| November 11 |
Antarctica is the highest, driest, windiest, and coldest continent --- it can also be the most irritating. Due to weather and mechanical delays, I cooled my heels for seven days in Christchurch, New Zealand waiting for a flight to Antarctica. Though this may sound like a vacation, it isn't much of one in practice. One has to show up each day at the Antarctic Center terminal in order to don cold-weather gear, check-in, and catch a flight. The show-up times varied; sometimes 2:45am, sometimes 5:45am, even 8:45am. It all depends on the weather forecast the previous evening. You arrive, don the cold-weather clothes, check-in baggage, and then WAIT. Weather is checked and flights are put on two-hour, four-hour, even six-hour weather delay. There can be successive weather delays -- wait two hours, wait another two hours, and then they give up on the weather for the day. We even got on the plane one day, taxied around, and then there was a mechanical problem aborting the flight. You catch a shuttle back to town at 11am - 1pm or so. That blows off doing out-of-town vacation-type tours which all start first thing in the morning. However on two of the seven days, the flight was called off in the wee hours of the morning before I left for the airport and I was able to sightsee in the Christchurch area as well on a free day before my first scheduled departure day. I went whale-watching in Kaikoura to see sperm whales (also saw the little blue penguin, dusky dolphins, NZ fur seals, wandering albatross), went to see picturesque Akaroa (an historic French settlement on the Banks Peninsula), and went on a trip to Alexander Pass in the Southern Alps (including jetboating on a stretch of wild river and some back-country dirt road travel). Afternoons in Christchurch were spent reading or going to movies or walking around to kill time. Since my vacation leave clock was ticking, losing those seven days hurt.
On my eighth scheduled departure day, we boarded a C141 transport plane and departed for Antarctica. I squeezed in with 110 passengers, all in webbing seating running in two rows down the plane, with cargo in the back. You sit right next to others and have to intertwine your legs with the person facing you since there isn't much legroom.
Five hours later, we landed at McMurdo Station and the air temperature was a balmy 25 degrees F -- and it was sunny. The next day, I attended my required orientations: the waste management/recycling briefing; the truck/Spryte tracked snow vehicle briefing; and, the Snowcraft/Sea Ice/Helicopter Safety refresher briefing. Since I have been here before, I did a four-hour refresher on the last one rather than losing three days on them as do newcomers. The next day (yesterday), I did my required checkout scuba dive under the ice off Cape Armitage with the Scientific Diving Coordinator here. It was an outside dive, meaning we entered a dive hole out in the open that is bored in the six feet thick sea ice. The air temp was 20 deg F, the wind was blowing snow at 15-20 mph, wind chill was -5 to -20 deg F - things were frosty. I suited up, entered the water which is 28 deg F (at the freezing point of seawater), and immediately felt the seawater contact the only part of my body that was exposed: my lips surrounding my regulator mouthpiece. I had forgotten about that first frozen blast on the lips and today my lips are chapped like I have been kissing a freezer door.
The dive was great under the ice and I went down to 90 feet depth and looked around with a handlight. Since I have been working on a web-based field guide to the underwater animals here (at http://scilib.ucsd.edu/sio/nsf/fgui de), it was thrilling for me to see the animals now and know something about what I am seeing. On my previous trip, the creatures passing before my eyes were nameless and a fantastical, colorful blur, hard to pick out individual things in the passing parade. Now I know their names and it was like seeing old friends: hey, there's (scientific name); hey, there's (scientific name); etc. It all made much more sense what I was seeing and I poked along with the light, taking my time and inspecting the bottom life closely. The overall scene was familiar. I was diving on a black volcanic gravel slope with cliff drops of 10- 15 feet down in my 90 foot depth range. The sea ice ceiling up above looked like a relatively flat cloudy dark sky in shades of deep blue. Looking out horizontally, the water dimmed out to black. Looking up slope to shallower water, I could see broad fields of crystalline plates of anchor ice formed on the bottom. I was back and it felt good.
Finished the dive, made some minor gear adjustments, and reviewed some film footage shot by Norbert Wu, on whose National Science Foundation sponsored Artists and Writers project I am assisting. Norbert is shooting a high- definition film for PBS Nature here and I am gear carrying and helping out as before. The film footage I have seen is spectacular and I look forward to seeing it on in final form on television in Fall 2001.
This afternoon we are scheduled to go film Weddell seals at Turtle Rock, an offshore islet, frozen into the sea ice. Of course, I don't do the filming nor do I wish to attempt it. I am handling dive gear, doing still photography of the film work for promotional purposes, and other things. There are two $134K high definition video cameras in use each with underwater housings; it is all very high-tech looking and quite a different enterprise than the previous still photography shoots on which I have accompanied Norbert. In the days ahead, we will be camping at various locations in the McMurdo Sound/Ross Island area. If weather holds and things work out, we will be visiting Cape Roberts in order to dive/film at Granite Harbor (these are locations on the Antarctic mainland coastline - McMurdo Station is on Ross Island); New Harbor on the mainland coastline at the entrance to the Dry Valleys; and Cape Crozier on the NE corner of Ross Island -the location of the mid-winter journey by A Cherry-Garrad and others to get Emperor penguins eggs as chronicled in the book "The Worst Journey in the World." I am hoping for a better experience!
| November 12 |
Yesterday afternoon, we drove out to Turtle Rock, a small low rounded islet a short distance north along the Ross Island coast from McMurdo Station. Piling our gear into two Sprytes (two-track snow vehicles), we arrived and set up Norbert and Christian to go diving in a sea ice crack near the island in order to film Weddell seals underwater. I provided topside support and shot still photographs for Norbert of the general diving action plus shots of sponsored equipment in use. While they were underwater, I walked around and did some sightseeing. The air temp was in the low 20s and the wind was blowing at 15-20mph with gusts faster than that. Weddell seal mother and baby pairs were laying about in the open near sea ice cracks. The babies were snuggled close to their mothers, usually sleeping. I watched a baby and its mother nuzzle each other and the baby Weddell seal made its characteristic howling/moaning call. I watched a baby nurse on mother's milk as well. Though it was windy and cold, the seals were so well insulated that they were laying about like it was a sunny day at the beach. The air was clear and I could see the long stretch of the Antarctic mainland coastline with the Royal Society Mountain range and its glaciers stretching away at least 80 miles or more.
The next day (today) we went to Turtle Rock again. This time I went diving with Norbert. I suited up at the vehicles and then did a long walk to a sea ice crack to get into my dive gear and get in the water. McMurdo staff workers go along to help us on their day off; they haul the dive and camera gear around for us so that really helps. Again the air temp as in the low 20s but the wind was much less. My drysuit undergarments kept me sufficiently warm out in the open before I suited up; the drysuit only keeps me dry and its undergarments keep me warm in the 28 degree F water. My undergarments are in three layers: expedition weight long underwear; a WarmWind polypropylene jumpsuit, and a thick DUI thinsulate jumpsuit with a nylon windshell. They actually are too warm to wear about in 20 degree F weather and I have to open up the zippers a bit to cool off; it isn't good to start a cold water dive sweaty which then speeds up the chilling process. The sea ice crack was a jagged crack about five feet long and about 2 1/2 feet wide at two points. You sit at the edge, get helped into your dive gear, and then ease yourself into the sea ice crack, with the seawater about 2 1/2 feet down from the surface of the sea ice. You twist and turn a bit and scrape around to get yourself and the scuba tank on your back into the water properly at the crack's widest point. Then you stick your regulator in your mouth and start descending further down the crack until the crack ends and you are under the sea ice ceiling. It is very close quarters; you push down with your hands on the walls of the sea ice crack in order to go down and you twist and turn a bit to squeeze through. If you are claustrophobic, then this isn't the dive for you.
So I started down, took an inhalation, and my regulator let in air mixed with a large volume of icy slushy seawater. I blew it out, took another breath that was again a large volume of icy slush with air. Took a few more and decided I wasn't going to get a proper air supply and didn't want to spend my dive trying to breath and spitting out seawater ice slush with every breath. I surfaced, pulled my regulator out of my mouth, and a team member (DJ) reached down into the sea ice crack, pulled open my regulator assembly, and cleared out an ice bit stuck in the regulator diaphragm (which was creating the leakage). I put the regulator back in my mouth and reached up for my hand-carried items. I was tasked to bring down an Antarctic cod fish head to place on the bottom in order to film invertebrates climbing and feeding on it. I had not seen it previously and was simply told I was to take down a fish head and place it on the bottom. I looked up from the surface of the seawater as I was wedged in this sea ice crack and a monstrous fish head about 2 1/2 feet long and 18 inches in diameter was handed down on top of me. I laughed internally as this huge fish head blocked out the sky and became my special friend (let's call him George), wallowing on top of me as I grappled to find a gill slit in order to grasp George with a free hand. I did so and then reached up for my other hand-carry item: an octopus in a mesh bag that I was to let loose with Weddell seals nearby in order to film their curiousity. Another special friend along for the ride.
I descended vertically down the sea ice crack and then it opened out -- I was under the six foot thick sea ice ceiling with the bottom at 12 foot depth. We were on a shallow bench nearshore Turtle Rock and the bottom was covered with black volcanic gravel. Ice was forming on the bottom in crystalline plates (called anchor ice) and was spread out in broad crystalline fields here and there. The sea ice ceiling was covered with these crystalline plates as well; it was wavy and mounded and hitting bottom here and there. The overall effect was diving in an underwater ice cave with a very low ceiling. Some areas I went through gave me a few inches clearance below and above me. Some brine stalactites were seen here and there; supercooled brine drips down from the sea ice ceiling and freezes the surrounding seawater into a hollow tube of clear ice extending to the bottom. In some places, larger clumps of anchor ice had broken free of the bottom and were slowly floating up to be incorporated into the sea ice ceiling. Gravel could be seen embedded in the crystalline sea ice ceiling that had been entrained in anchor ice floating up. Here and there, one could see bright areas of sunlight shining on the shallow bottom; these were under sea ice cracks and holes used by the Weddell seals to get in and out of the water. Weddell seals could be seen cruising slowly and gracefully here and there and I could hear their underwater vocalizations.
The gravel seafloor was largely barren since it gets swept clean by the ice forming on the bottom. The only animals were mobile ones since stationary animals would be engulfed by anchor ice. There were small seastars in profusion; some long bicycle-inner-tube-like nemertean worms about four to five feet long; giant isopods looking like armored bugs as big as my hand; sea spiders; small sea urchins; a few large seastars; a spiny worm; ---- and lots of Weddell seal poop, which was supporting most of this ecosystem. The animals were piled up eating the seal poop. Enough of that. I placed George down and bid him farewell. I swam over to Norbert and let the octopus out of the bag near some Weddell seals; they couldn't have cared less. After awhile I herded the octopus back into the mesh bag and then started picking up small seastars and putting them into the mesh bag. They are now in a large aquarium tank at McMurdo where Norbert will time-elapse film them attacking and eating the large seastars on which they prey. I was then on my own and explored this icy underwater palace. Weddell seals passed me occasionally or I swam through their breathing hole territory. A large male seal passed by, making an assertive or territorial sound, that sounded like a very deep doonk, doonk, doonk --- I felt like I was being sonar pinged and I could feel the deep loud sound throughout my body. The seal didn't come after me and the next time I saw him, I imitated his sound and he turned his head and stared at me -- probably laughing at this pathetic assertion of Weddell seal masculinity. I terminated the dive after sixty minutes underwater and I did not suffer from the extreme cold hand syndrome as I did two years previously. I have found better gloves and though I wouldn't say my hands were warm, they definitely were not getting stiff and cold and screaming at me.
I looked closely at George before I ascended up the narrow sea ice crack. George was covered with reddish amphipods dining happily, one seastar had already starting climbing aboard to chow down, and several small fish were nipping at pieces of George. The feast was beginning. The octopus and I ascended, I twisted and turned a bit to get my head out of the water, handed up the octopus bag, then wiggled here and there while I unfastened my scuba tank harness and my weight harness and handed them up. I then hoisted myself up and out of the sea ice crack in a most ungraceful manner and felt a happy glow from experiencing a wonderful dive under the ice with the Weddell seals.
| November 15 |
Here's an update of today and the previous two days. Two days ago in the morning, Dale and I went with Kevin and Terri of Art Devries research group to help them pull in Antarctic cod, Dissostichus mawsoni. They catch them with a baited line of ten hooks set to a depth of 1,568 feet from a hut set up over a hole bored in the sea ice about two or three miles offshore McMurdo Station alongside the sea ice road to the airplane runway. The Antarctic cod is a deepwater fish and can be huge; they used a steel cable fish line and huge hooks with 6-8 inch long fish as bait. They winched up the line and pulled six Antarctic cod off the ten hooks; the largest was 5.6 feet long and 118 pounds. This is the same species of fish as the fish head (George) that I took underwater at Turtle Rock previously. I helped Kevin haul the big one up from the sea ice hole; we reached down with our bare hands and grabbed it up under its jaws in front of its gills. It was truly an awesome fish with pretty big teeth and a huge mouth; it struggled, I struggled, we struggled and we hauled it up and flopped it on a weighing/measuring tray, after which we lifted it into a fish transport coffin with aerated seawater. Other fish were also hauled up, weighed, measured and put into fish transport coffins; the smallest about 35 pounds. They selected the fish to take back for research on their antifreeze proteins and physiology and released the largest one and some others.
That afternoon I did a dive on the sloping wall at Cape Armitage to a depth of 130 feet for 36 minutes duration. There was a very stiff wind blowing snow almost horizontally and air temp was low; we suited up in a tent-like hut and then stepped outside to walk a few steps to the dive hole and get in the water. I was tasked to stay in Norbert's general area underwater and spot anything interesting happening and wave him over to film this. We were diving a study sight named Dayton's Wall after Paul Dayton of SIO who did a lot of the defining benthic ecological work here. There was a submerged buoy anchored downslope that marked some of his study area. I enjoyed seeing the large volcano sponges and myriad other sponges, vertical wall sections of 10-15 feet height, the colorful soft corals, and lots of invertebrates. Weddell seals could be heard vocalizing in the distance underwater but I only saw one. I didn't see anything interesting in animal behavior to wave at Norbert for filming. Invertebrates move very, very slowly in Antarctica and much of what a diver sees looks great in still photos and would simply look like static scenery in a film. Films need action so Dale has now setup an aquarium tank with a natural volcanic gravel bottom in order for Norbert to do time elapsed filming; Norbert started with seastars gang-attacking a larger seastar. A lot happens underwater in Antarctica but it is on seastar time and not human time.
The next two days (Nov 14-15) we did dives at Turtle Rock with the Weddell seals. On each day I did a single dive of 63 minutes duration with most of my time spent in the shallow water exploring the seafloor life, ice caverns, and Weddell seal breathing and haulout holes as I described previously. With now three hours time spent underwater over three dives at Turtle Rock, I have it burned into my memory circuits fairly well and it is an unforgettable diving experience. My now-heavier weight belt was perfect and my diving was carefree. One has to be weighted with a lot of weight to counteract the thick undergarments and to allow air inside the drysuit for insulation in the undergarments. I tend to be buoyant and my weight belt is 48 pounds (others are at 40 plus pounds) and I use ankle weights for an additional 4 pounds. In combination with a steel 95 cubic foot scuba tank, I am heavily encumbered out of water and especially as I crouch down to get into a dive hole. Underwater I am weightless. My under-gloves are doing a good job keeping my hands from getting too cold and my limiting factor underwater seems now to be air consumption or having to take a leak. It would be interesting to see how long I can take this immersion in 28 degree water; I'm not warm throughout but I'm not freezing cold either --- more an uncomfortable state in between that I know will pass. Actually the worst situation is my lips, just like everyone else getting started diving here. After exposure to cold, dry winds and exposure to 28 degree seawater, one's lips freak out, crack all over, and start sloughing shreds and sheets of skin. I hope it ends soon because my lips really sting from the seawater when I start a dive until the freezing water takes over as an anesthetic.
There was a Weddell seal pup carcass on the bottom nearshore; it was covered with amphipods and seastars devouring it. There were numerous amphipods on the bottom surrounding the carcass that had evidently engorged themselves and were killing time digesting. I stirred them and they didn't react. George, the fish head, had been carried fifty yards closer to shore by a seal, and was being eaten by a giant Antarctic isopod, amphipods, and seastars. Weddell seals cruised by here and there in the ice tunnels, low-celing passageways, and rooms. A baby Weddell seal with its mother following approached me underwater in a ice room. The baby seal swam slowly right up to the top of my face mask as I held still so as not to spook it. It nosed around on my neoprene-hooded forehead and I realized that it was playing with its nose in the air bubbles that stream up from the regulator in my mouth. The baby seal continuing nosing at my forehead and my bubbles as it probably enjoyed the sensation on its whiskers. I looked down and over and saw its nine foot long mother watching me VERY closely from about seven feet away. The mother's vigilance made me decide not to engage in any reciprocal behavior with the seal pup. After the pup nosed around awhile, it swam fluidly away and mother followed.
I moved throughout the area, keeping a careful eye out at all times for the route back to the ice crack from which we entered the water (which I described previously). Weddell seal underwater vocalizations can be heard occasionally throughout the dives. Turtle Rock is a tricky area with lots of under-ice passages and ice rooms and it is easy to get lost wandering around. Nearshore the sea ice is jumbled into pressure ridges reaching down to the bottom in large rounded boulder-like forms, constructing rooms, some with beams of light shining down like spotlights from holes in the ice above. Ice tunnels connect the rooms and parallel tunnels have low-ceiling caverns which you can pass through to move from one tunnel to another. Clearance can be tight in some spots; one time, I measured about 18 inches from my chest to the seafloor when I floated my back up right against the ceiling. Other areas it was like caving, where you move through a crack between ice boulders to move from one ice room to the next. The advantage is that you float through weightless and don't have to crawl and get dirty.
Tomorrow Norbert and I fly by helicopter to Cape Roberts on the Antarctic mainland, which will be our base of operations to snowmobile to dive sites around the Granite Harbor area, including Couloir Cliffs. We will be sleeping outside on the sea ice in tents but using the bathroom and kitchen facitilities of the Cape Roberts drilling encampment. We are joining up with Christian and Dale, the other members of Norbert's film team, who left the day before to set up our tents and start scouting dive sites and ice cracks in the Granite Harbor area. This field trip is scheduled for up to ten days so I will be out of contact for awhile!
| November 20 |
I spent the last four nights/five days at Granite Harbor. Norbert's photography objectives were accomplished relatively quickly given the lack of open sea ice cracks there; he didn't need as much time as anticipated. Since it is logistically involved for NSF to set us up in our own field camp, we share the field camps of other scientific parties when we go off-base for overnighters. For Granite Harbor, we stayed at the Cape Roberts seafloor drilling project/encampment which supports forty people at a location on the sea ice at the south end of Granite Harbor. Granite Harbor is a very large bay on the Antarctic coastline about eighty miles from McMurdo Station on Ross Island. Granite Harbor is distinguished in its middle by the large Mackay Glacier spilling down a broad valley and into the frozen ocean, extending out into the water in an glacier ice tongue. The Mackay Glacier is a river of ice flowing downhill towards the coast from the Antarctic interior. Cape Roberts is a collection of mostly interconnected insulated cargo containers holding kitchen, shower room, laundry, electrical generator, desalinator, bunk rooms, science lab, and dining space. There was no sleeping room for us so we pitched tents outside but ate in their meal shifts and used their showers. The cooking was great so that was nice after a long, cold day.
The frozen sea ice around the Cape Roberts encampment is embedded with large icebergs that drifted in, ran aground, and then froze in place by the seasonal sea ice. It is a spectacular setting with large blue-ice icebergs, many with flat-tops, which indicate that they have broken off from permanent ice shelves like the Ross Ice Shelf many miles away. Some frozen-in ice bergs were irregularly shaped on top which indicates that they had calved off from seaside glaciers or were tipped-over icebergs. Looking back towards Ross Island eighty miles away, we could see its towering Mount Erebus, the world's southern-most active volcano.
Every morning we loaded up scuba diving gear and scuba tanks on Nansen sledges that we attached behind SkiDoo snowmobiles. The five of us (including Rob Robbins, the Scientific Diving Coordinator at McMurdo) would go on three SkiDoos and drive about 4-5 miles on the frozen sea ice along the coastline towards the middle area of Granite Harbor -- the objectives being two stretches of seaside rocky cliff called Couloir Cliffs and Discovery Bluff. The coastline along which we snowmobiled was mostly glacier cliffs and also some snow covered rocky cliffs and points. Weather was typically 20 degrees F plus or minus with winds making for a colder wind chill. The drive along the sea ice crossed patches of sea ice blown free of snow which is like driving on slick blue ice. Other sea ice sections had snow cover, either evenly distributed or accumulated in small hard ridged drifts (sastrugi). The snowy sastrugi patches were sometimes sparsely distributed on the blue sea ice, making snowy white arabesque patterns on the blue sea ice. The sastrugi also made for slower, bouncy snowmobiling.
As I mentioned, several of the team had arrived the previous day and had chain sawed open a dive hole at Couloir Cliffs. There were almost no open sea ice cracks for diving entry along this stretch of Granite Harbor coastline which was why a chainsaw hole was necessary for entry to Couloir Cliffs underwater. The visibility underwater on all my dives has been great by any standard. The dive coordinator here at McMurdo estimates that the average underwater visibility is 300 to 600 feet; another expert measured a maximum at 800-1000 feet. I did several dives at Couloir Cliffs, a long rocky cliff along the coast. The underside of the six foot thick sea ice was covered with brownish algae and diatom growth, almost like a mat. The sea ice cracks were jammed shut and tented up into vaulted ceilings lit brightly with the sunlight shining down through the thinner crack ice. One dive to 109 feet involved repeated swim-overs of large volcano and other rosselid sponges as Norbert filmed me. The seafloor was cobbled and boulder strewn on a steep slope covered with colorful sponges.
On this dive late at "night", the sun angle was low and it was very dark underwater, like a night dive. The air temperature topside was in the upper teens and the breeze blowing made the wind chill -5 to -15 degrees F. It was very cold changing from topside clothing into the dive gear. To make it easier, I wear my drysuit undergarments all the time so I need only put on extra insulating footwear, don my drysuit, and then put on head and hand gear along with the rest of my dive gear. HOWEVER, this process exposes one's bare head -- and particularly hands -- for some period of time and that is where it can get brutal when the cold Antarctic wind is blowing. My drysuit undergarments consist of expedition weight long underwear, a WarmWind polypropylene jumpsuit, and a DUI 400G thinsulate jumpsuit with nylon wind shell; all of them combined are warmer than standard issue US Antarctic Program Extreme Cold Weather Clothing. I wore them snowmobiling and while standing around outside tending the dives of other members of the team.
Back to that cold "night" dive -- my dive gear from my previous dive remained wet and I had left it inside my dive bag which stayed out in the open at the dive site. When I pull out my neoprene dive hoods, they were frozen stiff from the seawater left on them so I worked them onto my bare head as my head warmth loosened them up. Putting on the drysuit is easy because it is a trilaminate material which doesn't retain surface water -- and thus doesn't freeze up and stiffen -- except for the feet boots which were frozen and stiff and had to be worked carefully onto my feet. One uses bare hands to finish donning, buckling, and hooking up dive gear because it can be wet work and dexterity is needed. Move fast, slip your hands into your drysuit insulating gloves, and then the cold wind doesn't matter. After the dive, it was so cold that the seawater on my drysuit froze into a frosty crystal sheen as I exited the water, then my outer hood and drygloves froze into a crystal sheen as well. With the wind blowing, it was disconcerting taking my gloves and hoods off and exposing my head and hands after a long dive in such cold water. I moved quickly and got into my regular topside hand and head wear.
One dive at Couloir Cliffs lasted 74 minutes -- my record time underwater. As I swam underwater towards the shallow shoreline under the ice, a Trematomus bernachii fish that was eight inches long rose up and faced off in front of my dive mask. Charmed by this unusual encounter, I held my ground as it approached the top of my dive mask and inspected me closely. I was recalling my recent face-to-face encounter with the curious Weddell seal pup as this fish darted in and took a bite of my upper lip with its thin covering of neoprene ice hood. This was the final Antarctic insult for my chapped, cracked, and shredded lips; I shrieked in pain and waved the fish off. My lips are the only part of my body exposed to the water and I guess a whitish lip under a thin neoprene ice hood looks like a wound to nip at on a Weddell seal or something. It really hurt since the fish had serrated jaws but it didn't get a chunk out of me since the neoprene ice hood deflected its bite. The cold water dulled the pain and I moved on.
I saw a jellyfish with tentacles about twelve feet long and with hitchhiking amphipods on its clear gelatinous bell. The bottom in shallow was strewn with boulders of all sizes and was covered copiously with crystalline jagged anchor ice. I swam along the underwater base of the steep cliffs, covered with frozen meltwater which had run down from the topside portion of the rocky cliffs. The meltwater formed a smooth wall of frozen crystalline ice along the underwater rocky cliff, with crystalline anchor ice carpeting the wall in some areas and with other wall areas left barren. Sea urchins and some seastars crawled up on this ice wall, grazing on algae. Some moved too slowly and ice had overgrown them; they were embedded under ice and would be a nice meal for an urchin or seastar later when the ice thawed. The sea ice ceiling had numerous hollow brine ice stalactites handing down. I entered one tiny cove along the cliff shoreline that was a stalactite room filled with numerous stalactites hanging down from the ceiling with many almost touching the shallow (9-10 foot) bottom. I swam among them to the back of the room, which was lit a brilliant deep blue by the sunlight filtering down through the sea ice along the shoreline. The floor of the stalactite room was carpeted by crystalline anchor ice -- it was quite spectacular. There were two tiny coves that were blue rooms with crystalline floors, deep blue back walls, and deep blue ceilings; it was like swimming into a 60s black light room (but no psychedelic posters). There was a frozen-up ice crack along the shoreline that let in streams of brighter light in some sections along this frozen stretch of cliff shoreline. A large Weddell seal cruised by on a long traverse under the ice; it looked quite surprised to see me underwater and I was very surprised to see it since there were no seals in the immediate area and no holes other than our chain sawed hole. The boulder- strewn shoreline allowed for a succession of rooms along some stretches of the shore; one could pass through bouldered tunnels between adjoining icy rooms. Norb did swim-over filming of me poking around when we crossed paths a few times on this dive. One time he gauged his swim-over too closely and ran the bottom of the movie camera housing into my head! We repositioned ourselves for another take.
One evening, Dale and I took a snowmobile drive around the grounded icebergs surrounding Cape Roberts. We drove through flat valleys surrounded by flat-topped, towering blue iceberg mesas. Icebergs were blocked or sculpted, had fallen blocks sloughed off, had blue frozen meltwater pools at their base, had stratified snowcaps showing years of minuscule snowfall in layers like sedimentary rock, or were cleft with large cracks that were deep blue inside. One spectacular iceberg had a long horizontal crack at ground level with a sky-blue background with overhanging tall icicles at the edge and a blue frozen meltwater pool at its base. The late night low angle sunlight accentuated the blue ice color of these grounded icebergs.
Another day, we scouted for a Weddell seal entry/exit hole along sea ice cracks at Discovery Bluff in order to have a place to enter the water for diving. At Discovery Bluff, there were mother and baby Weddell seals laying out along a sea ice crack with a few holes and also some male seals. Discovery Bluff is a steep rocky huge hump of a hill and underwater it is the same -- large rocks and boulders on a steep slope as one moves away from shore. My dive at Discovery Bluff was on a nice, sunny calm day with air temperature in the upper twenties -- shirt sleeve weather. There was a nice sea ice crack in a tented-up pressure ridge along the shoreline with a large seal hole for us to enter the water. Seals would pop up their heads occasionally and take several breaths right next to us as we set up dive gear and finishing suiting ourselves up for diving. They didn't seem to mind our presence at or use of their hole. Underwater, the sea ice crack displays its tented-up topside appearance by having a somewhat vaulted ceiling along the crack, with the light shining through the thinner ice of the crack next to the six foot thick, regular and largely flat, and much darker blue sea ice ceiling. Right under the seal hole where the sunlight beamed down on the very shallow bottom, leafy algae was growing. There has been much sunny weather this season and the underside of the sea ice was pretty brown from algal and diatom growth this early in the season. Just inshore of the sea ice crack, there was a blue ice wall along the shore and one could follow along to a very shallow and small cove, entering a blue-walled crystalline ice room with crystalline anchor carpeting the floor and crystalline platelet ice covering the ceiling. The deep blue coloration one sees from light filtering down through the sea ice is remarkable and serene. I spotted a small jellyfish floating nearby in this glittering deep blue room and inspected it closely; it was covered on its clear gelatinous bell with hitchhiking amphipods -- small crustaceans getting a free ride for a chance at running across more food to catch. I then went down the boulder-strewn slope to 119 foot depth and passed white lacy nudibranch sea slugs; lacy white bryozoans; long sea whips; large clumps of soft coral in profusion in shades of pink and orange; numerous seastars in reds, yellows and white; reddish sea urchins; and, yellowish sea spiders, including one larger than the span of my hand. Down deep, there were big white volcano sponges and yellow cactus sponges.
| November 23 |
Yesterday I did a collecting dive off Cape Armitage at 90 feet for half an hour. I described this area previously. It is a relatively steep slope covered with the variety of Antarctic benthic life (sponges, sea spiders, soft coral, anemones, worms). The sea ice overhead looks very blue-dark and cloudy, like a stormy sky. It is very dark underwater and the color on the animals only shows up with a light -- otherwise everything looks blue-gray in color. A large Weddell seal swam slowly by way up overhead as I poked around on the slope. Christian was tasked to collect helmet jellyfish and I was to collect some anemones. I selected various Isotealia anemones that were attached to small rocks semi-buried in the muck on the slope; this muck is very soft being the accumulation of sponge spicules and other matter into a mat over a foot thick. I also found a helmet jelly on the bottom as did Christian who found two; they come in on the currents from the open ocean and bump into the bottom along the coastline here. We brought them back up in buckets for transport to a setup tank in the lab aquarium for time-lapse filming.
Today I did a dive for a half hour at Little Razorback Island to scout out Weddell seal filming for Norbert while he went diving at another site. A dive hut had been dragged out and placed over a hole bored through the six foot thick ice ceiling. The hut is heated so this is a much more comfortable and civilized way to dive, without exposure to the wind and cold while suiting up or unsuiting. The Little Razorback Island site is much like Turtle Rock (previously described) but it has a less extensive shallow bench underwater (ten feet deep), and less underwater ice pressure ridge tunnels and caverns. The bottom is covered with patches of glittery jagged plate-like anchor ice. I moved in close to the island's shore which is ringed with ice pressure ridges with seals laying about on top of the ice. The seals use holes and cracks in these shoreline ice pressure ridges to get in and out of the water. Right next to shore, my depth was only three feet as I moved along a shoreline pressure ridge tunnel system that corresponded to the seal haulout holes. I approached a large Weddell seal in a shallow ice cavern who was breathing in a hole on top. He came underwater and towards me, doing the male territorial sound, a deep chooonk-choonk-choonk (hard to describe). I watched him move off and continued on.
I spotted a dead fish covered with seastars and amphipods -- quite a feast for them compared to the usual seal feces, also widely prevalent as I swam around. I moved back offshore through a narrow ceiling section which was one of the few ways out. When I lifted my body and scuba tank up against the ice ceiling, my bottom clearance was the length of my forearm from elbow to wrist. Split that length in two and that is how much clearance I have on top and on bottom as I move under the sea ice ceiling towards shore and away from shore -- in the areas where I can do so and where the ice ceiling is not almost touching the bottom. After exiting the island's shallow shoreline bench, the bottom drops off incredibly steeply down a talus-like slope into inky depths. In this short distance away from shore, the sea ice ceiling is undisturbed by pressure ridges and appears as a flat blue-colored ceiling. I swam a long way around the island; I then turned back when I felt my air volume indicated that I had better head back for my way out. Throughout this swim along the edge of the bench, I would see possibly that same male seal; I think he was cruising about through the area and I wouldn't be surprised if he was keeping tabs on me. It took me quite awhile to swim back but I managed my dive correctly and had ample air left. I poked around a bit more and surfaced in the dive hut's hole. After the dive, a baby Weddell Seal surfaced to take breaths in our dive hole inside the dive hut. He looked at us curiously between breaths as did we at him!
| November 24 |
A long day today -- we drove in a convoy of two Sprytes an hour and a half up the Ross Island coastline along the frozen sea ice to Cape Barne in order to dive on a grounded iceberg. I drove one of the Sprytes myself so, rather than napping, I saw the McMurdo Sound/Ross Island scenery at a pace of about twelve miles an hour. It was a sunny clear day and I could see across the frozen ice of McMurdo Sound to the Trans-Antarctic Mountain range along the Antarctic coastline about fifty miles and more distant. As we drove along a marked route on the frozen sea ice that roughly paralleled the Ross Island coastline, we passed by Turtle Rock, the Erebus Glacier Tongue (a blue ice glacier that extends far out into the ocean like a peninsula -- but now frozen in by sea ice of course due to the season), a group of small islands including Little Razorback, Cape Evans with Scott's ill-fated Antarctic expedition hut visible, Barne Glacier (vertically cleft blue ice glacier cliffs along the frozen shore), and then approached a iceberg that had floated in, grounded itself on a pinnacle, and become frozen in by the annual sea ice.
Topside, the iceberg was composed of several sizes of blocks, with the smaller blocks having calved off the largest block. The iceberg was surrounded at its base by a crumpled sea ice pressure ridge with a few Weddell seals and a crabeater seal laying out nearby. We used one of their holes to enter and exit the water and they paid us no heed. I did two dives totalling a bit over an hour underwater. As I descended, I wiggled down around some ice boulders immediately under the hole and then it opened out into the passageway under the crumpled sea ice pressure ridge alongside the iceberg. Dropping down a bit further, I was under the sea ice and on the wall of the iceberg itself as it dropped down toward deeper water below. The iceberg wall itself was whitish- blue and covered with big dimples like a golf ball. Small silver fish were flitting about on it. There was a fairly strong current coming in from the direction of the open ocean miles away; I hung onto the downline as I descended so I wouldn't be swept away and have to kick my way back hard to the hole.
The iceberg wall sloped down at a sixty degree angle and then steepened to a vertical drop down to the bottom at 85 feet or so. The bottom was actually the top of an undersea pinnacle on which the iceberg had grounded itself. The pinnacle was covered with a lush lawn of large orange-pinkish soft coral, looking like chubby bushes. The iceberg stretched as far as I could see in both directions and was actually undercut on its very bottom; it looked like a huge blue ice ship or submarine run aground. I swam towards the up-current edge of the pinnacle; I looked down a steep slope into blue-blackness and then I looked to the right and under the iceberg; the pinnacle also sloped down steeply there into blue-blackness. Neither was an inviting direction in which to venture so I turned back towards the middle of the pinnacle. In the passing current, clear gelatinous comb jellies (including lots of Beroe) were streaming by and I also saw a very large jellyfish with long, long tentacles go by. The strength of the current made every diver cautious and respectful. Though I dive in ocean currents as strong as this off Point Loma, I don't have the option to swim back on the surface to the boat here in Antarctica. When that one dive hole is the only way out and the current is running, one stays pretty close to the downline to avoid having to swim hard back to it and using up lots of air in the process.
The pinnacle top not covered by the grounded iceberg was relatively small in area. After ranging around a bit, I spent considerable time just sitting back on the bottom, weighted down and just looking around and up. Down deep where I was lounging on the bottom, the iceberg looked just like a huge blue ice ship grounded on a underwater peak. It was an impressive scene and I could see each direction at least two hundred feet. Away from the iceberg, the underside of the sea ice ceiling was flat and covered with dark brown algae. In places the algal mat had holes; sunlight came through these holes so the sea ice ceiling looked like a dark brown nighttime sky with twinkling stars of light. Since it was sunny outside, sunlight streamed down from the seal hole at a 45 degree angle and shone like a spotlight on the iceberg wall. The sea ice crack around the base of the iceberg also let in sunlight on its irregular path around the iceberg. The play of light underwater here is truly remarkable; it streams down through cracks and holes and provides strong contrast to the general bluish dark twilight underwater.
| November 25 |
Today we returned to the grounded iceberg off Cape Barne that I described yesterday. It presents such an incredible underwater scene that Norbert is filming it in every possible way, including the usage of high-intensity underwater lights powered by a surface generator and connected by a long underwater cable. I slipped down the seal hole for a fun half-hour dive between Norbert's filming dives. I won't describe the grounded iceberg again (see yesterday) and I will stick to what was different for me this time down for a half-hour dive. First off, I entered the water at slack tide or something; the current was almost nothing so I felt comfortable roaming far away from the hole --- and so I did. I went up current to the very front edge of the iceberg which was a long, long swim from the hole and way, way out of sight. I swam forward at about the 20-25 foot depth level along the upper flank of the berg.
The golfball-like indentations on the iceberg flanks are occupied by small silver fish either individually or in pairs. The indentations are actually quite elaborately sculpted by the micro-eddies that must swirl from the passing water. What looks like a simple concave indentation from far away has, on closer inspection, little back caves or carved ledges in almost every indentation. The silver fish occupy these little caves or ledges, oftentimes curled up in them due to lack of space. Little bits of algae and detritus are caught in these tiny caves and ledges so it looks like the fish have a nest. It seemed that this was an ideal habitat to hang out and then dart out to eat something interesting passing by in the current of water sweeping along the iceberg. I looked hard but didn't see any eggs with the fish so they may not be nesting.
I continued on up the grounded iceberg wall and then the top part of the wall stretched back and flattened out to my right. A large male Weddell seal approached me head-on and did the characteristic underwater territorial sound - a deep choonk, chooonk, choonk sound. I held my ground and did not advance towards him; he swam to the back of this flattened berg top under the sea ice which was like a large room with a seal hole at its top. I had obviously entered HIS space in the vicinity of HIS hole and he was letting me know. After I determined that he was just going to watch me and not come after me, I continued swimming on to the front end of the iceberg. The pinnacle top sixty feet below me dropped away beneath the front of the iceberg and I couldn't see a bottom. The iceberg was run aground on a pinnacle tip pressed against its middle it seemed and I was on the forward portion cantilevered out over some deep water. I finally came to the front of the iceberg and turned a corner; the iceberg was flat-fronted and very broad. I had come far enough and safety dictated that I turn back with my remaining air. On the way back, I saw that Weddell seal some more, swimming around in the open water off the iceberg and zooming along the iceberg wall. . He was about nine feet long and a huge blimp of a seal --- very well insulated and a master of this environment. Not me. Stuffed into a drysuit with voluminous undergarments and wearing a mega-weight belt, double neoprene hoods sandwiching a latex hood, and loads of dive gear, I am a noisy, bubbling, encumbered beast that probably invokes more pity from these seals than concern as I enter their territorial space. I dropped down to the pinnacle top and renewed my memories of this grand scene of the iceberg run aground. It was time to ascend.
As I neared the hole in which to exit the water, that Weddell seal was there in the tunnelled chamber under the sea ice pressure ridge at the hole. Since he was there first and it is not good practice to jockey for an air hole with a huge air-breathing mammal with teeth, I held back and waited. A second Weddell seal approached the area under the hole at a depth of 15 feet. The first Weddell seal turned towards that seal, swam quickly to it, bared its teeth, and attacked -- a duel for the hole was on. Both seals were showing teeth and biting each other, tumbling and swirling around each other, like an underwater catfight mixed with synchronized swimming. The seals are so fluid in the water that even their fights look graceful. They ignored me as I watched from fiftteen feet away and held my ground. I wasn't going to contest that hole since I was watching what might happen to me if I made a move towards the hole to exit. The seals tussled for 15 - 20 seconds and then one seal turned and swam off with the other chasing it off for about twenty feet. The victorious seal then turned and went to the hole and took several long slow breaths as I watched and waited for my turn at the hole. I had enough air and was prepared to wait a long, long time after what I had just witnessed. The seal then submerged and swam off, leaving me to make a very hasty exit up that hole and out of the water, should that seal return and see my rear end and flippers hanging down from the hole. I look more seal-like from that perspective.
| November 26 |
McMurdo Station doesn't celebrate Thanksgiving until Saturday (today's Friday) but it does take off a two day weekend for holidays instead of the usual one day weekend (a six day work week here). That doesn't stop us though and we can dive locally while McMurdo is shut down for the holiday weekend. Today we helicoptered out to the sea ice edge of McMurdo Sound in order to film penguins swimming and diving in the water. McMurdo Sound is the body of water between Ross Island (on whose southern tip sits McMurdo Station) and the Antarctic mainland. McMurdo Sound itself is a small section of the much larger Ross Sea, an embayment on the Antarctic continent that is larger than France in area. Ross Sea has a permanent ice shelf and extending from that seasonally is annual fast ice. So we helicoptered out to the edge of that annual fast ice (by February the annual ice will have broken out all the way back to McMurdo Station). Right now the ice edge of McMurdo Sound extends from the northern part of Ross Island under Mount Bird across McMurdo Sound to the Antarctic mainland somewhere way north of Cape Roberts/Granite Harbor, where we camped. When we were standing on the sea ice edge today, we could see way, way up the Antarctic coastline beyond Granite Harbor, which was about seventy miles away from where we stood. I would guess I was seeing coastline one hundred miles away - it was that clear and sunny a day.
The helicopter pilot and Norbert scouted locations along the sea ice edge suitable for Norbert's film objectives. Looking down, I could see the larger Emperor penguins and the smaller Adelie penguins. It was windy when the helicopter landed us at the ice edge so we stayed bundled up. After we landed and started unloading gear, some Emperor penguins walked or tobogganed over to the helicopter for a closer look at us. Emperor penguins make a characteristic honking greeting even to non-penguins like us so we felt welcomed. Emperor penguins are the largest penguin, about three feet tall, and are very stately and calm - truly magnificent birds. They are curious and followed us as we hauled our gear from the helicopter to the sea ice edge. More Emperor penguins arrived as minutes ticked by; they were coming from near and far to observe our activities. There is nothing out here but flat sea ice and ocean for miles in every direction, so I imagined that we constituted considerable amusement on a slow day. The smaller Adelie penguins also came over to hang out with the Emperor penguins and us. At the largest, our encampment numbered three humans, twenty plus Emperor penguins, and about fifteen Adelie penguins.
As we hauled our first load of gear to the sea ice edge, a minke whale surfaced as it passed slowly by our area. Minke whales are plankton feeders and that was the only whale, minke or killer, we were to see today. Norbert got into his drysuit and I helped him into his dive gear and into the water so that he could film underwater. Dale and I brought our drysuits, masks, fins, gloves, etc. so that we could snorkel and see the penguins swimming underwater. Dale went first and then I.
Since the wind was blowing so stiffly, it was very cold exposing hands and head to that wind while donning my drysuit and gear. My drysuit's CF compressed neoprene booties were frozen and difficult to slip over my feet; the rest of my drysuit is a different material which doesn't retain moisture (trilaminate) and therefore much easier to don in frigid conditions. The funniest thing was seeing Dale wiggle out of his drysuit after he had been out of the water for some time; his suit is entirely made of the same CF compressed neoprene material as my drysuit booties and Dale was encased in a frozen stiffened drysuit and had a devil of a time getting the thing off.
At the sea ice edge, I went through the motions of putting on my fins, mask, etc. Divers typically spit on their mask's faceplate to put a viscous layer on it that keeps the faceplate from fogging up during the dive. As usual, I did so and my spit froze quickly inside my mask - it was that chilly out there. I slipped into the water and floating out along a drift line to take a look.
The sea ice at this location was about four feet thick and totally flat on the underside as well as the surface on which we had landed. The sea ice edge itself runs in straight sections or is irregular, even jagged. It all depends on how cracks develop in it, which then develop into ice floes, breaking off and floating away. We had landed near an active working crack at a zig-zag in the edge and the sea ice on the ocean side of that crack was moving up and down about six inches with respect to the sea ice on the inland side of that crack. You could straddle the crack and feel the outer sea ice move up and down.
Emperor penguins and Adelie penguins were swimming both on the surface and underwater as I snorkeled. I watched Adelie penguins swimming fast and porpoising through the water as they swam at the surface. Penguins were darting around in straight lines and irregular paths underwater, dropping down out of my sight into the very deep water below me. I would see them fade out as they dropped down and would also see others coming up fade back into view. The underwater visibility was in hundreds of feet and I could also see very large jellyfish floating slowly with the current. Some penguins appeared to be swimming with no particular purpose and just enjoying a swim with the group. Other penguins made beeline dives down deep to catch fish, krill, or other food. They also seemed to be heading back under the sea ice a lot, possibly to catch fish under the sea ice rather than in the open ocean --- it's hard to say when you are just floating at the surface and watching. The penguins jetted around gracefully underwater and when they put on high speed, their feathers would flatten down and a stream of small bubbles would be released from their feathers, forming contrails behind the penguins. Penguins were jetting around me in all directions, right and left, up and down, front and behind, and some were laying down zig-zag bubble contrails streaming out behind them. The sun was shining brightly and as I looked directly down under me at penguins, sunbeams rayed out and presented a breathtaking scene of clear blue water, with penguins darting around in sparkling sunrays.
After my snorkel session, I really froze in that wind while I got out of my drysuit. Norbert did some topside penguin filming as we hung around for about two hours watching the penguins watch us. They hung around us the whole time, occasionally going for a swim, and then returning to the company of the other penguins and ourselves, for continued sunning and preening of themselves. Penguins are good company - gregarious, curious, respectful -- and I felt a bit sad leaving them as we called it a day and helicoptered away.
| November 30 |
We have been waiting on weather and a helicopter backlog to clear for the last two days in order to go to the Adelie penguin rookery at Cape Crozier. Over the last four days, I did three dives at the grounded iceberg at Cape Barne (previously described) and three dives at Cape Armitage (also previously described). Dives were great fun for me, though nothing extremely newsworthy to report -- unless you are really interested in Antarctic marine invertebrates like me.
One interesting invertebrate: I viewed an extensive bed of Abatus heart urchins, golden brown in color, with the urchins all buried in the sediment with barely anything showing. What makes them especially interesting is that the top of the urchin shell has five deep grooves that the urchin uses to brood embryos and its young urchins. The embryos and young urchins are down in the grooves and covered over by a rim of protective spines along the upper margin of the grooves. I strained hard trying to see little urchins in those small grooves but it would take a dissecting microscope to really peruse them (and not a floating diver underwater).
Another interesting invertebrate: On one dive I collected giant Antarctic isopods for filming. These are related to the sow or pill bug and look like them in general plan but with longer legs, spines all over, and about as big as your hand. These isopods look like something from a 50s science fiction movie . Several of the collected isopods were carrying lots of juveniles on their underside in a translucent pouch. We didn't realize this until one isopod released its young when we transferred it to a holding tank in the lab aquarium. On time lapse filming, one of these isopods grabbed a large spiny polychaete worm and sucked out its insides.
On one dive, I was diving very shallow up near the shoreline at Cape Armitage. A huge sheet of anchor ice (newly formed ice on the bottom) had started slowly rising off the bottom as I passed slowly over it and bumped into me from below. I jumped because one doesn't expect to get bumped during the solitary sort of diving here and the thought of nipping male Weddell seals is never far out of mind. Not only small clumps of anchor ice rise off the bottom to float up and join the sea ice ceiling but also big interconnected sheets of anchor ice as well. I have seen some sheets rising up that are five or six feet across. Whenever sufficient ice forms to buoy up the embedded gravel and organisms and then breaks free, it rises up. The sea ice ceiling has lots of gravel in its icy understructure and a few embedded organisms as well.
| December 6 |
I returned this afternoon to McMurdo from Explorer's Cove at New Harbor on the Antarctic mainland, where we spent three nights. After waiting four days for the weather to clear at Cape Crozier, Norbert gave up and switched our field camp destination to New Harbor.
Since my last report and before our departure for New Harbor, I did two dives at Little Razorback Island. One dive was particularly deep, down to 130 feet, and I spent considerable time just looking around. I described Little Razorback Island previously -- a relatively short shallow bench along its shoreline with a steep tumbling talus slope starting at twenty feet depth or so. Weddell seals cruise under the sea ice along the bench; you are on your own when you dive deeper here. Going down, the talus slope is folded into canyons and is interrupted by rocky outcrops covered by predominantly yellow, tan, and white sponges of various species. Short trees of pinkish soft coral are abundant. Lots of interesting marine invertebrates to see as well as fish here and there. Down deep below one hundred feet, it is very dark with everything in deep shades of gray and black. The sea ice ceiling and the water depth conspire to shut out most of the light filtering down. Down deep, there are rocky cliff sections covered with invertebrate life. I saw big white volcano sponges looming out of the dark; I swam down to one of the larger ones and it was five feet tall on its downhill side and rounded enough for me to stick my head into (though I didn't). I swam a few canyons over looking around and headed back up to find the dive hole.
We helicoptered to Explorer's Cove at New Harbor, the seaside entrance to Taylor Valley, one of the Dry Valleys. The Dry Valleys are sandy and gravelly and have little snow in them ; the glaciers from the Antarctic interior highland cannot pass through their encircling mountain ranges and thus what little snow falls in the Dry Valleys melts away or is ablated. The helicopter dropped us and our gear off at the encampment of Dr Sam Bowser, who studies foraminifers here at New Harbor. The encampment is located just up the beach at Explorer's Cover and is two Jamesway huts interconnected at one end, a science lab hut, and a generator hut. There was a gas stove, microwave oven, sink, tables, cots, etc. The refrigerator is a steel box outside with some snow piled around it. We were quite comfortable and Dr Bowser and crew were very good company.
The diving here was from a heated Jamesway hut about fifty yards offshore on the frozen sea ice. The sea ice ceiling is extremely thick here -- twelve feet or more -- so a dive hole is blasted through the ice and then the Jamesway hut is dragged and set up over the hole. Inside, a heater runs all the time drying out your dive gear and keeping the holes from freezing over. A compressor is available inside to fill scuba tanks with air. Since the bottom is flat and fairly deep, the scuba tanks we used were double 72 cubic foot (cf) tanks for a combined air volume of 140 cf (the usual tank size in the US is 80 cf and I use 95 cf in San Diego). There was even a step down into the dive hole -- a very comfortable setup for Antarctic diving.
Over the course of the next three days, I did six dives, all around 90 to 100 feet depth, for an aggregate time underwater of four hours and thirteen minutes. The bottom was flat and sandy under the dive hut and sloped up steeply far away as one neared the shore. The sea ice ceiling is twelve feet thick with snow and ice cover so it is very dark underwater. The ceiling itself is mostly flat on the underside and in the dim filtered light, it appears mottled in colors of black and deep, dark blue. Looking horizontally, the water looks deep blue-gray - - very dim indeed and it gave me a gloomy feeling compared to the more brightly lit diving I had been doing under thinner sea ice with sea ice cracks with sunlight streaming down. As you swam away from the dive hole at depth, you did not swim far until you could not see the dive hole or the hang line itself in the dim light. The only visual cue to find your way back to the hole is flashing strobe lights attached to the hang line. There were usually three or four of them flashing away; one would burn out its batteries occasionally so you want redundancy in using several. As you swam a good distance away from the hole, the flashing strobes would become smaller points of light until you saw them from far away as pinpricks of flashing light as you scanned the horizon to establish your bearings. Throughout your dive, you glance around to pinpoint the location of those strobes in order to avoid getting too far away and lost.
The bottom was littered with scallops and brittle stars -- zillions of them. The brittle stars were a gray species or a very large orange-red species with body discs as large as the palm of my hand. Some of the brittle stars held their body discs above the sand by holding their arms in an S shape. Others held their arms up above the sand in S-shaped curves. Some laid flat on the sand. Some of the gray brittle stars were moving vigorously forward with a stroking motion of their forward arms. The scallops were almost as big as my hand, reddish-brown in color and were free-swimming; if disturbed, they would open and close their scallop shells and jet up off the sandy bottom. Some scallops had younger, smaller scallops attached to them. Other scallops had stalked sponges and tunicates attached to them. There were a few fish scattered around but clearly the numerical advantage was the scallops and brittle stars.
Big jellyfish with bells about three feet across and with long, long dangling tentacles floated through this dim underwater world. The jellyfish were far above the ninety foot bottom but with such long tentacles, some of the longest tentacles could reach down near the bottom. One jellyfish about forty feet above the bottom had caught a bottom fish with one of its tentacles. I watched as the eight inch long fish struggled, jerked, and swam vigorously in a head-down position trying to break free of the tentacle dangling from the space ship far above us. The fish finally broke free after I watched it struggle for two minutes.
Here and there were a few vase-like rossellid sponges, which had found a few stray rocks to which they could attach on this vast sand plain. Many of these sponges would have feathery white crinoids attached to their upper areas, with the crinoids having their feathery arms spread out for filter-feeding. I also saw a few crinoids directly on the sand bottom. This species of crinoid likes to perch on things for a better position for filter feeding but there are not a lot of perchs available on this sandy plain. Crinoids are also capable of slow movement so they could have been on the move, looking for a place to perch. The sandy plain also had yellow cactus sponges and rumpled-looking ball sponges with spiky tufts sticking out from their bodies for protection. Wherever a stray rock was located on the sand plain, one could see several invertebrate species attached to it --- attachment space was at a premium.
Here and there in the deeper areas, one could see a single-stalked coral-pinkish-red soft coral with short branches covered with polyps. These soft coral are seen erect (2.5 to 3 feet tall) or bent over in a U-shape, with their top branches touching and imperceptibly sweeping the sandy bottom for food. Filter feeding isn't sufficient and these soft coral also graze on the bottom for food. You could decipher their motion by the traces they left on the sand rather than by seeing it with your eyes -- most marine invertebrates here move very, very slowly. I also found a few of these soft coral totally flattened along the bottom. I have read that they move slowly like inchworms to new locations but I would need time-lapse eyes to verify if I was seeing that. I spent dives scouting out the locations of these few soft coral. I made a rough map and then preceded Norbert into the water, guiding him to these soft coral with a flashing strobe light. It is very easy to get disoriented on a dark, sandy plain and our underwater time was limited at these depths, so my scouting role saved him time in finding these soft coral for filming and still photography.
There were a few seastars I would see on the course of a dive. Occasionally I would see one hunched up and over a scallop, opening up its shell and consuming it. I also saw a fat whitish sea cucumber with pointy projections all over its body, with a faint reddish-brown banding around its mid-section. There were large pencil urchins around, with sponges growing on some of their pencil-like spines. There were also dark yellow tinged brown urchins scattered around -- another species of Abatus urchin which broods its embryos and young in spine-protected grooves on the top of its test (shell). There were a few of those long nemertean worms previously mentioned -- not many but they were exceptionally long. I saw one stretched out on the bottom nine feet long, about three fingers wide, with a flattened off-white body (also colored purplish- brown, brown, etc). These worms lay out in the open without fear of predation because they have an acidic (pH 3 !) mucus on their body which keeps them from being eaten.
| December 11 |
Three of the previous four days have been visits to Adelie penguin rookeries for filming. On two successive days, I snowmobiled from McMurdo to Cape Royds to a small penguin rookery there. At about thirty miles an hour, it is a lot of fun to drive a snowmobile (SkiDoo Alpine 2) along the frozen sea ice offshore Ross Island and heading north to Cape Royds. The air is nippy at speed but bundled up, it is an invigorating ride. Cape Royds is where Ernest Shackleton's hut is located and I had an opportunity to look inside at the period furnishings. It is smaller than Scott's hut at Cape Evans and has an impressive iron stove inside. It is also built near an Adelie penguin rookery so they had game and eggs in season.
The penguins are nearing the end of the egg incubation period; the male and female take turns sitting on two eggs on a pebble nest. Skua birds were heavily attacking the Royds rookery on one visit. We watched them pester the penguins to raise up off their nest and then dart in and grab an egg. A skua would fly off with an egg in its beak and then usually share it with its mate. One study estimated that nine percent of eggs were lost to skuas at a specific rookery. Skuas are very patient waiting for an egg-stealing opportunity; they sit very close to nesting penguins, watching for an opening. The penguins usually stand up and stretch and nudge their egg around a bit every once in a long while. In addition, they stretch up and peck at skuas hovering low overhead which presents another opening. The penguins raise quite a commotion when a skua is in the midst of their nests and on the prowl.
The skuas themselves nest on the ground just outside the penguin nesting area, screeching when you walk to close to a nesting skua. If the mate is nearby, it will dive bomb you and swoop down very near the top of your head, trying to run you off. I always feel like stomping all over skua eggs and helping out the penguins but that would interfere with the natural order.
We helicoptered one day to the north end of Ross Island to the Cape Bird Adelie penguin rookery. We situated ourselves along the shoreline for filming penguins jumping into the water and hopping out. The penguins obliged as we watched lots of them do so. One group was incredible. They were reluctant to go in and were on a steep and short ice cliff above the water; when they did go in, it was like watching Nature's bloopers. One penguin fell head first down the ice, bumped off a ledge, spun around, and went in tail first. Another penguin got pushed off the cliff by an anxious penguin behind it, performing an ungainly water entry -- a sideways flop. Several others toppled into the water with not a single graceful swan dive among them. The weather has been sunny with a light wind so it has been enjoyable spending seven hour sessions at these penguin rookeries.
On another day, I did a final scuba dive at Cape Armitage -- it was fun to take a last look around. Last night, I hiked up Observation Hill next to McMurdo with Dale and Dave. Observation Hill rises steeply above McMurdo Station to a height of 750 feet, with a fine view in all directions. Looking north, you can see Mount Erebus, the high point of Ross Island on which I stand, with its steaming volcanic peak. Observation Hill has the original memorial cross dedicated to those who lost their life returning from the South Pole on Scott's Antarctic expedition; it is made of heavy Australian jarrah wood timbers that the expedition members dragged up this very steep hill. It was sunny and calm on top of Observation Hill. You could see Scott's hut on the point next to McMurdo Station, built by Scott's first Antarctic expedition and used in his second expedition as a waystation.. From Observation hill, looking south, you could see the southerly direction taken to the pole by the exploring Antarctic expeditions of Scott and Shackleton. It was impressive to see the scale of the distance and relative emptiness faced by these explorers. Far off, I could see the crinkled transition between the fast annual ice and the permanent Ross Ice Shelf -- their first dangerous passage as they headed south. Even farther away, I could see Minna Bluff, on the shoreline of the Ross Ice Shelf, marking their route to the South Pole. Not for me -- I came to scuba dive !
Far below, we could see the activity surrounding the moving of McMurdo air operations from the annual ice runway to the permanent ice shelf runway location farther in on the Ross Sea. They shift runway operations from the fast annual ice close to McMurdo Station to the permanent ice shelf much farther away from McMurdo; they have to do that well before the fast annual ice starts weakening in the weeks before it breaks up. We are slated to take off from the permanent ice shelf runway (Williams Field) for the 7.5 hour flight back to New Zealand. Though scheduled to leave on a specific day, one may get delayed a day or so in departure as passengers and cargo get weighed and reconsidered (or if the weather turns for the worse).
| Text ©Peter Brueggeman.
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Click to see the
Diving Under Antarctic Ice web site resulting from this trip. DUAI presents a photo gallery, scuba
diving information, a Field Guide, and personal journals based on the work
of Norbert Wu's underwater photography team in McMurdo Sound.