It's an ice formation typically found on large expanses of sea ice during the winter. In the most basic sense, a pressure ridge is a long crack in the ice that occurs because of repeated heating and cooling on the surface of the ice in addition to the tidal forces and flow of the ice shelf towards the sea.
Mangled Ice


Looking Back at Erebus

A handful of Weddell seals coming up for some sun through breathing holes created by the ridges
In cases of extreme cold, ice will shrink in volume like any other solid, opening up cracks in the surface that are completely frozen over. The cracks quickly fill with water and freeze again, but when the temperature rises later, the ice expands and forces itself upward along the lines of the crack, in much the same fashion that plate tectonics creates mountain ranges, albeit on a much smaller scale. 


That's today's lesson folks.  It was a success in it was a great 5-6 mile hike, I found a diet coke, got a great little Christmas ornament and saw some beautiful and twisted ice.  


Happy Veteran's Day to all my fellow brethren past and present.  Thank you for yours and your family's sacrifices.  Now back to my Saturday.  Cheers!