Hell Holes: What Lurks Below, Page 3

Alaska Map with Route to Hell Hole

  We arrived outside the designated hangar on the private charter side of the airport within minutes of each other: Angie and Jill in our cars and Mark and I in a university van carrying the ground-penetrating radar, seismometers, portable drill for taking core samples, and the other gear we thought we might need. We pulled up to the open luggage compartment of the executive jet with the red, white, and blue ExxonMobil logo on its side. Mark and I loaded our luggage and equipment, while our wives boarded the plane.

  Once everything was stowed, I followed Mark up the short stairs and into the lavish interior of the business jet. Unlike the cramped commuter planes I usually took when flying up to the oil fields, the Embraer Legacy 500 made first class seem like coach. Either the executive funding our study was desperate to get us up there, or this was the only aircraft the company had left to send. Either way, I was happy for the unexpected upgrade.

  Unlike typical airliners, the jet’s eight large leather seats were organized around four small tables, two on either side of the cabin. Each table separated two seats, one seat facing the back of the airplane and the other facing forward. Angie and Jill were seated in the first row of the plane leaving the second-row seats facing forwards for Mark and me. I’d just sat down opposite my wife when she pointed her finger over my shoulder. Following Mark had prevented me from noticing the unexpected extra person seated in the rear of the cabin. With the satisfied smile of a cat having feasted on canary, there sat Aileen O’Shannon. I wondered whether Angie and Jill had selected this particular seating arrangement so they could glare at the weirdly bewitching beauty in the back. Of course, it may have been to keep Mark and me from being tempted to look at her instead of paying proper attention to our wives.

  I got up and marched straight to the rear of the plane and said, “I’m sorry, but I never said you could come along on this trip.”

  “You are?” she asked coyly. “Oh, my. You never said I could not come.” She gave me a stunning smile that I’m sure usually got her everything she’d ever asked for. “I naturally took your silence to signify agreement, so I packed my bag and cameras, and here I am. Lucky for you that I did; you wouldn’t want to get up there only to realize you needed someone to make a visual record of your discoveries. Besides, I know some of the discoveries the Russians made that they didn’t publish.”

  The co-pilot walked up behind me. “Excuse me, Dr. Oswald. Can you please take your seat now? We’re on a very tight schedule, and Mr. Kowalski wants you in Deadhorse as soon as possible.”

  I looked up front and saw that the cabin door was already closed, and the seat belt signs were on. Before I could answer, the plane began taxiing away from the hangar. Realizing that it was too late to rid ourselves of the reporter, I turned around and took my seat facing Angie.

  “I see we still have Miss O’Shannon with us,” Angie said with a hint of irritation. “I thought you’d decided we didn’t need her.”

  “I did,” I answered as the plane accelerated down the runway. “But the cabin door was already closed, and we were already moving.”

  “Jack, you’re the leader of this study, and this plane wouldn’t even be here if it weren’t for you. The pilot would have turned around if you’d asked him to.”

  “You’re right,” I admitted sheepishly, silently cursing my habit of not questioning authority figures, at least not unless it involved science.

  “Well, what are you going to do about it?”

  Suddenly and for no apparent reason, my annoyance with O’Shannon disappeared, and I felt an overpowering desire to keep her with us, with me. I twisted around and looked back at her. She was staring back at me with a knowing smile. God, she looked so mesmerizingly beautiful as her fingers provocatively played with the top button of her shirt. Of course, she should come…

  “Jack… Jack!”

  I jerked back around, my heart pounding as I felt my face warming. I was blushing from embarrassment and guilt. I was also confused, unsure of what had just happened.

  “Jack, I was talking to you, and you just ignored me! What’s gotten into you?”

  “Uh… Nothing,” I lied. What had gotten into me? “I’d ditch her in Deadhorse, but I think she’d just rent a car and follow us. And as much as I hate to admit it, I’m beginning to think it’s best if she comes along. We’re going to be very busy the next couple of weeks, and I’d just as soon not be bothered by having to stop and take pictures of what we find. Who knows? Maybe she does know something interesting that the Russians didn’t publish.”

  “Assuming of course that she’s actually been to Siberia and isn’t lying through her teeth to get a free ride up there, not to mention access to the holes and our research,” Angie replied. “But I’ll put up with her as long as she doesn’t get in the way and you keep your eyes on your work.”

  “Angie, are you jealous?” I asked, surprised at her uncharacteristic reaction.

  “Of course not!” she replied. “It’s just that there’s something strange about her I can’t put my finger on. I get the impression that she’s hiding something. Besides, she seems like the kind of woman who enjoys wrapping men around her little finger and doesn’t care whether they’re married or not. You know I totally trust you, but that doesn’t mean I want to watch her try to work her magic on you, and I’m sure Jill feels the same about Mark.”

  Thankfully, Jill interrupted us by reaching over and handing me a large envelope. “The pilot asked me to give you this.”

  I opened the envelope and pulled out a letter from Kowalski with the job description, a standard consulting contract, a dozen pictures of the holes, a map with their positions labeled on it, initial reports from company geologists, and a thumb drive that I assumed had electronic copies of what he’d provided in hard copy. I spread the pictures out on the table between us so that Angie and I could look at them.

  “Look at the size of this hole,” she said, pointing to an 8 by 10 inch photograph that had obviously been taken from the air. “I didn’t realize how big it was until I noticed the a pair of musk ox standing next to it. It has to be a couple hundred feet across and nearly as deep.”

  Alternating layers of soil and lenses of ice were plainly visible where sunlight illuminated the top fourth of the hole. The very bottom looked like it might have been covered by water, but it was too dark to tell for sure.

  “Where’d all of the earth go?” I asked, completely stumped by the enormous size and strange shape of the crater. Essentially circular with smooth vertical sides, it looked like a giant had taken a huge cookie cutter and dug out a titanic-sized drum of dirt. Also bizarre was the fact that only a tiny amount of loose soil ringed the perimeter of the pit. Whatever it was, it certainly didn’t look like a normal sinkhole or the remains of a melted pingo. In fact, I had no idea of what could have caused it.

  After passing the photos over to Mark and Jill, we looked at the map. I counted 26 holes running from the National Petroleum Reserve to the Arctic National Wildlife Refuge and from the Brooks Range to the coast. Most were close to the coastline. Sixteen were in areas with active oil wells, and one hole – a little farther south than the others – was within a few miles of the Trans-Alaska pipeline.

  By the time we were done with the photographs and map and had skimmed the preliminary reports from the company geologists, we were just leaving the Brooks Range and beginning our descent into Deadhorse.

  The pilot came on the intercom and informed us that we would be flying over two of the holes during the last 10 minutes of our flight. Each time we approached a hole, the pilot put the plane in a sharp bank and flew completely around it in a relatively tight circle. Even though that gave us an excellent view from all sides, the relatively featureless tundra made it impossible to estimate the holes’ sizes and the low angle of the sun cast dark shadows that hid their bottoms from view.

  Looking at aerial photographs was one thing; actually seeing the holes with our own eyes was something altogether differe
nt. It seemed that the more I learned about the holes, the less I understood them. We were not going to discover their cause from the air.

  We touched down on the Deadhorse airport’s single runway and taxied over to the private hangars used by the oil company planes. Our plane rolled to a stop next to two Range Rovers and a Ford Raptor pickup truck towing a small trailer for our equipment.

  Kowalski was waiting next to the vehicles. Short, with thinning brown hair, and the belly of a man who spent his time behind a desk instead of in the field, Kowalski was in his early sixties. In the past, he had always been immaculately dressed in an expensive three-piece suit and tie. Thus, I was only somewhat surprised to see that he wasn’t properly dressed for fieldwork. Instead, he was wearing business casual: black dress shoes, pressed khakis, and a button-down shirt under his jacket.

  On the other hand, I was very surprised to see that Kowalski was smoking a cigarette. He’d had a scare a couple of years previously when doctors found a spot on his chest x-ray. Though the biopsy revealed that the mass was benign, he’d vowed to quit, and he’d been quite proud of himself the previous summer when he told me he hadn’t had a smoke in six months.

  A much taller man exited one of the Rovers as we stepped off the plane. In contrast, the stranger was perfectly dressed for the wilderness from his weather-beaten hat down to his well-worn boots. He stood six-two and had the rugged build of a former oil roughneck. Younger than Kowalski, he was in his late forties or early fifties and sported a short black beard and mustache.

  “Welcome to Deadhorse, Dr. Oswald,” Kowalski said as we approached. “This is William Henderson, one of our wildlife biologists. He’ll be watching our backs and protecting us from any polar bears, wolves, or other animals that might interfere with your research.”

  “Dr. Henderson,” I said, shaking his hand. His grip was firm but not excessive like those of some oilmen I’ve met; he had the handshake of a man comfortable in his strength with nothing to prove by squeezing harder than necessary.

  “Call me Bill,” he replied. “Just a masters, I’m afraid. Could never quite justify the time and expense of going for my doctorate. Besides, I’d rather spend my time outdoors than indoors studying or teaching classes.”

  “This is my wife, Dr. Angela Menendez,” I said, motioning to Angie. “She’s our climatologist and will be helping us determine whether the exceptional warming we’ve been having up here the last couple of years has caused the holes. This is Mark and Jill Starr, two of my grad students, who will be helping us take measurements and also take care of the equipment we brought.”

  Having given my full attention during our flight to the information Kowalski had provided, I’d managed to forget our fifth wheel who’d sat quietly in the back of the plane during our flight from Fairbanks.

  “Hello Mr. Kowalski,” she said, stepping forward and extending her hand when she realized I wasn’t going to introduce her. “I’m Aileen O’Shannon. I’m here to photograph the holes and make a visual record of our findings while we’re in the field.” She shook Kowalski’s hand, holding it a few seconds longer than necessary and smiled. “I hope you will find some time to tell me all about the important work you do up here.”

  I’m sure that Kowalski was beginning to blush when O’Shannon turned to our field biologist. “And it is a pleasure to meet you too, Bill,” she purred, placing her left hand on top of his right as they shook hands. “I’m sure I speak for everyone when I say we all feel safer knowing you are watching our backs.”

  “Miss, the pleasure is definitely all mine,” Bill replied, his expression making it clear that he would be more than happy to watch any part of her.

  Angie leaned over. “Care to guess whose back he’ll spend the most time watching?” she asked, whispering into my ear.

  “Nope,” I whispered back. “And the way she just hooked and reeled in Kowalski and Bill pretty much settles the matter of her status. We’re just going to have to get used to having her with us for the duration.”

  “Maybe so, but that doesn’t mean I have to like it.” Angie replied. “Just look at her. Who the hell prepares for a week in the field by having herself made up to look like a model on a fashion magazine photo shoot. No, her story’s nothing but a load of bullshit! Her spending time in northern Siberia is about as likely as me being wined and dined by the Koch Brothers.”

  I glanced over to where Kowalski and Bill were vying for O’Shannon’s attention. I hadn’t noticed, but now that Angie pointed it out, I realized that our reporter did look more like a supermodel than someone ready to spend a week living out of a tent on the North Slope of Alaska.

  Kowalski interrupted my train of thought by saying, “I’m sure we’re all anxious to get started. Let’s load up, shall we?” I was annoyed to see him casually flick the rest of his cigarette onto the tarmac, where it gave off a thin stream of smoke. It always bugged me how smokers seem to think it’s okay to use the world as their ashtray. I nearly said something, but then thought better of it. It doesn’t pay to publicly point out the failings of the person providing your paycheck. I waited until Kowalski wasn’t looking and then walked over, picked up the now dead butt, and tossed it in a nearby garbage can.

  Mark and I transferred our equipment from the plane to the trailer that held the tents and other supplies ExxonMobil had provided, while Angie, Jill, and O’Shannon loaded our luggage and backpacks into the back of the Range Rovers.

  “It’s almost two,” Kowalski noted as he glanced down at his watch. “Did you all have time to grab lunch before you left? Maybe we should have a late lunch here in Deadhorse. That way, you can get right to work once we arrive on site.”

  “Mark and I grabbed snacks from the vending machine in the geology building,” I answered. I looked over at Angie and Jill.

  “I had an apple and a yogurt,” Angie replied.

  “I had some crackers and cheese, but it wasn’t much. I wouldn’t mind eating again,” Jill added.

  “Between packing, talking my boss into letting me come, and tying up a few loose ends, I am afraid I completely overlooked lunch.” O’Shannon said.

  “Okay,” Kowalski said. “We’ll stop at the Prudhoe Hotel for a quick lunch on our way out of town.”

  We left the tiny airport, and five minutes later, we pulled into the hotel’s parking lot. Once in the restaurant, Angie and Jill steered Mark and me to one table while Bill and Kowalski happily sat with O’Shannon at another. As we were finishing our meals, my wife noticed the reporter get up and put on her coat.

  “I wonder where she’s going,” Angie said as the photojournalist walked past our table on her way to the door.

  A few minutes later, we let Kowalski pay the bill and headed outside. O’Shannon was standing by our vehicles, talking on the phone.

  “Debeo abire nunc. Et veniunt. Et loquar ad te postea. Vale,” she said, quickly ending the call and putting her phone back into her purse.

  “Italian?” Angie asked. “Our photographer is full of surprises.”

  “Latin,” O’Shannon corrected, having overheard my wife’s comment. “One of my younger brothers recently moved to Rome to complete his training. He says practicing with me is helping him master the language.”

  “Oh, your brother’s studying to be a priest.” Kowalski concluded. “That’s wonderful. My uncle was a priest at Saint Raphael in Fairbanks before he retired. Perhaps you knew him.”

  “No, I am afraid not,” O’Shannon answered. “I have not attended mass since I was a child. Fortunately for my brother, however, I have never forgotten the Latin I learned in school.”

  I wondered how her younger brother ended up a priest given her family had apparently left the Church when she was so young. I sensed there was an interesting story there. However, she turned, climbed into the Raptor, and shut the door, putting an end to the conversation.

  Forty-five minutes later, we were caravanning south down the Dalton Highway. We were heading towards a large hole that had appeared unc
omfortably close to the Trans-Alaska Pipeline, which carried North Slope crude to the Valdez Marine Terminal where it was loaded onto giant tankers for transport around the world. I led the way with Angie and Kowalski in the first Rover. Mark and Jill followed in the second Rover, and our biologist and reporter brought up the rear in the Raptor.

  The fifty-six mile drive was uneventful except for the large trucks that occasionally barreled past us going in the opposite direction on the narrow two-lane highway. Dotted with ponds and small lakes, the tundra was a beautiful green in late summer. We occasionally saw isolated musk ox or a lone caribou in the distance or crossing the road. The Trans-Alaska Pipeline paralleled the highway some distance away on our left. Typically raised eight feet above the ground on its vertical supports to prevent it from melting the permafrost, the pipeline was high enough for the caribou to cross under. Just past the pipeline, the Sagavanirktok River, or the Sag as most people called it, ran north to the Arctic Ocean.

  Fifty miles south of Deadhorse, we passed Pump Station 2, an unmanned complex of ten buildings, a huge satellite disk, and a large oil storage tank. One of 11 such stations along the Trans-Alaska Pipeline, it had once helped pump oil south to Valdez. No longer needed, it was mothballed and placed on standby status in case it might someday be needed again. Kowalski remarked that it had the last indoor toilet along the highway this side of the Brooks Range. Just past the pump station, the road bent to the southwest, away from the pipeline and the river.

  Four miles further down the road, we came to the spot where the Dalton Highway came closest to the hole that was our first destination.

  “You can pull off here,” Kowalski said, looking at his GPS receiver. “The hole is about one and three-quarters miles northwest of us.”

  “Where?” I asked, slowing down to look for an access road to take us to our destination.

  “Right here.”

  I put on my turn signal to warn the others, slowed, and pulled off the side of the elevated road. I inched forward onto the marshy tundra as far as I dared to avoid rocks thrown up by the big rigs that would be barreling past while we were gone. “How far did you say it was to the hole? Some of our equipment is kind of heavy; I wasn’t planning on having to lug it cross country.”

  “Sorry,” Kowalski apologized. “I was originally hoping to get one of our helicopters, but they’re all being used looking for more holes and checking the pipelines for damages. That’s why I chose this one; it’s the closest hole to a road. And don’t worry about the regulations against driving across the tundra before it’s frozen. The company will pay any fines. Just drive nice and slow, and stick to the highest ground you can so we don’t get stuck. Otherwise, we really will end up having to carry your equipment. Either that, or do without.”

  I put our SUV back in gear, and carefully drove out onto the tundra. Our four-wheel off-road vehicles had no trouble driving over the gently rolling ground, though it was touch and go crossing two tiny streams that flowed north to the Arctic Ocean. Sinking several inches into the soft, wet soil of the streambeds, the cars left muddy ruts that marked our passage towards the giant pit.

  Ten minutes later, we came over the top of a gentle rise and saw it, a huge hole that seemed totally alien and out of place in the featureless tundra. After driving around the hole, I found a dry spot and parked our car next to where we would make camp. The hole was seventy yards away to the northwest: close enough to walk to with our equipment but far enough away to avoid the risk of the weight of the cars causing the side of the hole to collapse.

  Once we’d stepped outside our vehicles, Bill handed out the compulsory cans of insect repellent. “Better put this on,” he said. “Although it’s mid-August, and the mosquitoes don’t swarm much after the end of July, there are still more than a few of the little vampires that would happily suck us dry, not to mention all the black flies that love taking little nips out of any exposed skin.”

  “Bill, would you be a dear and please spray me where I can’t reach,” O’Shannon asked. She turned her back to him and used both hands to lift her long, fiery curls from her neck.

  “It would be my pleasure,” he replied. Given the time he allocated to the task, it seemed clear he believed the mosquitoes and flies would be particularly attracted to her.

  Scowling at O’Shannon’s obvious manipulation of Bill, Jill handed Mark her can of repellant. “Spray my back,” she ordered and turned around. Taking the hint, I quickly offered to spray Angie and then made a point of not looking at O’Shannon while my wife returned the favor.

  Once protected from attack by Alaska’s famed flying bloodsuckers, we walked over to the hole to get a better look. It was much bigger than I’d expected, roughly 100 yards in diameter and nearly 230 feet deep. That made it roughly the same diameter as the largest of the Siberian holes, but at least two to three times deeper. The exact measurements would have to wait until we unpacked our surveying equipment.

  An uneven ring of loose dirt, as high as my waist and twice as wide, surrounded the pit. Just inside this circular mound of muddy earth, the top few feet of ground had thawed, loosened, and slid into the hole, producing an incline of 45 degrees before angling straight down to the bottom

  The thawed layer above the permafrost was primarily silt saturated with the water from the frequent summer rains. Seepage had washed tiny gullies into the soft dirt, forming thin streams that ran down the walls. Farther down, the smooth sides of the pit remained frozen, kept that way by the dense cold air trapped in the hole.

  “Damn,” Mark said, inching his way closer to the ring of dirt for a better look. “That is one big hole.” He was just about to step onto the encircling ring of loose dirt when Jill yelled, “Stop! Mark Starr, don’t you dare get any closer until you’re in a climbing harness that’s properly roped to the winch.”

  “Okay, Jill,” he answered sheepishly. “But Baby, you’ve got to come up here and see this.” He waved her forward, and she slowly advanced until she stood next to Mark, who put an arm protectively around her waist.

  The rest of us carefully crept closer until we stood in a row parallel to the edge.

  “Doc, have you ever seen anything like this?” Jill asked with a nervous tremor in her voice. “The photographs of the Siberian holes don’t do it justice.”

  Our reporter-turned-photographer grimaced at the unintended slight of her work as she raised her camera and began taking pictures.

  “I don’t see how global warming could have caused this,” Jill continued, pointing to the side of the hole. “Even though the top couple of yards have thawed, and that’s about four times deeper than it should be this far north, the rest of the hole is clearly frozen all the way down to the bottom.”

  “Is the permafrost layer usually this deep?” Bill asked. “I thought it would only be frozen 50 feet down or so.”

  “It varies depending on how far north you are,” Jill replied, naturally taking on her role as teaching assistant. “Down in Fairbanks, the ground’s actually frozen down to about 150 feet. It’s about a fourth of a mile deep where we’re standing, and up at Prudhoe Bay it reaches down some 2,000 feet below the surface.”

  “That’s got to be what’s keeping the nearly vertical sides of the hole from collapsing,” Mark said, clearly impressed by the strange cylindrical shape of the hole.

  “Still in spite of the record temperatures the last couple of summers,” Jill continued, “it’s surprising to find the ground has thawed even six feet down, when it shouldn’t be more than a foot and a half. That’s got to have an impact on methane production. We’re going to have to re-measure the depth of thawing and factor that into our climate models.”

  “You’re right, Jill,” I replied. “I’ll help you put together a grant proposal once we’re back down in Fairbanks.”

  “Just remember that we’re not paying you to study climate change,” Kowalski interjected. “You’re here to determine the risk posed by these holes to our wells and pipelines, not to work on y
our climate models. Every minute spent on something else is a minute we don’t have to waste.”

  Kowalski finished his cigarette and dropped the butt onto the soggy ground. I silently vowed to come back later and pick it up.

  “But the increasing temperatures may be part of what’s causing the holes,” Mark said, coming to his wife’s defense.

  “I fail to see how a little extra melting at the surface could be causing such deep holes or explain where all the ground’s gone, for that matter,” Kowalski said, his increasing irritation clear in his voice.

  “You’re right, of course,” I told Kowalski before Jill or Mark could say anything more that might upset the man signing the check. We needed every dollar we could earn during the summer vacation to pay for new equipment and fund our research during the rest of the year. “We’re here to study the holes and find out what’s causing them.”

  We set up our seven tents: one for Angie and me, one for Jill and Mark, one each for Kowalski, Bill, and O’Shannon, one for our supply tent, and another for our equipment. Then we unpacked our equipment and set off to measure the hole. I set up the tripod and mounted a theodolite for accurately measuring angles and the laser range finder for measuring distances. Jill and Mark then took turns holding the prism poles and measuring the distances between our instruments and the edge of the hole, while Angie entered the measurements into her laptop. Meanwhile, our photojournalist snapped pictures of our camp, the pit, and us taking various measurements.

  An hour later, we had our initial measurements and headed back to camp, where Mark and Jill helped Bill rustle up a quick dinner of hamburgers, hot dogs, baked beans, and coffee. With no wood to set up an actual campfire, we gathered our chairs around the camp stove and began to eat.

  Kowalski broke the silence by asking the $64,000 question. “So Professor, now that you’ve seen one of the holes up close, what can you tell me about what’s causing them?”

  “That is the question,” I replied, shaking my head in frustration. “I don’t know. Hopefully, I’ll be able to tell you tomorrow once I’ve had a chance to rappel down inside for a closer look.”

  “Well, surely you can tell me something based on all those measurements you made.”

  “Angie, why don’t you give us a summary of our measurements?”

  Putting her plate down on the ground next to her chair, she picked up her laptop and turned it back on. Once she logged in, she brought up our survey application. “As you can see, the hole is nearly circular, measuring between 260 and 276 feet across. The bottom is flat and averages 190 feet deep with the slight differences in depth being due to variations in ground level. The walls of the hole slope an average of 3 degrees inwards from vertical, making the bottom roughly 240 feet across and the walls of the hole – for all practical purposes – straight up and down. That results in a volume of just under 10 million cubic feet.”

  “That’s over 2,000 railway tank cars,” I told Kowalski, translating the volume into terms that the oil company manager would appreciate.

  “That is an awful lot of dirt to go missing,” O’Shannon observed, opening up a notebook so she could take notes. “I understand you are reluctant to speculate on the hole’s origin, Dr. Oswald, but surely you must have a theory.”

  “The problem is that I have three theories, none of which fit all of the facts. The most obvious one is that we’re dealing with a sinkhole, caused by an underground stream that has washed away the dirt leaving an empty hole behind.” I paused, silently contemplating the problems of that theory.

  “That makes sense; I saw a big sinkhole down in Florida once,” Kowalski said. “Granted, it wasn’t as big as this one, but it was still pretty big. So why don’t you think it’s a sinkhole?”

  “The biggest problem is the location. Florida is largely made of limestone covered by sands and silts deposited by ancient beaches. Slightly acidic water percolating through cracks dissolves the limestone, forming extensive caves and underground streams. When the caves get big enough, they collapse causing sinkholes, and the underground streams wash away the loose soil. The North Slope isn’t anything like Florida.”

  I raised my fingers to count off the problems with the sinkhole theory. “First of all, there is very little shallow limestone up here north of the Brooks Range. Without limestone, you don’t get limestone caves. Secondly, there’s the permafrost that Jill mentioned. While we’re standing on hundreds of feet of relatively loose river deposits and windblown silt that could be washed away, the ground here is frozen solid to a depth of at least 1,500 feet and has been that way at least since the last Ice Age. Without an underground stream of liquid water, there’s nothing to wash away the missing contents of the hole. Third, the walls of sinkholes are never vertical. They’re typically larger around just below ground level than they are at the surface, and their bottoms are nearly always very uneven. Finally, I can’t think of a single known phenomenon that could simultaneously create dozens of sinkholes scattered over an area as large as the North Slope.”

  “So if it is not a sinkhole, then what is it?” O’Shannon asked.

  “The second possibility is that it’s the hole left behind when a pingo melted.”

  “I remember you mentioned that word when talking to Mr. Kowalski on the phone,” O’Shannon said “but I am afraid I have forgotten what you said a pingo is.”

  “Jill, why don’t you explain pingos to Miss O’Shannon?” I asked, happy to let my student do the talking to our strangely distracting member of the team.

  “Okay, Dr. Oswald.” Jill paused for a second, undoubtedly trying to remember my lecture on periglacial landforms. “Pingo is an Eskimo word meaning small hill. A pingo is a mound of earth-covered ice that forms in arctic regions over the course of thousands of years. Each winter additional ground water freezes to an existing lens of buried ice. The resulting giant ice lens slowly glows, lifting the overlying soil until it forms a hill. The largest pingos are over 200 feet tall and 2,000 feet in diameter.”

  “Nice summary, Jill. Mark, why don’t you continue by explaining why these holes can’t simply be the remains of pingos that have melted?”

  “Okay. There are several reasons. As Jill said, a pingo is a hill covering a slowly growing, convex lens of ice. The lens gives the pingo its characteristic round shape. The ice lens is also quite shallow because it grows when ground water above the permafrost layer freezes onto the ice lens. While this could explain the hole’s circular shape, it is totally inconsistent with the cylindrical hole’s great depth and vertical walls. Secondly, even with global warming, it would take years, if not decades, to melt all of the ice in a pingo this big, especially when you consider that the soil on top of the ice acts as a layer of insulation, slowing the ice’s melting. Finally, there’s no way that a set of widely distributed, different sized pingos are all going to simultaneously melt over the course of a single night.”

  “Correct, Mark. So we can cross out the simple melting of pingos. How about you, Angie? Given our discussion on methane this morning, what’s our third theory?”

  “Well, maybe the holes started out as pingos. If a pingo’s ice lens happened to block methane rising to the surface from oil reserves through fractures left by earthquakes, the cold and the pressure from the weight of the pingo could have turned the methane gas into a layer of frozen methane hydrate. Then as the pingo melts, the pressure is relieved, releasing the methane like the fizz from a giant bottle of champagne. The resulting explosion blows out the pingo’s ground cover and remaining ice, leaving behind the hole. The small chunks of water ice scattered around the hole quickly melt. As I see it, the main advantage of this theory over melting pingos is that it explains how the holes could suddenly appear, and the record temperatures this summer could partially explain why the holes formed at the same time.”

  “So that’s the answer,” Kowalski said. “Since cracks in the rock would only very rarely rise up directly beneath a pingo, then these holes will also have to be extremely
rare. With luck, all of the pingos that are going to explode have already exploded, and the danger is over.”

  “Not so fast, Kowalski. Honey, now explain why the pingo and methane explosion theory also can’t be right.”

  “Well, we still have the problems of the cylindrical shape of the hole and the fact that such different-sized pingos are not going to simultaneously explode during the same summer, let alone the same night. And look at the ring of lose dirt surrounding the hole. It’s much too neat to have been caused by an explosion. And where is the rest of the dirt that covered the pingo? There should be clumps of it all over the place. Do you see any? Because I sure don’t. No, as much as I’d like to see my work on methane be part of the answer, I just don’t see it.”

  “So, if sinkholes, pingos, and methane explosions aren’t the answer, what is?” Bill asked. “How about meteors? A single swarm of meteors would explain how they all formed at the same time.”

  “Meteorites,” I corrected, unable to help myself.

  “What?”

  “Meteorites, not meteors. They’re only meteors when they are flying through the atmosphere. They become meteorites once they hit the ground.”

  “Okay, meteorites,” our field biologist conceded. He sounded slightly irritated, possibly because I corrected him in front of O’Shannon. “Couldn’t they have been made by meteorites?”

  “No,” I replied. “Meteorite craters have a totally different shape. Besides, meteors big enough to do this would have caused massive explosions. The resulting shock waves would have broken every window in every town and village north of the Brooks Range. And space radar would have picked up any school-bus-sized space rocks as they entered the atmosphere. A series of huge meteor strikes would have been all over the news this morning, and Mr. Kowalski wouldn’t have had to hire us to come investigate.”

  We spent a few hours struggling to come up with better explanations, but each suggestion was shot down almost as soon as it was made. The suggestions became wilder, eventually to the point of silliness.

  “Well, Dr. Oswald, where does that leave us?” O’Shannon asked. “Surely, you do not think that little green men came down and stole the dirt to fuel their spacecraft.”

  I almost started to laugh at her tabloid suggestion, when I saw from Kowalski’s expression that he was seriously considering it.

  “I don’t know what the explanation is,” I answered, “and it’s clear we aren’t going to come up with it sitting around making silly suggestions. What we need is evidence. We need to rappel down into the hole and take samples from the hole’s walls and bottom.”

  The temperature was dropping rapidly as the sun dipped below the northern horizon. I yawned, Angie followed suit, and the yawns traveled around out team like a human wave at a football stadium. “Okay, I’m calling it a night. Tomorrow’s going to be a busy day, and we all are going to need a good night’s sleep.”

  Mark and Jill shared that smile newlyweds give each other, stood, and walked hand-in-hand to their tent, where their sleeping bags no doubt lay zipped together. I couldn’t help but smile myself at the bittersweet memory of how Angie and I used to do the same thing before eventually trading that level of constant intimacy for separate sleeping bags and considerably more uninterrupted sleep. Oh, to be so young and full of passion again. Kowalski, Bill, and O’Shannon went to their separate tents, while I put my arm around Angie as we walked the short distance to the comfortable old tent we’ve shared for so many years of vacations and summer field studies.