Authors: John H. Wright
“Over here is GAW,” I pointed to the four-by-four-inch post. “Everything past that is bad news, and nobody goes past GAW unless I know about it. That's where the Shear Zone lies. Out there, where all those flags are.”
More than a hundred flags stood in a bamboo forest, three-quarters of a mile away. A line of green flags led into that thicket. They marked the left side of our road.
“All those other flags out there, the black ones and the red ones, mean something. We'll tell you what they mean when we go out there. For now, if you remember nothing else, remember this: the green flags will lead you to safety. If you get out there in a blinding snowstorm and need to get back, go from green flag to green flag.”
“Got that,” Kim drawled. “Green is good.”
The wind slacked, dropping the airborne snow out of it. Towards Mc-Murdo, a wall of low gray clouds snarled over the surface. But here, a brilliant blue sky with clear horizons in three directions cheered us. We trudged around the camp area.
“And over here, this black plywood teepee-looking thing, that's our crapper. It's generally warm in there. Do your thing in a plastic bag in the bucket, then put the bag in the open drum behind the teepee. And that flag standing next to it, all by itself, that's where we pee. It doesn't look like it now, cause the ground is covered in drift. Pee there. Don't want any yellow snow anywhere else in camp because we melt the clean stuff for drinking water.”
“Yellow snow over there. Got it,” the cat skinner drawled again. Tom nodded, his keen blue eyes showed he, too, was taking it all in.
A line of black flags stood a couple hundred yards north of the camp perimeter, not toward the Shear Zone but in the direction of Mount Erebus, which towered over us even here.
“That's downwind generally. We've searched the ground up to those black flags. No crevasses found,” I explained to Kim. “There's where you put the snow you're about to push out of camp.”
“Black flags are bad,” Kim nodded. “You want me to feather the snow out or pile it up?”
While the bulldozer warmed, Kim walked around his machine, chatting with Russ before he climbed into the cab. Shortly the bulldozer snorted, raising a puff of smoke, and crawled forward. The rest of us grabbed shovels and started digging out around the small stuff in camp.
The air grew uncommonly still, and the bright sun warmed us. Those of us with shovels shed our jackets while we mucked out small nooks and crannies packed with drift snow. Kim pushed our work away with the big piles he carried in front of his blade. In three hours, we had a level campsite again.
Tom and Kim explored their new surroundings while I heated up leftovers begged off the McMurdo galley and raised Helo-Ops by the radiophone.
“We're scheduled for off deck in a couple hours,” Shaun explained from his end at Helo-Ops. “The antenna is in the basket. We tested it over the Castle Rock loop. It works perfectly. The pilot wants to know, how things are looking at camp?”
“Congratulations. We're mucked out and level. Blue skies overhead. The flags I'm looking at out this window are limp. Do you have ETA our location?”
“2000 hours. The pilot would like to land first in the camp perimeter and shut down. He needs to get oriented to the project.”
“Understood. You take care of his orientation. And I do want you to fly in the chopper when Allan's running the radar. You may spot something in no man's land that'll be useful.”
Russ, Kim, and Tom warmed expectantly by the heating stove and understood the good news heading our way. Tom asked if we had a position on the post at GAW.
Puzzled, I explained that the surveyor had been out a couple weeks before and had captured a very good position with differential GPS. I rummaged through a stack of paper next to the radiophone, found the coordinates, and handed them to Tom.
He wandered over to GAW, while the rest of us rolled a drum of aviation fuel across the yielding snow to a fifty-foot circle of red flags. We'd pushed the poles down so far that only their banners remained above the surface. It looked to us like a landing zone should look.
Tom meandered back over to us. “I think GAW has moved maybe forty feet since the surveyor was here. I can't tell exactly, but I'm certain it's moved.”
I spotted the hand-held GPS unit Tom had. “How long did you occupy it?”
“Long enough.”
Tom's finding opened a flood of possibilities. Nobody had moved the post. We knew the Shear Zone ice was moving north, but we'd not measured that yet. The surveyor's recent work was only our start. The green flag line through the Shear Zone would be part of it, too. Now Tom suggested the ice was moving three feet a day. That tweaked the pattern we imagined flying in the next hour: the pilot would fly to coordinates for HFS we'd captured over a month ago.
“Nothing we can do about it now,” I shrugged. Tom agreed.
The
whocka-whocka-whocka-whocka
of an approaching helicopter also agreed.
The helicopter circled our camp, and then slowly, slowly dropped into the nest of red-flags. Heels first, then toes, its skids shimmied onto the soft snow. Billows of it pelted our faces. The engine whined. The rotors slowly turned to a stop. Our radar antenna looked down through a square hole cut in the bottom of its cargo basket.
“Nice job.” I complimented as Shaun and Allan climbed out. Then recognizing the pilot who'd helped me locate a traverse route across McMurdo Sound years ago, I smiled in greeting. “Thanks for coming, Mr. Scott Pentecost.”
“You bet. This is pretty neat out here. Good LZ, too,” he declared, referring to our landing zone. We'd crossed paths recently at a Colorado gas station, he on his Harley, me in my truck, both of us going somewhere else.
“Allan, everything working for you?”
“Everything works fine,” he said, not a word wasted.
They declined our offer of refreshments for the moment. Shaun gave Scott the briefing, and the three of them started the radar survey right away. We thrilled at watching the chopper zoom fifty feet off-deck over no-man's land.
We gathered inside the warm Jamesway when they landed back in camp.
Allan pulled a metal folding chair across the floor and slouched firmly in it, stretching his legs to relieve his helicopter cramps. I pulled up another
chair and leaned forward, elbows planted on my knees. The others stood still, listening.
“We have completed seven flights from GAW to HFS,” Allan reported. “One right down the line, two south of the line, and four north of the line. We have recorded the radar record of each flight, tagged at intervals with GPS coordinates.”
I nodded. I got the picture.
“However,” Allan went on, “I believe for windage and other considerations, some of our lines overlapped each other, particularly at the eastern or far side of the Zone. We had no reliable ground reference there to guide us.”
I nodded again.
“It appears that where you are now with your road lies right in the worst of itâthe most crevasses, in the densest cluster.” Allan sketched a rough diagram in my logbook. My heart sagged.
He allowed that the southernmost flight line showed fewer crevasses, though he could not estimate their numbers yet. But all of the flight lines showed the densest cluster lay within the first mile and a half from GAW. Beyond that he reported an area free of crevasses for two-thirds of a mile, then another half-dozen crevasses, and then another clear area.
Finally, he explained, “There are crevasses right at HFS, but for a mile beyond that there are none. I believe that HFS is truly
home free
and once you are past there, you are across the Shear Zone.”
Our road work had reached Crevasse 6, three quarters of a mile from GAW. Another three quarters might see us into that first crevasse-free area.
“Let's call that the Miracle Mile. We got to call it something. Allan, I understand your report. It's tremendously valuable. I'm not happy to learn we're in the worst ground the Zone has to offer, but I'm delighted to learn the Miracle Mile is in front of us. Tell me ⦠do you see any meaningful,
qualitative
difference between any of your flight lines?”
An exceptionally good listener, Allan pondered before answering. His eyes dropped to the floor. Some time passed while he considered “qualitative” and the import of his answer. When he looked up, he said simply: “No.”
That settled it. We'd go forward from where we were, in the worst of it, and hope for a happy arrival at the Miracle Mile. We wouldn't change course from straight ahead.
I walked Allan and Scott back to the helicopter. Allan would join our camp after he processed his data in town. Shaun stayed with us.
We shot the bridge at Crevasse 5, and gave Kim his first taste of filling a crevasse. He learned the meaning of the flags, the boundaries of the fill-gathering area, and where the spotter would stand. “Watch him as you come up to the edge. He's looking into the void that you cannot see,” I told him.
When Kim filled 5 to the brim, he parked his machine proudly over the plug he'd just stuffed into it. “I see what this is all about now,” he declared.
Moving on to 6, we set up our new hot-water drill and drilled more holes there than we really needed. Russ grinned with glee. Shaun and Tom prospected past us with the PistenBully and found 7 and 8.
Back in camp, we prepared for a trial run to HFS. I wanted to run the same transect with radar on the ground that we'd flown, but I wanted to prove we could do it safely. “Safely” meant without falling into a crevasse.
Shaun rigged a train of two snowmobiles with a Nansen sled roped between them. Those sledsânamed for Fridtjof Nansen, Amundsen's Norwegian championâwere beautiful relics of bentwood and rawhide lashings. The whole sled measured twelve feet long and two feet wide. They flexed marvelously over any uneven snow surface, offering a stable ride to passenger and cargo alike.
Shaun and Tom had experience running trains like this one. Allan did, too. Russ, Kim, and I were more at home running tens of thousands of pounds of diesel-fueled equipment. I told Shaun, “Show me,” so Shaun manned the lead snowmobile and Tom the rear one while I rode the Nansen as monkey-in-the-middle.
When our train circled the post at HFS, I had been shown. We didn't know how many crevasses we'd just crossed, nor where they were. We didn't fall into any of them.
From HFS, we could not see our camp. But standing atop one of the drums next to the post, I did spot it. And from that perch, I studied our tracks highlighting the surface. We'd crossed rolling country, no longer an unmarked white expanse. The rollers might be ten feet high, perhaps a quarter-mile to the crest of the nearest one. That was new knowledge, though I didn't know what it meant.
Russ and I returned to McMurdo that evening to retrieve Allan. We had him back in camp the next morning. Allan would ride the Nansen sled that afternoon.
After lunch, Kim, Russ, and I dragged the hot-water drill and a load of explosives out to Crevasse 6. Russ rode playfully upon the drill sled, now a well-warmed seat since he'd already fired up the hot water maker.
The snowmobile train started out of camp toward us, swerving to miss the drill we'd set up squarely in the middle of the road. First Shaun steered past us in a raucous yellow-and-black machine. It pushed a makeshift boom bearing the radar antenna. Shaun never took his eyes off the ground ahead. Behind him, a taut cotton rope bounced lightly over the snow. Alongside it, a black signal cable and a slack belay rope slithered by. Then the Nansen sled whispered past. Aboard it, Allan lay covered in wool blankets, his head and upper body shrouded in a cardboard box. Underneath all that he stared at a computer screen. Behind Allan's Nansen another knotted cotton rope, paired to another belay rope, snaked over the snow. Finally, Tom's snowmobile buzzed by, bringing up the rear.
“Look at how Allan's all trussed up ⦠can't see where he's going.” Kim remarked.
“Maybe he don't want to see,” Russ added slyly, as the train disappeared into the east.
The radar survey to HFS came off without incident. The next day, Allan produced color printouts of it. Pages taped end to end made a scroll.
“We haven't seen images like those,” I commented on the inverted, parabolic forms. Some were hourglass-shaped.
“I've changed the radar settings,” Allan explained. “I'm not looking as deeply as you were, and I've increased the radar gain for the top five meters.”
He pointed out half a dozen hourglass images that lay near HFS. Working backward, he scrolled through several pages showing flat, undisturbed stratigraphy. “That's the Miracle Mile,” he explained.
“How about the road we've built so far?”
“You've gone over some features that I would like to look at more closely.”
“Right. We've some questionable areas out there ourselves. But we've crossed them with the D8 already.”
“That's good.”
We shot the slot at Crevasse 6 in the morning, and prospected for a fill-gathering area south of our road. Mindful of Allan's claim that we were working in the worst of it, we took our time doing this. In the end, our flags and PistenBully tracks marked an irregular snow farm where the bulldozer would have no straight pushes.
I planned to head out with Allan in the PistenBully after lunch, to show him how we searched the area, and to see how he'd changed our radar settings.
“I'd like that very much,” Allan said with a nod.
The bulldozer idled near Crevasse 6 in the clear afternoon. Both snowmobiles and the hot water drill were up with us, and the PistenBully was rigged for radar. For everyone's benefit, I reviewed the boundaries of the fill-gathering area and the flags and vehicle tracks surrounding it. Tom stayed at 6, spotting for Kim.
Taking a looping route around Crevasse 6, we dragged the drill up to 7 where Shaun and Russ would make holes. Allan and I went on in the Pisten-Bully to fill in the chessboard around 8.