Say “Helo” to the Sea Ice: Helicopter Flight Over McMurdo Sound

Helicopter taking off from McMurdo
A helicopter taking me to New Harbor on Nov. 21st lifts off from McMurdo. Riding in a helicopter never got old. Photo: Elaine Hood.
New Harbor from helicopter
The New Harbor team gathered outside the Jamesway huts to see me off when I flew out a few days later.

To travel to the four field camps I visited during my stay in Antarctica I took a total of eight helicopter trips. Traveling by “helo,” as they say there, or watching them take off, land, and pick up sling loads never got old. I don’t think it was just because I was an Antarctic newbie; even at the field camps where helicopters took off and landed a few times a week, or in the case of Lake Hoare, a couple of times a day, camp residents would stand at the hut window or just outside the door to watch.

Since all fresh water, fuel and food is brought into the field camps, and all waste is packed out, the helo pilots are busy all day during the field season. And when I say all waste is packed out, I mean everything: gray water (water left from washing hands, faces, and dishes), human waste (metal drums for the pee, five-gallon plastic buckets for the poop), trash (sorted into recyclables, non-recyclables, and food waste). By treaty, all traces of human presence are to be removed from the environment, which as you can imagine, demands a lot more thoughtfulness in sorting and disposing of trash than we’re used to, not just in the field, but at McMurdo, too. Heavy items are suspended under the helicopter as a sling load. Laura Von Rosk has posted a short video of sling load take-offs from New Harbor on the Bravo! 043 Facebook page (see December 9, 2015 post).

Helicopters take off and land vertically, which is a different sensation than the headlong forward motion of an airplane liftoff. On December 16th, a brilliantly sunny day, I shot this video of the helo take off (posted on YouTube) from McMurdo Station on the way to Blood Falls in the Dry Valleys. (I’ve already discussed Blood Falls in the previous post.) The video starts just after the helo has risen off the ground and is turning around to head out over the sea ice. Mt. Discovery is in the distance.

Helmets are equipped with microphones so passengers can communicate with the pilots during the trip. McMurdo pilots like pointing out the sights. On this trip, returning from New Harbor, I was sitting in the back seat of a four-seat helicopter.
Helmets are equipped with microphones and earphones so passengers can communicate with the pilots during the trip, because helicopters are noisy. That’s one of Mike’s colleagues pointing out the sights on the return trip from New Harbor. I was sitting in the back seat of a four-seat helicopter.

Mike, the helo pilot that day, knew that I was interested in ice, and asked if I’d like to see the recent changes to the edge where the sea ice meets the ice shelf. Well, yeah! The last time I’d flown across the sea ice to the Dry Valleys had been almost a month before, and it was indeed different. Meltpools filled with blue water streaked the surface of the ice shelf, including a stream flowing to the sea ice. The rest was a corrugated pattern of white ice and snow outlined by dark brown sediment that had blown there from the surrounding mountains, carried by fierce Antarctic winds.

Sea ice meets ice shelf, McMurdo Sound
The Edge: On December 16, Mike showed me the recent changes in the edge where the sea ice meets the ice shelf. Mt. Discovery is in the distance.

We flew over a large crack in the sea ice that was remarkably regular in shape: three fairly straight segments at close to right angles. When I showed this photo to glaciologists Doug MacAyeal [pron. mac-hale] and Ian Willis, they told me that it was the result of movement analogous to that of the tectonic plates of the earth’s crust, where forces were pulling the sea ice away from the ice shelf, creating the two cracks that are vertical in the photo. The horizontal crack had then opened between those two cracks, connecting them; Doug pointed out how its edges were jagged, rather than clean.

Cracks in sea ice, McMurdo Sound
Zigzag: This crack resulted from ice dynamics where the two parallel cracks separated and the horizontal one formed between them.

As we headed across McMurdo Sound toward the Kukri Hills and the Dry Valleys a low white object appeared in the distance, resembling those gift boxes they give you at a department store. It was a huge tabular iceberg that has been frozen in the sea ice for at least a few years, according to another of the helo pilots. I had flown over it once before, on the way to New Harbor.

Iceberg stuck in sea ice
At a distance, the iceberg stuck in the sea ice of McMurdo Sound looks like a department store gift box.

As we got closer, the immense scale became evident. What looked like a perfectly flat top and planar sides from a distance was inflected with vertical ridges and horizontal lines. Tabular icebergs have flat tops and steep sides, and are created by breaking off from ice sheets or ice shelves, so presumably this one was once part of the ice shelf.

Tabular iceberg, McMurdo Sound
Approaching the tabular iceberg. It is not as rectangular as it appeared from a distance. That’s part of the helicopter in the right foreground.


Tabular iceberg, McMurdo Sound
And an even closer view of the side.

At one corner, a huge chunk is poised to fall. The helo pilots have been watching it all season: “I’d love to be flying over it when that happens,” one told me. That will be quite dramatic when it gives way and tons of ice come crashing onto the sea ice, though odds are nobody will be around to see it. The McMurdo helicopter pilots enjoy the ever-evolving panorama beneath them as a perk of the job. On my last flight I asked the pilot about that and he said, absolutely — flying over other locations can be very monotonous by comparison.

Tabular iceberg, McMurdo Sound
Leaning Tower: One day that enormous chunk will come crashing to the ground.

As we began to enter the area of the Dry Valleys, we saw a variety of other patterns in the ice below: an area where it had broken into large, roughly rectangular sheets; turquoise melt pools and a stream between sparkling white ridges; and a long blue melt pool with parallel sides as if someone had built a canal there. The way the sea ice could fracture along long straight lines into almost rectangular shapes intrigued me.

Sea ice formations, McMurdo Sound
Roughly rectangular blocks of ice are outlined by turquoise melt water. Beside them, more irregular patches resemble a flagstone path.
McMurdo Sound sea ice
Further along were these gorgeous turquoise and white patterns as we headed between the hills. The helicopter rotor is a blur in the top center.
Sea ice stream, McMurdo Sound
That view gave way to narrow streams and a few melt pools.
Melt pool in sea ice, McMurdo Sound
A sea ice “canal” with parallel sides that are so evenly spaced it looks manmade.

Our helo flight to Blood Falls turned and crossed over the steep gravel Kukri Hills. On the other side of the valley, you could see the Canada Glacier spilling down to Lake Fryxell, which was on the right, and Lake Hoare, on the left. We landed briefly at Lake Hoare to drop off some supplies before continuing to Blood Falls. That was my first view of the field camp where I would return a few days later and spend five nights. If you check out my earlier blog post about Lake Hoare, you’ll see ground level views of the camp. From the air, it’s clear how tiny the main hut, lab buildings and tents are in relation to the Canada Glacier.

Helicopter view of Canada Glacier
Flying over the hill, the Canada Glacier in the distance, with helicopter antennas in the right foreground.
Canada Glacier, Aerial View
The Canada Glacier comes into view, with the frozen surfaces of Lake Fryxell to its right and Lake Hoare to its left. The light was perfect for capturing the rugged texture of the ice falls further uphill. A few days later, I hiked to the bottom of the lower ice falls, over the top of the glacier, and down to Fryxell. I’ll write up that trip in a later blog post.
Lake Hoare field camp
In this aerial view of the Lake Hoare camp, you see a portion of the Canada Glacier looming over the main hut, three labs, smaller outbuildings, and if you look really closely (click image to enlarge), small tents where the scientists and camp personnel sleep. For a ground level view see my earlier post.

The final photo in this sequence was taken just before we got to Blood Falls, looking into the Taylor Valley toward the distinctive striped hills resembling chocolate sandwich cookies, yet another unexpected sight in a trip that was full of them.

Taylor Glacier, Dry Valleys, aerial view
Sandwich Cookies?: The Taylor Glacier is bordered on one side by distinctive striped hills. Lake Bonney is in the foreground. The hill in the foreground blocks the view of the west lobe of Lake Bonney and Blood Falls, which are on the other side.





Under Pressure Ridges

Scott Base pressure ridges
The Scott Base pressure ridges present an undulating landscape of unending variety. In the center of this photo is a melt pool.

If you’ve been following this blog, you’ve been introduced to the pressure ridges near the Double Curtain Glacier, which is across McMurdo Sound from McMurdo Station in the New Harbor/Explorer’s Cove area of the Dry Valleys. During the seven weeks that I was based at the US Antarctic Program’s McMurdo Station, I also made two trips to visit the extraordinary pressure ridges at Scott Base, which neighbors McMurdo and is operated by New Zealand’s Antarctic program. If you’ve seen Anthony Powell’s excellent documentary film, Antarctica: A Year on the Ice, you may have noticed the Scott Base pressure ridges among the time-lapse photography sequences.

Observation Hill view of Scott Base
From the 754-foot-high summit of Observation Hill at McMurdo Station, you can see an aerial view of the Scott Base pressure ridges, including the undulations in the ice shelf that have helped form them. The little black dots on the ice a little left of center are Weddell seals. (Click on photo to see enlargement.) I also photographed the prominent formation in the center from the ground (next image) and made a 3D file of it (shown further down in this post):
Scott Base pressure ridge
This formation is large enough to stand out even from the top of Observation Hill (see panoramic photo above). I also made a 3D file of it from 53 photographs taken while walking around it (scroll down further below).
Scott Base pressure ridge
Scott Base pressure ridge with Scott Base in the background.

In Antarctica, the interaction of permanent thick ice shelf (that constantly floats atop the sea), sea ice (that is subject to melt cycles, and some years even melts to the point where it breaks up and floats out to the ocean) and the stationary rock of the coastline, can cause the ice near the shore to buckle and push up chunks into formations called pressure ridges. The pressure ridges are dynamic and constantly changing due to the action of the forces described above along with the 24-hour summer sun. Summertime temperatures at McMurdo when I was there mostly stayed in the 15 to 30 degree Fahrenheit range, and only a few times that I recall got into the upper 30s (and once a balmy 43 degrees — a few of the young guys took advantage of that heat wave to walk around in shorts!). But even in below-freezing air temperatures, when the sun beats down on the ice, it softens and sometimes melts. Then there are icicles, large chunks splitting off and falling, or gravity sometimes causes a chunk of snow to bend and flop over like a draped cloth.

Scott Base pressure ridge
By November 30th, long icicles had formed beneath this this sheet of ice.
Scott Base pressure ridge
The underside of this large chunk of ice was a deep blue and decorated with icicles. In the background are the green buildings of Scott Base.
Scott Base pressure ridges
A thick mat of softened ice can bend like a draped cloth (lower right) and form graceful curved shapes.

Because of the ice shelf and sea ice dynamics, there are also cracks in the ice and melt pools on the surface that widen and deepen as the air warms (one of those was prominently featured in my post about Mt. Erebus). So there is a small window of time from November until mid-December when it is safe to walk out on the ice to get close to the pressure ridges. The McMurdo Recreation Department leads evening tours for the workers and others in residence there during that rare period. I went on two such trips, on November 24th and 30th. These photographs are, essentially, documentations of ephemeral formations: even though these photo sessions were only six days apart some of the ice had already changed in that brief time.

Scott Base pressure ridge
Another spot where the snow has drooped over like a towel on a rack (upper center).

Where there is a nice-sized crack in the sea ice near the shore of McMurdo Sound or one of its islands, chances are you’ll find a group of Weddell seals laying out along it. Cracks give them a head start in chewing out a seal-sized hole in the ice where they can haul themselves out of the water for a break from non-stop swimming and foraging for food. I’ve never seen an animal that sleeps more soundly than a Weddell seal! They also give birth and nurse their pups on the ice. At least one of the Scott Base seals had a pup:

Weddell seal and pup at Scott Base pressure ridges
Baby Seal!: A Weddell seal and her pup chill out at the Scott Base pressure ridge.



From the shoreline, the ice formations are flatter and some have straight lines and more angular profiles:

Scott Base pressure ridge
Looking out from the Scott Base shoreline at angular pressure ridge formations. On the horizon is Willy Field, one of the airstrips that serves McMurdo and Scott Base. It’s probably about a 15- to 20-minute drive from that spot, i.e., not as close as it looks! It’s pretty much impossible to judge distances in Antarctica. You learn to not even try.
Scott Base pressure ridge
Planar ice formations close up.

From other angles there were other formations to see, as in the two vertical photos below. I also did a few walk-arounds for photogrammetry captures. I’ve processed one of those files for a potential sculpture (horizontal image below those).

Scott Base pressure ridges
Peering through a crevice at the Scott Base pressure ridges results in a puzzling and ambiguous spatial reading.
Scott Base pressure ridges
Another unexpected sculptural ice formation.
Scott Base pressure ridges
A 3D file made from 53 photographs walking around a portion of the Scott Base pressure ridges. I need to edit out a few extraneous forms, but the capture came through mostly intact, with great detail and very few gaps.

At the end of this post is a photograph of another fascinating phenomenon we saw on the November 30th trip to Scott Base: a type of mirage called a fata morgana. It has nothing to do with pressure ridges, but it does have to do with looking across the wide flat expanse of the sea ice toward a distant shore. A young man in our group noticed it first. In a fata morgana, a strip at the bottom of the land seems to be stretched like Silly Putty. This one was subtle, but unmistakable. There are more dramatic examples online. Just search Google Images for “fata morgana Antarctica” or read this explanation.

Fata morgana, McMurdo Sound
Across the sea ice from the Scott Base pressure ridge there was a fata morgana effect that made the bottom strip of the Transantarctic Mountains across McMurdo Sound appear to be stretched into a horizontal band at the bottom. Fata morganas appear in Antarctica when a band of air just above the sea ice is a different temperature than the air above it, causing a temperature inversion and distorted reflection at the horizon. Fun fact: the name comes from the Italian for Morgan Le Fay, half-sister of King Arthur.







Grounded Icebergs Near the Dellbridge Islands

Am I the only one who sees a face on the left?

On December 1st, before visiting the Erebus ice cave, Evan and I went to see some icebergs that are stuck in the sea ice near the Dellbridge Islands. The Dellbridge Islands include Tent Island, Big Razorback and Little Razorback. The iceberg I photographed first is nearest to the island in the group with my favorite name, Inaccessible Island, named by the famous British Antarctic explorer Robert F. Scott because it was hard to reach. Of course, he didn’t have a Haagland tractor, which made the trip much easier. Not that a Haagland is a luxury vehicle by any means, but it’s great for traveling on ice and it gets warm inside. Big Red (as everyone calls the heavy parkas we were issued) comes off when you get in a Haagland. You’ll see the islands in the background of some of these photos. Also nearby was Mt. Erebus, but it’s so huge (over 13,000 ft.) that Erebus seems nearby wherever you go around here. The angle of the sun showed up the large crevasses on its lower slopes.

Crevasses on Mt. Erebus
It was so clear that even from a distance you could see the crevasses on Erebus’s lower slopes.

The plan was for me to circle the iceberg nearest Inaccessible Island, to take photos for a 3D file, which I did. I selected 162 to process and since there were so many, I carefully masked them in the software, which took several hours, and I’m processing the file as I type this. I’m optimistic it’ll come out, because the first stage of processing where I aligned the photos showed a generally recognizable shape, and the second stage, under way now, originally showed it would take a total of 12 hours, but it is now almost 60% finished and the estimated total is down to 7 1/2, so the fact that it’s going faster than the original estimate is a good sign. Stay tuned for the next post…

Iceberg, two kinds of ice
Two kinds of ice, matte and glossy, side by side. Click this and the other images to see larger views.

In the meantime, I’ll share with you photos I took after we left that iceberg and stopped at a spot where we could walk around a couple of smaller ones. One in particular had a lot of drifted snow around it, so I’m not sure if I’ll be able to get a 3D file of the whole thing, but it sure had a wide variety of ice formation and profiles that changed as you walked around it. The photos here show some of my favorite views.

Iceberg in sea ice with melt pool
A little pool of water had melted around one end. Our Haagland vehicle is in the distance on the right.
Iceberg frozen in sea ice
Wind-whipped snow and ice.
Iceberg and drifted snow
The drifting snow had curved into smooth, rounded forms.
Iceberg stuck in sea ice
A slight change in perspective shows a different view than the one above, although you can see the same large forms on the left.
Icerberg stuck in sea ice
But the opposite side of the iceberg looks totally different from the side catching the drifting snow.


Iceberg stuck in sea ice
This is the only shot I’ve included of the smaller of the two icebergs, because it wasn’t as interesting, although the hook-shaped protrusion popping from the top in this view is certainly quirky.


Little Razorback Island
The two smaller icebergs were closer to Little Razorback Island. You can see where pressure ridges have formed near the island.

Erebus Ice Cave: The Sequel

Ice cave
On my second visit to the ice cave, I experimented with indirect lighting and got some otherworldly images.
Mt. Erebus
Smokin’ hot: Tuesday you could see that Mt. Erebus is an active volcano, with a little puff of white smoke rising above the crater at the summit.

Tuesday I went out with Evan, one of the mountaineers on staff here, whose assignment for the day was to take me to any icebergs frozen in the sea ice that interested me and back to the ice cave in the Erebus Ice Tongue. We went in Gretel, the same Haagland tractor featured in my sea ice training blog post, so it was lot easier riding around than driving a snowmobile. Snowmobiles are fun, but they get somewhat less fun when you have to travel for an hour on one — your right hand gets tired from being on the throttle, and it’s obviously colder, too, though aside from inside the cave, it was a nice day with little wind. I photographed three icebergs that are frozen in the ice, so you can walk right up to and around them, certainly impossible when they’re floating because it’s too dangerous — a floating iceberg can flip unexpectedly. I’ll post those photos another time, because I haven’t really had time to go through them yet, but I’m certain I’ll get some 3D files from them. Also got to see Mt. Erebus with no clouds and little wind, so you could see a puff of smoke rising above it.

Hexagonal ice crystals
Evan checks out some unusually large hexagonal ice crystals.

Then we went back to the ice cave, and this time, it was just me and him instead of a group of 15 people, and he brought a couple of good lights, which helped me get some better results. It also was a few hours earlier in the day, and it seemed to me there was more light coming through the small opening (very small — you have to crawl through it on your belly). I had learned from the first visit that the flash lit things too evenly. They were nice exposures, but you couldn’t see the depth. Even when I tried notching the flash down, it didn’t look so great. So, we experimented with having him point the lights he’d brought in different places to see what would work best for photography, and I discovered that indirect light worked the best — bouncing it off a wall, backlighting formations, or aiming it so the center of the beam was hidden behind a feature. Aiming the lights in that manner, we lit up some crystalline formations that I hadn’t even noticed the last time I was there, including some very large hexagonal crystals, an inch or more across! This is Evan’s first season here in Antarctica, but he leads winter mountaineering and backcountry ski camping trips in Idaho and Wyoming, and though he was familiar with hexagonal ice crystals he was astonished by the size of these.

Ice cave, hexagonal crystals
A closer look at the giant hexagonal crystals.

Ice cave entrance

Being inside the cave was literally being inside a walk-in freezer so I had to pause periodically to warm up my hands — my glove liners are usually pretty good for photographing but it was very cold in there after a while. Evan showed me some tricks that helped — swinging arms or pumping your hands up and down with your palms facing down. But after we’d been in there for a little over an hour, my fingers and toes had had enough, so it was time to go. But I left with some magical and strange images. They did remind me of some of the photographs I’ve made of cloud formations:

Ice cave

Ice cave


Ice cave

Ice cave
A change in the lighting makes this formation look different — see next photo.
Ice cave
A change in the lighting makes this formation look different — see previous photo.

Ice cave

Ice cave entrance
Approaching the entrance there’s a blue glow from the sunlight outside.
Sunlight illuminates the cave walls near the entrance
Leaving the ice cave