A Hike and Tour of the Pressure Ridges

A Hike and Tour of the Pressure Ridges

A group of WISSARD’s went out early this morning with a guide, Todd, to view the pressure ridges close to Scott Base.  Pressure ridges form when the sea ice collides with the glacial ice of the ice shelf.  The pressure of those two masses of ice coming together makes some of it lift up into unique and beautiful ice/snow formations.  These almost look at times like ice waves.  We spent several hours out on the ice hiking and observing seals.

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Weddell seals come through the cracks in the ice or a melt pool (ice that is now melting on our warmer days) and lounge around on the ice.  The first seal we saw was quite a poser!

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They have a sweet face and it almost looks like they are smiling!

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The seals would wake up occasionally and wiggle their tail flippers.  They’ll also scratch themselves with their arm flippers.  Our WISSARD videographer, Dave, filmed a lot of the seal behavior and the ice waves of the pressure ridges throughout our hike.

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It was a cloudy day today (warm, about 35 degrees F) and the ice took on a rather blue quality.  Some of the melt pools freeze back up when temperature drops.  The photo below shows how beautiful these frozen pools can be.  Ribbons of blue and white curve gently through the frozen pool.

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In other areas, we’d see icicles hanging down off of huge ice shelves.  The patterns and shapes of these pressure ridges change every day.  Todd mentioned that he’s led several hikes here now and each time the pressure ridges have looked completely different.

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Todd went through a special training session to be able to lead these hikes.  He was always ready to alert us about cracks in the ice.  The flags mark the route and also show where danger might exist.  If two flags are together around a crack, they can help tell how much that crack is spreading or closing over a given number of days.

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The flags shown here mark the end of the side trail we took to reach this frozen pool.  I thought the colors and shapes were fantastic, and I liked the cloudy weather instead of a bright glare on the ice and snow.

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As we hiked along, we could see Scott Base not far away.

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Here are a few more photos, and be sure you read all the way to the end of this post.  I have a special short video to share!

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This picture illustrates how tall the pressure ridges can be compared to my height.

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Often we couldn’t get that close, due to the danger of cracks and uneven ice.

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Dave hauled his heavy camera to get some incredible shots.  I can’t wait to see those images and the videos.

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Later today there was a McMurdo “event” of sorts.  Many people in the town came out both yesterday and today for a blast taking place near the ice pier.  It was like a social event!

Right now they are freeing up ice around the pier with explosions, and workers will gently move the ice pier closer toward the road.  The dirt you see on the flat platform is actually covering a thick layer of ice.  Creating the ice pier takes a ton of work!  It has to be up to 22 feet thick and strong enough to support container trucks. The McMurdo ice pier is approximately 800 feet long and 300 feet wide.  Usually an ice pier has a life span of 3-5 years and once it is no longer stable it is towed out to sea, cast adrift, and a new ice pier is created.

When the re-supply ship comes in later this season (February), it will dock next to this pier and cranes will off-load heavy containers while every truck and vehicle possible will help deliver materials and equipment to places here in McMurdo.  Here is a short video of today’s blast….it was SO loud, which I am not sure you catch on this video.

13 responses to “A Hike and Tour of the Pressure Ridges

  1. What a neat excursion! Hearing about you walking in and around the pressure ridges reminded me of Jon Krakauer’s book, “Into Thin Air.” I know he talked about the numerous crevasses on Mt. Everest with regards to how deep, and dangerous, they are. This leads me to two questions regarding those. Are the cracks fairly easy to see, or were you solely relying on the flags to determine where those were at? Also, how deep were the cracks (is that what makes them cracks, versus a crevasse?) I guess that is three questions. I imagine that it must be pretty hard to navigate through that area without those red flags – especially if the landscape is always changing. Could you hear ice cracking alot. I imagine that it would be like trying to hear a branch fall in the forrest. You see the limbs all over the ground, but rarely see them fall. With the landscape changing, and the ice colliding with each other, you would think that occaisionally you could hear the ice break apart. I guess this might happen more at night though when the temperatures drop and the ice expands. Who knows, just thinking out loud. Let me know your thoughts, as I am fascinated by all of this. I find it cool that you are witnessing a much smaller scale of plate tectonics which attributes to forming the highest places on Earth (and the hottest if you are in a volcano. Not often can you see such a phenomenon happen right before your eyes.

    • My goodness that was a long post with heaps of questions. Let me answer as many as I can. First, the flag routes are changed often, as the ice changes. The cracks are sometimes easy to spot, but people trained in snow/ice science review the routes regularly and make adjustments as they spot weak areas. I felt very safe, because I know this area is checked routinely.

      It was hard to navigate at times because in some areas the snow is packed down and is more slippery. In other places it’s very uneven. When the light is “flat” like yesterday, it’s hard to see the definition in the snow and ice….making the route more dangerous unless you take your time. Everyone was taking so many photos that we didn’t move too quickly anyway! 🙂

      When I was in the pressure ridges six years ago, I heard some cracking noises, but I didn’t yesterday. It would be cool to set up a time lapse video camera and record the changes and sounds in the pressure ridges. In fact, I’m sure someone’s done that.
      Thanks for writing, Matt. Love you! xo Betty

  2. SO neat! I loved the blast. Have you ever been on an excursion where things became unsafe? Either the weather quickly became severe or your walking path was not secure? You mentioned the caution flags which hopefully help avoid most of these scenarios from happening.

    • Hi Linda,
      I’ve not been in a situation that was dangerous, and much of that is because I always follow the flagged routes and directions given. Weather was an issue during Happy Camper, but we had snug tents to stay in, even if it was windy and cold. Our instructors were close by, and in case of emergency we were in good hands. The caution flags are very important, and people who have not paid attention to those have suffered some dire consequences. I plan to stay very safe! Love you! xo Mom

    • What a beautiful snow/icescape it was. I like to see how the pressure ridges change each time we drive by them on the way to the WISSARD test site. I might even get to see them break apart when the sea ice changes later in the season….January or February. Miss you, dear friend! Stay in touch!

    • Hi Mal, You would really like this hike! It’s not Sterne’s Woods, but it’s awesome! Stay in touch!

  3. Hi Betty!
    Ella, Aiden and I were checking out your blogs tonight. It sounds like you are having an amazing time! Ella was very excited to see the seals. She couldn’t believe how close you were. We can’t wait to read all the others! We miss you!!!

    Katie

    • Hi Katie….It’s SO nice to hear from you! I miss you! Tell Ella that we had to keep a safe distance from those seals and I zoomed in with my camera. If the seals start to change their behavior, we have to leave that area. They are HUGE animals and very lazy looking, lounging there on the ice. Keep in touch! Happy Holidays!

    • Hi Seif,
      Yes, those seals are very lazy. Those were adults that we saw. I’m having a very good time and learning a lot. Keep writing!

    • Hi Trinity,
      I miss you, too! I’m glad you enjoyed the photos. I try to use lots of photos with each blog because they help tell the story. I’ll be safe and I can’t wait to come back and teach in my classroom! Happy Holidays!

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