Ice Stories: Dispatches From Polar Scientists » pressure ridges http://icestories.exploratorium.edu/dispatches Mon, 15 Nov 2010 20:40:36 +0000 http://wordpress.org/?v=2.9.2 en hourly 1 Back in the Air http://icestories.exploratorium.edu/dispatches/back-in-the-air/ http://icestories.exploratorium.edu/dispatches/back-in-the-air/#comments Mon, 19 Apr 2010 17:24:52 +0000 John Whiteman http://icestories.exploratorium.edu/dispatches/?p=2303 KAKTOVIK, ALASKA– On April 8th, I woke up at 315am, caught a shuttle to the Denver airport, and boarded a plane for Seattle. After additional layovers in Anchorage and Deadhorse (Prudhoe Bay), I landed in Barrow, Alaska, at about 530pm. It was around -5 degrees (Fahrenheit) with a light wind. I had envisioned a return to wintry conditions, but it was still a shock to go from the humid heat of Buenos Aires in the summer, to early spring in Wyoming, to late winter in the Arctic.

I met up with the team of researchers from the US Geological Survey who had been performing polar bear captures out of Barrow already for two weeks. That evening, after looking over our gear and getting caught up, I went over to see friends who recently moved to Barrow from Wyoming. It was great to hear about their new life in the area; moving from the mountains to the tundra is certainly a big change.

The next day I began flying in the helicopter for captures. We started in Barrow, fueled up in Deadhorse, and ended the day in Kaktovik, near the Canadian border – we covered almost the entire northern coast of Alaska. Since then we have been based out of Kaktovik, and we have had good weather and have been flying a lot.


It is great to be back out on the sea ice. Although I am out of place here, I really love this environment. In this picture we landed on a small pan of ice about twenty miles from shore; the pan was surrounded by pressure ridges and rubble from ice sheets smashing into each other.

The captures have been going well. We caught the largest bear I have seen, an adult male who weighed 1,147 lbs (I am not sure what the largest bear caught in the southern Beaufort has weighed). His neck was several times the size of my waist, and I could not fit both hands around his snout. It took several people to position him for measurements. We have caught several bears which were sampled in 2009, giving us excellent data on changes over time in the same individual.


We have also caught a lot of cubs-of-the-year, or COYs, including this litter of three. Cubs are born around January 1st. Litters of three are fairly uncommon for polar bears in Alaska, and usually include one cub that is noticeably smaller than the others – in this picture, the cub in the middle only weighed 12 lbs, nearly 10 lbs less than the other two.
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Pressure Ridges http://icestories.exploratorium.edu/dispatches/pressure-ridges-2/ http://icestories.exploratorium.edu/dispatches/pressure-ridges-2/#comments Fri, 08 Jan 2010 00:24:48 +0000 Mark Krasberg http://icestories.exploratorium.edu/dispatches/?p=2090 MCMURDO STATION, ANTARCTICA– Today I visited the (New Zealand) Scott Base. The New Zealand base is next to some spectacular pressure ridges, which are caused by tides where the sea ice meets the land – the ice literally buckles and rises upwards. While I was there I was invited to walk around this spectacular sight. (You have to be invited by a member of the New Zealand base.)


Members of the New Zealand base use flags to map out a safe route. The ice was starting to get soft and they were about to close down trips, but luckily the paths were still open.

Where the sea ice meets the land, the ice buckles and rises upwards under tidal forces, forming these pressure ridges.

Pressure ridges with Mount Erebus in the background.

Another view of the pressure ridges.

During the trip we encountered a Weddell seal lying close to the path. It was cute.

That’s me posing with the Weddell seal.

In the background, you can see a new feature on the Antarctic landscape: Scott Base has built three windmills for power.
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The Power of the Wind and Tides http://icestories.exploratorium.edu/dispatches/the-power-of-the-wind-and-tides/ http://icestories.exploratorium.edu/dispatches/the-power-of-the-wind-and-tides/#comments Thu, 26 Nov 2009 03:09:56 +0000 Heidi Roop http://icestories.exploratorium.edu/dispatches/?p=1992 MCMURDO STATION, ANTARCTICA– We have been here a week now and the cargo is packed and loaded. Several planes have been able to get cargo out to WAIS and now all of the science crew and drillers need to get out to camp! Things are finally starting to look up. In the meantime, we have been having a grand time exploring the hiking trails, coffee house and entertainment that McMurdo has to offer (think craft room, gym, exercise classes, movie nights etc.)! Many of us are trying to stay healthy by going on runs, skiing, and hiking. We have had great weather (~15-20 °F) with sunny skies so that certainly provides the motivation to get out and have fun while we wait to get out to WAIS Divide. One of our adventures was over to the pressure ridges near Scott Base, the home of the Antarctica New Zealand program.

This short video sums up pressure ridges. The pressure ridges we explored here form where a large mass of sea ice buckles under pressure as it makes contact with land (in this case, Ross Island where McMurdo Station and Scott Base are located). The wind, tides, and sun are all variables that constantly change these ridges. With Mt. Erebus looming over the station, the views were quite dramatic. Surprisingly, every view along our ~2 mile walk seemed different! It was like walking through a park of ice sculptures! Like identifying shapes in clouds, we were able to see a dog, person, peace sign, and set of waves. I hope you enjoy this short video with photos from this little adventure onto the ice!

Music by Wayne Grim.



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Pressure Ridges http://icestories.exploratorium.edu/dispatches/pressure-ridges/ http://icestories.exploratorium.edu/dispatches/pressure-ridges/#comments Mon, 12 Jan 2009 22:16:09 +0000 Mark Krasberg http://icestories.exploratorium.edu/dispatches/?p=1490 SOUTH POLE STATION, ANTARCTICA– Before I left McMurdo, I got a tour of the pressure ridges near Scott Base (the New Zealand station very close to McMurdo). The pressure ridges are formed by tidal forces — there is a thick sheet of sea ice which meets the land, and tidal forces cause the ice to buckle. Members of the New Zealand base use flags to map out a safe route, and we were allowed to walk around these marvelous ice formations one evening. Our guide was Peggy Malloy. The trip was a lot of fun!


Aerial view of McMurdo Station (US – brown buildings) and Scott Base (NZ – green buildings).

View of Scott Base from the pressure ridges.

Pressure ridges.

Flags to map out a safe route through the pressure ridges.

Another photo of these marvelous ice formations.

Me and my guide, Peggy Malloy.
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Made it to Antarctica http://icestories.exploratorium.edu/dispatches/made-it-to-antarctica/ http://icestories.exploratorium.edu/dispatches/made-it-to-antarctica/#comments Fri, 26 Dec 2008 22:04:01 +0000 Mark Krasberg http://icestories.exploratorium.edu/dispatches/?p=1401 SOUTH POLE STATION, ANTARCTICA– En route to Antarctica, I spent three days in Christchurch. The weather was nice – a few of the IceCubers played croquet next to the Botanical gardens.


The Christchurch Botanic Gardens, New Zealand.

The Croquet Club, Christchurch.

On Dec 9 we were scheduled to take a South African Hercules to McMurdo but ended up flying on the massive C17 “Globemaster” instead. The C17 was going to make an aidrop to “AGAP” after it dropped us off in McMurdo. You can see that the air-drop cargo was all ready to go (there is a parachute on top of each piece of cargo).


The C-17 ready for Airdrop.

During the flight I saw a lot of pack ice, and also got a nice photograph of the Antarctic coastline. We landed at Willy field (a runway on the sea ice). It was a nice day and you could see Mount Erebus in the distance (an active volcano).


Pack ice from the air.

The Antarctic coastline.

The C-17 ‘Globemaster.’

After being debriefed and getting our room assignments I took the Terrabus over to Scott Base (the New Zealand station). From there I could see the pressure ridges, and also the Happy Camper (Antarctic survival training) folks in the distance.


Having landed at McMurdo Station with Mt. Erebus in the background.

Scott Base pressure ridges, Terrabus and Happy Camper at foot of Mt. Erebus.

I knew that Mary Miller and Lisa Strong from the Exploratorium were standing there next to the two Scott Tents. The Happy Camper school was taking place at the foot of Mount Erebus. In the photo above, you can see the Terrabus between the pressure ridges and the Happy Camper school.

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The Eve of Discovery http://icestories.exploratorium.edu/dispatches/the-eve-of-discovery/ http://icestories.exploratorium.edu/dispatches/the-eve-of-discovery/#comments Fri, 12 Dec 2008 18:08:05 +0000 Adrienne Block http://icestories.exploratorium.edu/dispatches/?p=1316 MCMURDO STATION, ANTARCTICA– It has been a rollercoaster week. This time last Friday, I would have been desperate to get my hands on some data. I was the kid that asks for homework. I was aimless and lost without it. Feeling like everyday you are just biding your time is harder when you know that time will soon become too precious. Now, I have spent the week slaving over the data I cravenly awaited. And I’m definitely not asking for anymore homework! In fact, I could use a Spring Break! Mostly I have been making little changes to the software so it can handle the volume of data we are bringing back from the flights. In about 40 seconds, our system collects 457.8MB of just radar data. That’s equivalent to almost 8 hours of music. Handling the data would be easy enough if our flights lasted 80 seconds…. But they are 2,4, even 6 hours long. Radar data comes in massive chunks!


Because being at high altitude can make some people sick, the science team has to be trained on multiple parts of the airplane’s science equipment.

During June this year, we tested our radar system in Greenland. We flew over the Greenland Ice Sheet, collecting data to image the ice down to 2.5 km (1.6 miles) below the lake-spotted surface. Now in Antarctica, we face the challenge of imaging more than 4 km of ice…. That’s 2.5 miles of frozen history between our science team and the Gamburtsev Mountains we came here to study! Because we have to reach further into the ice, we have more data than ever coming back after each flight. There’s so much data that the system chokes on it and gasps, “Help me, Adrienne. Help!”

I have escaped the office a few times this week. I got to go on a tour of the pressure ridges that form between the flowing ice of the Ross Ice Shelf and the rock that stands firm against it. And just last night, I escaped to Scott Base, the Antarctic Base that belongs to New Zealand, for some retail therapy. My Scott Excursion really took my mind off of the software for a while and had me refreshed and ready to go back to Radar World this morning. Not to mention I am well stocked on wooly base layers to fight the cold.


View of Scott Base from the Pressure Ridges.

An interesting formation in the Pressure Ridges. What do you think it looks like?

Today, I feel the same way I do when I am at the top of the big hill at the beginning of the ride. There’s that moment when you lift off your seat before powering down the steep hill, screaming your head off. I have been living there, in that emotional suspension for 3 days. Part of my jitteriness the last few days is undoubtedly rooted in the fact I’ll be going to the South Pole on Monday. According to our medical briefing, that means I’ll be perpetually short of breath, having trouble sleeping and going to the bathroom about every 20 minutes for 2 days…. The anticipation is almost too much to hold in! I have been to 10,000ft elevation before but that was after living at 6,500ft above sea level for 5 weeks… and that was in Utah. The transition from sea level here in McMurdo to 10,000ft is such a surprise to the system that everyone is prescribed a medication to help our bodies adjust to the lower oxygen levels. On top of that, we all have to fight off the adrenaline brought on by the fact we’re in Antarctica, at The South Pole, at 10,000ft—no offense to Utah, but it doesn’t compare! Just in case we don’t adjust to the elevation, everyone has been learning tasks outside their specialty. Hopefully, if someone gets sick, we’ll be able to keep the science moving forward, even if at a slower pace.

In the end, it’s not just where we’ll be a week from now. It’s what we’ll learn. The Gamburtsev Mountains have been enigmatic since their happenstance discovery in 1958. Soon, we’ll know them in a way only dreamt of until now. The people on this science team will learn more about the Mountains than the rest of the world has compiled in the last 50 years. This is the Eve of Discovery.

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