Snow Science Against the Avalanche

對抗雪崩的雪科學

On slopes shallow enough to accumulate snow but steep enough for it to be unstable, chaos hides beneath the surface.

在淺到足以積雪,但陡到足以導致不穩定的山坡上,混亂就隱藏在表面之下。

One night earlier this winter, the only road out of Alta, Utah, was closed down. At ski lodges, signs warned guests to stay inside or face fines. Already that season, twenty-two feet of snow had fallen, and, the day before, a storm had dropped thirty-three inches; another foot was predicted by morning. The most dangerous time for avalanches is after a rapid snowfall, and three-quarters of the buildings in Alta are threatened by a known avalanche path. A standard measure for danger on roads, the Avalanche Hazard Index, computes risk according to the size and frequency of avalanches and the number of vehicles that are exposed to them. An A.H.I. of 10 is considered moderate; at 40, the road requires the attention of a full-time avalanche forecaster. State Highway 210, which runs down the mountain to Salt Lake City, if left unprotected, would have an A.H.I. of 1,045.

今年冬天早些時候的一個晚上,離開猶他州阿爾塔市的唯一道路被關閉了。在滑雪旅館,告示牌警告客人留在室內,否則將面臨罰款。那個季節已經下了22英尺的雪,而在前一天,一場風暴就降下了33英寸的雪;預計到早上還會有1英尺。發生雪崩的最危險時刻是在快速降雪之后,阿爾塔有四分之三的建筑受到已知雪崩路徑的威脅。一個衡量道路危險性的標準——雪崩危險指數就是根據雪崩的大小和頻率以及暴露在雪崩中的車輛數量來計算風險。雪崩危險指數為10時被認為是中等水平;達到40時,該道路就需要全職雪崩預報員的關注。而從山上延申到鹽湖城210號州際公路如果不加保護,其雪崩危險指數將達到1045。

Just before 5 a.m., a small group of ski patrollers gathered at a base by the resort’s main lift. Dave Richards, the head of Alta’s avalanche program, sat in the control room. Maps and marked-up aerial photographs hung on the wall next to what looked like a large EKG—that season’s snowfall, wind speeds, and temperature data plotted by hand. Clipboards on hooks were filled with accounts of past avalanches.

就在早上5點之前,一小群滑雪巡邏員聚集在度假村主纜車旁的基地中。阿爾塔雪崩項目的負責人戴夫·理查茲坐在控制室里。墻上掛著地圖和標滿注釋的航空照片,旁邊是一幅巨大的圖表——那一季的降雪量、風速和溫度數據是用手繪制的。掛在鉤子上的剪貼板上則寫滿了過去雪崩的記錄。

Forty and bearded, with tattoos on his arms, Richards has the bearing of a Special Forces soldier. He wore a vest with a radio strapped to it and held a tin of dipping tobacco, spitting occasionally into the garbage can beneath his desk. He obxts when people say that he works in avalanche control; he prefers the term “mitigation.” Sitting nearby was Jude, his English cream golden retriever, named for the patron saint of lost causes.

理查茲四十歲,他滿臉胡須,手臂上有紋身,有一種特種部隊士兵的氣質。他穿著一件背心,上面綁著一臺收音機,拿著一罐浸漬煙草,偶爾向辦公桌下的垃圾桶吐口水。當人們說他從事雪崩控制工作時,他表示反對;他更喜歡用“緩解”一詞。坐在附近的是裘德,他的英國奶油金毛獵犬以迷途者的守護神命名。

Jonathan Morgan, the lead avalanche forecaster for the day, described the snow. He wore a flat-brimmed cap and a hoodie. “Propagation propensity’s a question mark,” he said. “Not a lot of body in the slab. . . . Dry facets, two to three mils,” he continued. “It’s running the whole gamut of crystal types—wasn’t ice, by any means. Rimy, small grains.”

當天的首席雪崩預報員喬納森·摩根描述了這場雪。他戴著一頂平邊帽,穿著一件連帽衫?!傲芽p的擴展傾向還是一個問號”,他說,“板塊中沒有很多雪體……干燥面長達兩到三英里?!彼^續說道:“它包括了所有的晶體類型——但無論如何,它都不是冰。它的外面有一層白霜,呈現為小顆粒狀?!?

At ski resorts like Alta, large avalanches are avoided by setting off smaller ones with bombs. On the walls above the maps were dummy mortar rounds. Above Richards’s desk were binders marked “Old Explosives Inventory.” The idea, Morgan explained, was to “shoot the terrain we can’t get to.”

在阿爾塔這樣的滑雪勝地,大型雪崩是通過用炸彈引爆小型雪崩來加以避免的。在地圖上方的墻上掛著仿制的迫擊炮彈。在理查茲的辦公桌上方有標有“舊爆炸物清單”的夾子。摩根解釋說,這個想法是為了“射擊我們無法到達的地形”。

Richards started considering their targeting plan. The ski resort is cleared from the top down: first by artillery shells, then with hand charges. Before any shots are fired, paths leading to the mountains are closed. Because not all skiers keep to groomed trails—backcountry adventurers seek out remote areas—the Utah Department of Transportation also checks the roadside for tracks. Sometimes it scours the mountainside with infrared cameras before giving the all-clear.

理查茲開始考慮他們的目標定位計劃?;﹫鍪亲陨隙虑謇淼模菏紫仁桥趶?,然后是手榴彈。在發射任何炮彈之前,通往山上的道路都將被關閉。因為不是所有的滑雪者都堅持走梳理過的小路——越野冒險家們會尋找偏遠地區——猶他州交通局也會檢查路邊的痕跡。有時,在批準之前,它還會用紅外線攝像機在山坡上進行搜索。

“So we’ll go fourteen for Baldy?” Richards said. “Doesn’t include a shot seventeen.” Baldy was one of the resort’s mountain faces, at which they planned to fire fourteen shells; seventeen was a spot on its ridgeline.
“Seventeen wouldn’t be the worst idea,” Morgan concurred. “You got a seven in there?”
“When was Baldy shot last?” Richards asked. “Forty inches ago?”
“Yeah, Friday morning.”

“那么,我們將從禿子坡繼續向前十四步?”理查茲說,“不包括17號點?!倍d子坡是度假村的一個山坡,他們計劃向其發射14枚炮彈;17號點是其山脊線上的一個點。
“17號點并不算最糟糕的主意,”摩根同意,“你要向那里發射7枚炮彈?”
“禿子坡最后一次被射擊是什么時候?”理查茲問道:“是積雪厚度40英寸以前?”
“是的,在星期五早上?!?

Richards and Morgan repaired to the mess hall—dark carpet, pool table, a deer head on the wall—for breakfast. At five-thirty, the ski lift opened. As Richards walked out the door, Liz Rocco, another ski patroller, mentioned that she had prepared some of the hand charges they would be using that morning. “And I will light them, and throw them into the darkness,” Richards said.

理查茲和摩根回到了食堂——這里有黑暗的地毯、臺球桌、墻上的鹿頭——吃早餐。五點半的時候,滑雪纜車開動了。當理查茲走出門時,另一位滑雪巡邏員麗茲·羅科提到,她已經準備好了一些他們那天早上要用的手榴彈?!拔覍Ⅻc燃它們,并把它們扔進黑暗中,”理查茲說。

We rode the lift up in the moonlight. Snow was falling on the fir trees. Richards spent his childhood at Alta: his father was a ski patroller for thirty-three years, and his mother, who later became a university administrator, worked the front desk at the Rustler Lodge. Richards started his career as a professional skier, then worked as a heli-skiing guide, before joining the patrol full time. “The thing that makes it for me is the snow,” he said. “Working with a natural material that can be—” He paused. “It’s light and fluffy and soft and downy, and it’s everybody’s favorite thing in the world. It’s also one of the most destructive forces in nature. Under the right conditions, that soft, wonderful little snowflake can tear forests out of the ground, throw cars through the air, flatten buildings. And you get to watch that.”

我們在月光下乘坐電梯上去。雪落在冷杉樹上。理查茲在阿爾塔度過了他的童年:他的父親在滑雪場當了33年的巡邏員,他的母親后來成為一名大學管理人員,在拉斯特爾旅館的前臺工作。理查茲以職業滑雪者的身份開始了他的職業生涯,然后擔任直升機滑雪向導,最后全職加入巡邏隊。他說:“對我來說,最重要的事情是雪?!薄芭c一種天然材料一起工作,可以…… ”他停頓了一下,“它輕盈、蓬松、柔軟、有絨毛,它是世界上所有人最喜歡的東西。它也是自然界中最具破壞性的力量之一。在適當的條件下,這種柔軟、美妙的小雪花可以把森林從地面上撕下來,把汽車拋向空中,把建筑物壓平。而你可以看到這些?!?

At the top of the lift, we started hiking. A voice crackled over the radio. “Copy,” Richards said. “Just give me a holler when you pull the trigger.” A moment later, the radio crackled again; Richards ducked and covered his head, and an explosion went off somewhere nearby. We resumed hiking. After a few minutes, we arrived at a two-story shed. A garage door opened onto a pair of hundred-and-five-millimetre howitzer cannons, of Second World War vintage, installed on semicircular tracks. The gun barrels were pointed at the mountaintops. A crew was loading bags of gunpowder into the undersides of artillery shells—enormous bullets, six inches wide and two and a half feet long. Richards wrapped a rag around a large stick and jammed it into a gun barrel, to clean it. “One Sunday morning,” he began singing to himself. “As I went walking . . .”

在電梯的頂部,我們開始徒步旅行。一個聲音在無線電中噼里啪啦地響起?!笆盏?,”理查茲說道,“當你扣動扳機時,吱一聲?!?一會兒,無線電又響了起來;理查茲躲了起來,捂住了頭,附近某個地方發生了爆炸。我們重新開始了徒步旅行。幾分鐘后,我們來到了一個兩層樓的棚子。一扇車庫的門打開了,里面有一對一百零五毫米的榴彈炮,它們是第二次世界大戰的產物,安裝在半圓形的軌道上。炮管對準了山頂。一名工作人員正在將一袋袋火藥裝入炮彈的底部——巨大的炮彈寬六英寸,長兩英尺半。理查茲將一塊抹布纏在一根大棍子上,塞進一根炮管來清潔它?!耙粋€星期天的早晨,”他開始對自己唱歌,“當我走在路上……”
原創翻譯:龍騰網 http://www.codygalaherlaw.com 轉載請注明出處


The patrollers donned foam earplugs and large over-ear headphones; Richards and his co-gunner walked around one of the weapons, checking locks and bolts. They turned a crank, and the barrel swung toward its first target.
“Zero, zero, two, seven,” Richards yelled—the elevation and the deflection. Two other patrollers confirmed the co?rdinates. “Ready to fire,” Richards said. “Fire!”
He pulled hard on a chain. The muzzle flashed, and a plume of acrid smoke filled the air. There was a high-pitched ringing.

巡邏人員戴上了泡沫耳塞和大型耳罩式耳機;理查茲和他的副炮手繞著其中一件武器走了一圈,檢查鎖和螺栓。他們轉動一個曲柄,炮管向第一個目標擺動。
“零,零,二,七,”理查茲大喊——這是仰角和偏轉度。另外兩名巡邏員確認了這一坐標?!皽蕚溟_火,”理查茲喊道:“開火!”
他用力拉動一條鐵鏈。炮口一閃,一縷刺鼻的煙霧彌漫在空氣中,發出了一陣高亢的響聲。

It wasn’t possible to see the mountain, but Richards listened for impact and, a few seconds later, yelled, “Report!” Outside, while the barrage continued, a patroller named Kyle took a small cast-booster explosive out of his pack: it resembled two cans of beans wired together with licorice, the cartoon version of a bomb. He pulled the fuse and tossed it underhand over the cliffside. “That didn’t go where I wanted,” he said. Ninety seconds later, it exploded into a black-and-white cloud of snow dust.

那座山是無法看到的,但理查茲聽著了中彈聲,幾秒鐘后,他大喊:“報告!”在外面,當炮擊繼續進行時,一個名叫凱爾的巡邏員從他的背包里拿出了一個小型助推炸藥:它就像兩個豆子罐頭用甘草連在一起,是一種卡通版的炸彈。他拉開導火線,暗中把它扔到了懸崖邊上。他說:“這不是我想要的結果”。90秒后,它爆炸了,變成一團黑白相間的雪塵。

Afterward, the cleaning and stowing of the guns began. When everything was done, it was nearly nine o’clock. Richards prepared to ski back toward the base. During the night, the resort had sent an alx to Alta skiers, telling them to expect between nine and fourteen inches of new snow—some of the best skiing of the season. On the way down, the sun shone on fresh powder reaching up to Richards’s waist. Small cracks shot out from his ski tips as he descended. Piles of snow slid downslope. He paused and, turning his ski pole upside down, began using it as a probe. The pole slid easily into the first foot of snow. Feeling resistance, he pushed harder—and broke through into a hollow. After the snow settled and drifted, there could be avalanches.

之后,他們開始清洗和收放槍支。當一切完成后,已近九點。理查茲準備滑回基地。夜里,度假村向阿爾塔的滑雪者發出警報,告訴他們預計會有9至14英寸的新降雪——這可以算是本季最好的滑雪機會之一了。在下山的路上,陽光照耀著新鮮的雪粉,它直達理查茲的腰部。當他下山時,小裂縫從他的滑雪尖上射出。一堆堆的雪從斜坡上滑落下來。他停了下來,把他的滑雪桿倒過來,開始把它當作一個探測器?;U輕松地插入第一英尺的雪地。感覺到阻力后,他更加用力——沖進了一個空洞。在雪沉淀和漂移之后,可能會出現雪崩。
原創翻譯:龍騰網 http://www.codygalaherlaw.com 轉載請注明出處


The project of avalanche control in the Alps goes back at least to 1397, in Andermatt, Switzerland, with a law that prohibited logging. Swiss peasants had moved farther into the mountains. Their new farmhouses sat in avalanche paths. It was soon discovered that old-growth trees anchored the snow and kept slides from gathering mass. During the eighteen-seventies, Johann Coaz, the head of the Swiss Forest Service, made records of historical avalanches. He drew up maps of potential disaster zones and designed walls to protect vulnerable settlements; the stones used to build them were hauled up the mountainsides by hundreds of men.

阿爾卑斯山的雪崩控制項目至少可以追溯到1397年,在瑞士的安德馬特,有一項禁止伐木的法律。瑞士農民已經搬到了更遠的山里。他們的新農舍坐落在雪崩的道路上。人們很快發現,古老的樹木可以固定住雪,使滑坡不至于聚集成一團。十八世紀七十年代,瑞士林業局局長約翰·科茲對歷史上的雪崩進行了記錄。他繪制了潛在災害區的地圖,并設計了保護脆弱居民點的墻壁;用于建造墻壁的石頭由數百人拖到山坡上。

Around the same time, prospectors in the western United States began finding silver ore high in the mountains. At Alta, which began as a major silver camp, miners logged the alpine forests for firewood and to reinforce their tunnels. According to legend, the avalanche danger grew so high that women weren’t allowed to live there in winter. Alta was abandoned in 1927, when the price of silver plummeted, but, in the nineteen-thirties, European-style ski resorts spread across the American West. The first mechanical lift appeared in Alta in 1939.

大約在同一時間,美國西部的勘探者開始在高山上發現銀礦。在阿爾塔,最初建造的一個大型的銀礦營地,礦工們砍伐高山森林作為木柴并加固他們的隧道。據傳說,雪崩的危險性越來越高,以至于婦女在冬天不被允許住在那里。阿爾塔在1927年銀價暴跌時遭到了遺棄,但在1930年代,歐洲風格的滑雪勝地遍布美國西部。1939年,阿爾塔出現了第一條機械索道。

After the Second World War, some veterans of the U.S. 10th Mountain Division, who had trained for alpine combat, found themselves responsible for snow safety at the resorts. In 1945, Montgomery Atwater, a freelance writer who had fought with the 10th, heard about a snow-ranger job at Alta and applied on a whim. “That Alta was ideally conceived by nature to become the first avalanche research center on this continent and that I was there to take the plunge were mere coincidences,” he later wrote, in “The Avalanche Hunters,” from 1968.

第二次世界大戰后,美國第十山地師的一些退伍軍人——他們曾接受過高山作戰的訓練——開始負責度假區的雪地安全。1945年,曾在第10師戰斗過的自由作家蒙哥馬利·阿特沃特聽說阿爾塔有一份雪地巡視員的工作,一時興起就去申請了。他后來在1968年的《雪崩獵人》中寫道:“阿爾塔被大自然完美地構想為這個大陸上的第一個雪崩研究中心,而我在那里決定冒險一試,這只是巧合而已?!?

Alta lies at the center of three storm tracks, from Canada, the Gulf of Alaska, and the Pacific. Storm systems accumulate moisture in the Salt Lake and, as they rise into the mountains, release about forty-five feet of snow each winter. Atwater learned that although snow always begins the same way—with a water droplet condensing around a dust mote or pollen to form a six-pointed snowflake—it can take innumerable forms later. Snow acts like both a solid and a liquid: it flows—even a blanket of snow on a hillside is slowly creeping—while maintaining its structure. Scientists consider it to be “warm,” because it is always close to its melting point. This is why, before you make your first snowball of the day, it is hard to know how well it will pack: you are working with a material that is about to change state. It’s like building a bridge with red-hot steel.

阿爾塔位于三個風暴路徑的中心,它們分別來自加拿大、阿拉斯加灣和太平洋。風暴系統在鹽湖中積累水分,當它們上升到山區時,每年冬天會釋放出大約45英尺的雪。阿特沃特了解到,盡管雪總是以同樣的方式開始——水滴在塵?;蚧ǚ壑車Y,形成六角形的雪花——但之后卻可以采取無數的形式。雪的行為既像固體又像液體:它在流動——甚至山坡上的一片雪毯也在緩慢地蠕動——同時保持其結構??茖W家認為它是“溫暖的”,因為它總是接近其熔點。這就是為什么在你做今天的第一個雪球之前,你很難知道它的包裹效果如何:你正在處理一種即將改變狀態的材料。這就如同用燒紅的鋼建造一座橋。

We think of the snow on a mountain as a solid mass. In reality, it is a layer cake created by serial snowfalls, each layer distinctive and changeable. “The snow cover is never in a state of repose,” Atwater wrote. “It is continually being pushed, pulled, pressed, bent, warmed, chilled, ventilated, churned.” The topmost layer might be evaporating into the night air; at the same time, radiant heat from the ground, or from nearby trees, could be melting the lowest layer. When the temperature differences between the layers are small, snow tends to sinter, or coalesce: the crystals knock off one another’s arms, becoming rounded grains that fuse into a strong, dense snowpack. When the differences are larger—say, between the pack and the ground—snow vaporizes upward and refreezes, creating hollow, cup-shaped crystals. The result is brittle, spiky snow, called depth hoar. (In ice cream, a similar process creates freezer burn.)

我們認為山上的雪是一個固體塊。實際上,它是一個由連續降雪形成的層狀蛋糕,每一層都是獨特的、可改變的。阿特沃特寫道:“雪層從未處于靜止狀態,它不斷地被推、被拉、被壓、被彎曲、被加熱、被冷卻、被通風、被攪動?!弊钌厦娴囊粚涌赡苷谡舭l到夜晚的空氣中;同時,來自地面或附近樹木的輻射熱可能正在融化最底下的一層。當各層之間的溫差較小時,雪往往會熔結,或凝聚在一起:晶體相互撞擊,成為圓形的顆粒,融合成一個堅固、密集的雪堆。當溫差較大時,例如,在雪塊和地面之間,雪向上蒸發并重新凍結,形成空心的杯狀晶體。其結果是脆性的、帶刺的雪,被稱為深度囤積物。(在冰激凌中,一個類似的過程產生了冰柜凍燒)。

Neither settled snow nor weak hoar is dangerous in itself. The problem arises when a dense layer lies atop a weak layer to which it is poorly bonded. Depth hoar is “the eeriest stuff on any mountain,” Atwater wrote; it grows unseen, rotting the snow until it is weak and potted. It is strong in compression but weak in shear. Like a row of champagne glasses slowly loaded with bricks, it can hold a surprising amount of weight until, with the slightest shove, the structure falls apart, creating a slab avalanche.

無論是穩定的雪還是脆弱的白霜,其本身都不危險。當一個密集的雪層位于一個脆弱的雪層之上時,問題就出現了,因為兩者之間結合得很差。深層積雪是“所有山巒上最可怕的東西”,阿特沃特寫道;它在不為人知的情況下生長,破壞雪,直到它變得脆弱和腐爛。它在壓縮方面韌性強大,但在剪切方面卻很弱。就像一排香檳酒杯慢慢地裝上磚頭一樣,它可以承受驚人的重量,直到在最輕微的推力下,結構分崩離析,形成板狀雪崩。

The word “avalanche” is too graceful for the phenomenon it describes. On slopes shallow enough to accumulate snow but steep enough for it to be unstable—the sweet spot is said to be thirty-nine degrees—the layers will separate, and the slab will crack and slide. Churning violently, the snow reaches eighty miles per hour within a few seconds. A skier who avoids colliding with trees and rocks is likely to be pulled under, then pinned in place by thousands of pounds of snow that harden like concrete. Very few people can dig themselves out; most can’t even move their fingers. Within minutes, an ice mask forms around your face. You asphyxiate on your own exhaled carbon dioxide.

“雪崩”這個詞對于它所描述的現象來說太過優雅了。積雪在足夠淺的斜坡上,但它又足夠陡峭,使雪不穩定——據說最有效的坡度是39度——雪層會分離,板塊會開裂和滑動。在激烈的攪動下,雪在幾秒鐘內達到每小時80英里的速度。一個避免與樹木和巖石相撞的滑雪者很可能被它趕上,然后被數千磅像混凝土一樣變硬的雪釘在原地。很少有人能把自己挖出來;大多數人甚至不能移動他們的手指。在幾分鐘內,你的臉就會形成一個冰罩。你會因為自己呼出的二氧化碳窒息而死。

At a test site in the mountains, Swiss scientists have set off avalanches powerful enough to destroy their equipment. Photograph by Yann Gross

在山區的一個試驗場,瑞士科學家引發了足以摧毀其設備的雪崩。
原創翻譯:龍騰網 http://www.codygalaherlaw.com 轉載請注明出處


In his book “Staying Alive in Avalanche Terrain,” from 2008, Bruce Tremper, the former director of Utah’s Avalanche Center, offers a taxonomy of avalanches. In slab avalanches—the most dangerous kind—an entire layer releases at once. In storm slabs or wind slabs, the releasing layer falls from above; in wet slabs, a layer lower down is weakened by water; in a persistent slab, it was weak to begin with. A soft slab, composed of powdery snow, tends to break where you stand; a hard slab breaks above you, which is more perilous. Non-slab avalanches are said to be “loose.” In a dry loose avalanche, powder releases in disconnected sloughs. Wet loose avalanches—portended by “pinwheels,” small snowballs that leave streaks as they roll—are slower but stickier, and more likely to bury you if you get caught. Mixed avalanches, which start dry and get wet lower on the slope, have become increasingly common. So have glide avalanches, caused by meltwater seeping in below the snowpack.

猶他州雪崩中心前主任布魯斯·特倫普在其2008年出版的《在雪崩地帶生存》一書中提供了雪崩的分類法。在板狀雪崩(最危險的一種雪崩)中,整個雪崩層一次性被釋放出來。在風暴雪崩或風雪崩中,釋放層從上面落下;在濕雪崩中,較低的一層雪被水削弱;在持續的雪崩中,它一開始就很脆弱。由粉狀雪組成的軟雪層往往在你站立的地方斷裂;硬雪層在你上方斷裂,這就更危險了。非板狀雪崩被說成是“松散的”雪崩。在干燥的松散雪崩中,粉末以斷開的槽狀釋放出來。濕的松散雪崩——其預兆是“針輪”,即滾動時留下條紋的小雪球構成——速度較慢,但更粘稠,如果你被卷入,它更有可能將你埋葬?;旌涎┍馈_始時是干的,在坡度較低的地方變濕——已經變得越來越普遍?;瑒友┍酪彩侨绱?,它是由雪堆下面的融水滲入造成的。

Students of tsunamis or volcanoes must wait for nature to deliver their disasters, but an avalanche can be provoked. In the nineteen-fifties, Atwater used a technique now called “ski-cutting.” Two patrollers descended dangerous slopes; while one looked on, ready to stage a rescue, the other skied to a safe point on the far side, picking up enough speed to try and ride through any avalanches he might start. In theory, the slopes that slid were safer because of it; the ones that didn’t were deemed stable enough for everyone else.

研究海嘯或火山的學生必須等待大自然給他們帶來災難,但雪崩是可以被引發的。在1950年,阿特沃特使用了一種現在稱為“滑雪切割”的技術。兩名巡邏員從危險的山坡上下來;當一名巡邏員看著,準備進行救援時,另一名巡邏員則滑到遠處的一個安全點,提高足夠的速度,試圖穿越他可能引發的任何雪崩。從理論上講,滑落的斜坡因此更安全;沒有滑落的斜坡對其他人來說也被認為足夠穩定。

It wasn’t practical to ski-cut every hill. Knowing that the Swiss used bombs to combat avalanches, Atwater tapped the Forest Service’s wartime supply of tetrytol, the high-powered explosive; he asked his supervisor whether he could have some artillery, for distant targets. National Guardsmen arrived with a First World War-era French 75. (“What would avalanche research be without war surplus?” he later wrote.) For mid-range targets, too close for artillery but too distant for hiking or skiing, Atwater tried rifle grenades, bazookas, bombs dropped from helicopters, and an air-to-air rocket known as the Mighty Mouse. These methods were too costly, or unsuited to the snow; in the end, a modified ball machine, of the sort used for batting practice, was the most reliable delivery mechanism. Richards’s team still uses Atwater’s “Avalauncher” to shoot about thirty rounds each morning.

對每個山頭進行滑雪切割并不切合實際。阿特沃特知道瑞士人用炸彈來對付雪崩,于是他動用了林務局戰時供應的“三氧化二氮”,即高能炸藥;他詢問其上司,他是否可以得到一些炮彈,用于轟擊遠處的目標。國民警衛隊的人帶著第一次世界大戰時期的法國75型大炮來到了這里。(他后來寫道:“如果沒有戰爭遺留物,雪崩研究會是什么樣子?”)中距離目標對火炮來說太近,但對徒步旅行或滑雪來說又太遠,阿特沃特嘗試了槍榴彈、火箭筒、從直升機上投下的炸彈,以及一種被稱為“大老鼠”的空對空火箭。這些方法成本太高,或者不適合在雪地上使用;最后,一個改良的發球機,即用于擊球練習的那種機器,成為了最可靠的投擲器械。理查茲的團隊仍然使用阿特沃特的“雪崩機”,每天早上發射大約30發子彈。

Atwater worked with Ed LaChapelle, who had done a stint at the Swiss Avalanche Institute, to create a “snow study plot”—a clearing where they could measure snowfall and take samples of the snowpack at regular intervals. They tracked the snow’s rate of accumulation and weight in water, discovering that weight mattered far more than depth: when placed atop a layer of hoar, a foot of fluffy powder was less dangerous than three inches of dense slush. Wind, they learned, could deposit many feet in just a few hours; pillows of windblown snow looked tranquil but were deadly. Studying how snow settled, Atwater wrote, “We saw things going on within that placid-appearing mass which no man had seen before—or even suspected.” He concluded, “There are apparently random plastic flows and currents within the snow cover whose causes and effects were unknown, and still are.”

阿特沃特與曾在瑞士雪崩研究所工作過的埃德·拉夏貝爾合作,創建了一個“雪地研究區”——一個他們可以測量降雪量并定期采集雪堆樣本的空地。他們跟蹤了雪的積累速度和水的重量,發現重量比深度重要得多:當放置在一層白霜上時,一英尺的蓬松粉末比三英寸的稠密泥漿更危險。他們了解到,風可以在短短幾個小時內存積許多英尺的雪;被風吹起的雪枕看起來很平靜,但卻是致命的。阿特沃特在研究雪是如何沉積的時候寫道:“我們看到在這塊看似平靜的土地上發生的事情,以前沒有人看到過,甚至沒有人懷疑過?!彼偨Y說:“在雪層中顯然存在著隨機的塑性形變和流動,其原因和影響不為人知,現在也是如此?!?

In 1805, the Irish hydrographer Sir Francis Beaufort developed a scale for measuring wind speed at sea by observation. Later, it was adapted for use on land. In his book “Defining the Wind,” from 2004, Scott Huler argues that the descxtions accompanying the scale, which were written anonymously, should count as literature. At Beaufort 0, the wind is “calm; smoke rises vertically.” At Beaufort 3, a gentle breeze, one sees “leaves and small twigs in constant motion.” At Beaufort 5, a fresh breeze, “small trees in leaf begin to sway; crested wavelets form on inland waters.” The poetic descxtions connect subjective impressions to obxtive reality. A near-gale—a Beaufort 7—is defined by “whole trees in motion; inconvenience in walking against wind.” See and feel those things, and you know that the wind is between thirty-two and thirty-eight miles per hour.

1805年,愛爾蘭水文學家弗朗西斯·博福特爵士開發了一個通過觀察測量海上風速的標尺。后來,它被調整為在陸地上使用。斯科特·胡勒在他2004年出版的《風的定義》一書中認為,該標尺附帶的由無名氏創作的描述應該算作文學作品。在蒲福0級,風是“平靜的;煙霧垂直升起”。在蒲福3級,微風柔和,人們看到“樹葉和小樹枝在不斷運動”。在蒲福5級,清新的微風,“落葉的小樹開始搖擺;內陸水域形成波浪”。詩意的描述將主觀印象與客觀現實聯系起來。疾風——蒲福7級——則是由“整棵樹在運動;逆風行走不便”所定義??吹胶透杏X到這些東西,你就知道風速在每小時三十二至三十八英里之間。
原創翻譯:龍騰網 http://www.codygalaherlaw.com 轉載請注明出處


Atwater devised an analogous guide to snow. His language is evocative, but there’s less authority in the descxtions. “Unstable damp snow is tacky,” he wrote. “It slithers out from underfoot and rolls away in balls or slips blanketwise. . . . Well settled snow has good flotation and makes a clean, sharp track.” Snow is less forthcoming than the wind. Its chaos hides beneath the surface.

阿特沃特為雪設計了一套類似的指南。他的語言是令人回味的,但描述中的權威性較低。他寫道:“不穩定的濕雪是粘稠的,它從腳下溜走,滾成球狀或滑成毯狀……穩定性好的雪具有良好的浮力,能形成干凈、銳利的軌跡?!毖]有風那么容易吐露訊息。它的混亂隱藏在表面之下。

One crisp, bright morning in February, I walked along a brook just outside the center of Davos, toward the headquarters of the Swiss Institute for Snow and Avalanche Research. In Davos, the train from the valley potters up through wooded hills, picking up locals in ski boots; the S.L.F., as the institute is now known, occupies a squat building a few minutes from the train station. A small exhibit in the lobby explains the history of snow and avalanches in Switzerland.

二月的一個清晨,我沿著達沃斯中心外的一條小溪走去,向瑞士雪崩研究所的總部走去。在達沃斯,來自山谷的火車穿過林立的山丘,接載穿著滑雪靴的當地人;雪崩研究所在距離火車站幾分鐘的地方占據了一棟簡陋的建筑。大廳里的一個小展覽解釋了瑞士的雪和雪崩的歷史。

In 1951, while Atwater was experimenting with explosives, Switzerland experienced the worst avalanche season in its recorded history. Ten feet of snow fell in ten days. About a hundred people were killed; villages that had survived avalanches for centuries were destroyed. The S.L.F., which was founded in 1942, suddenly became an institution of national import.

1951年,當阿特沃特正在進行炸藥實驗時,瑞士經歷了有史以來最嚴重的雪崩季節。十天內下了十英尺的雪。大約一百人喪生;在雪崩中幸存了幾個世紀的村莊被摧毀了。成立于1942年的雪崩研究所突然成為一個具有國家意義的機構。

Henning L?we, the forty-six-year-old head of the institute’s Cold Lab, wears an earring in his right ear; before taking up the study of snow, he received a Ph.D. in theoretical condensed-matter physics. Dressed in jeans, black Nikes, and a worn fleece shirt, he led me inside the lab, where computers sat beside refrigerated rooms with three-inch-thick steel doors. The lab’s goal, he explained, was to find out what the wetness or heaviness or hoariness of snow really meant, on the level of its crystals. “We are connecting physical properties of snow to structure,” L?we said. He picked up a palm-size cube that looked elaborately hollowed out, like a plaster mold of a termite’s nest. A twenty-millimetre-wide sample of snow had been taken from the crown of an avalanche—the pit that’s left when a slab releases—scanned with X-rays, and then 3-D-printed in plastic, at high magnification: the layer cake, under a microscope. The weak, bottom layer was composed of what looked like large popcorn kernels. The top layer, which had settled, was a tight tangle, like instant ramen. “You start to shear this thing”—L?we made a chopping motion where the two layers met—“it’s ninety-nine per cent sure that this will break there.”

亨寧·洛維,這位46歲的研究所寒冷實驗室的負責人右耳戴著一個耳環;在從事雪的研究之前,他獲得了理論凝聚物質物理學的博士學位。他穿著牛仔褲、黑色耐克鞋和一件破舊的羊毛衫,把我領進實驗室,實驗室里的電腦就放在有三英寸厚的鋼門的冷藏室旁邊。他解釋說,實驗室的目標是在其晶體層面上找出雪的濕潤、沉重或粗糙的真正含義?!拔覀冋趯⒀┑奈锢硖匦耘c結構聯系起來”,洛維說道。他拿起一個手掌大小的立方體,看起來已經被精心挖空了,就像白蟻巢的石膏模型。一個20毫米寬的雪樣被從雪崩的頂部取下——用X射線掃描雪層時留下的坑,然后用塑料在高倍鏡下進行三維打?。哼@是顯微鏡下的夾心蛋糕。脆弱的底層是由看起來像大爆米花核的東西組成的。已經沉淀下來的頂層是一個緊密的雪團,就像即食拉面?!叭绻覀冮_始剪切這個東西”——洛維在兩個雪層相接的地方做了一個切割的動作——“它就有百分之九十九的把握會在那里破裂開來”。

Snow science has come a long way since Atwater’s experiments at Alta. The basic process by which newly fallen snow crystals sinter into a cohesive slab can now be seen in slow motion: it resembles the way ice cubes in an empty glass fuse together. The process of recrystallization—the re-separating of the cubes—was more mysterious. L?we opened a closet, and pulled a cylinder from a shelf marked “Snowbreeder 3.” The device allows scientists to observe a snow sample while applying varying degrees of heat and pressure. At his computer, L?we played a time-lapse video of “snow metamorphism” in the Snowbreeder. “In the beginning, it’s typical snow, it’s round-grained snow, the crystals are small,” he said. Then heat was applied from below. The lower crystals began evaporating their moisture to the crystals above, which used it to grow downward. “We see that, here, a facet’s growing. There, a facet’s growing,” he said, pointing. This was hoar—the snow becoming spiky, brittle, weak. “Seeing something is always the beginning of understanding,” he said.

自阿特沃特在阿爾塔的實驗以來,雪的科學已經有了長足的進步?,F在可以在慢動作中看到新落下的雪的晶體融結成粘性板塊的基本過程:它類似于空杯子中的冰塊融合在一起的方式。再結晶的過程——冰塊的重新分離——更加神秘。洛維打開一個壁櫥,從一個標有“Snowbreeder 3”的架子上拿出一個圓筒。該設備允許科學家在施加不同程度的熱量和壓力的同時觀察雪樣。在他的電腦前,洛維在Snowbreeder中播放了一段“雪的變質”的延時視頻。他說:“一開始,它是典型的雪,它是圓形顆粒的雪,晶體很小?!比缓髲南旅媸┘訜崃?。下面的晶體開始向上面的晶體蒸發它們的水分,上面的晶體利用它向下生長?!拔覀兛吹?,這里,一個切面正在生長”,他指著那里說道。這是白霜——雪變得尖尖的、脆脆的、非常脆弱。他說:“所見總是理解的開始。

The scientific study of snow layers has refined our understanding of avalanches. In 2008, a study published in Science by a group of Scottish and German materials researchers modelled how, when one part of a heavy layer of snow collapses onto a weak layer, it can produce a wave. Their model explained a curious observation from the field: skiers occasionally trigger deadly avalanches above or below them, even when standing on flat slopes. The weak layer, it turns out, behaves like the coils in a mattress: apply force in one place, and it spreads all over the bed. The concept is now a cornerstone of avalanche-safety education, where it is known simply as “remote triggering.”

對雪層的科學研究已經完善了我們對雪崩的理解。2008年,一組蘇格蘭和德國的材料研究人員在《科學》雜志上發表了一項研究,模擬了當厚重的雪層的一部分坍塌到一個薄弱的雪層上時,如何產生波浪。他們的模型解釋了現場的一個奇怪的觀察結果:滑雪者偶爾會在他們上方或下方引發致命的雪崩,即使是站在平坦的斜坡上。事實證明,薄弱層的行為就像床墊中的線圈:在一個地方施力,它就會散布到整個床上。這個概念現在是雪崩安全教育的一個基石,在那里它被簡單地稱為“遠程觸發”。

Snow research also has applications beyond avalanches. Spinning his keys around a finger, L?we led me through the cold rooms. In one, a humidifier generated tiny clouds of perfect, lab-grown powder; in another, snow from the Arctic, Finland, and Iceland had been carefully preserved. Scientists are studying how snow’s crystal structure determines its color, or “albedo,” which, in turn, affects its ability to act like a giant mirror and mitigate global warming.

雪地研究也有雪崩以外的應用。洛維用手指旋轉著他的鑰匙,帶我參觀了這些寒冷的房間。在一個房間里,一個加濕器產生了完美的、實驗室培育的粉末的小云團;在另一個房間里,來自北極、芬蘭和冰島的雪被精心保存起來??茖W家們正在研究雪的晶體結構如何決定其顏色,或“反照率”,這反過來又影響其如同一面巨大的鏡子和緩解全球變暖的能力。

In an upstairs office with mountain views, Perry Bartelt, a gray-haired research engineer, works on Rapid Mass Movement Simulation, or ramms—software for simulating avalanches. The week before, an avalanche in Turkey had killed half a dozen people; dozens more died during the rescue, when the mountain avalanched a second time. Turkish researchers had rushed data from both slides to Bartelt. ramms calculated that the first avalanche had hit the bottom of the slope with five times the force needed to knock down a building. Its core had the density of wood.

在樓上一間可以看到山景的辦公室里,白發蒼蒼的研究工程師佩里·巴特爾正在進行快速大規模運動模擬,即ramms——這是一款模擬雪崩的軟件。一周前,土耳其的一場雪崩造成6人死亡;在救援過程中,山體第二次雪崩,又有數十人死亡。土耳其研究人員急忙將兩次雪崩的數據交給了巴特爾??焖俅笠幠_\動模擬軟件計算出,第一次雪崩撞擊坡底的力量是推倒一座建筑所需力量的五倍。它的核心部分具有木材的密度。
原創翻譯:龍騰網 http://www.codygalaherlaw.com 轉載請注明出處


Using a terrain map, ramms predicts the path and the power of an avalanche. Its central innovation is its ability to treat an avalanche as a “granular shear flow,” using statistics to average out the activity of millions of interacting grains. Imagine a box of cereal, full of flakes and marshmallows; now pour it out. Some bits will fly straight, carried by their own momentum. Others will catch on the surface they’re sliding down. Many flakes will shake against one another, breaking up and settling below the intact marshmallows. (In granular flows, small things sink beneath bigger ones.) ramms seeks to predict the outcome of this churn.

使用地形圖,快速大規模運動模擬軟件預測了雪崩的路徑和力量。它的核心創新是它能夠將雪崩視為 "顆粒剪切流",利用統計學來平均化數百萬相互作用的雪粒的運動。想象一下一盒麥片,里面裝滿了片狀物和棉花糖;現在把它倒出來。一些碎片會直接飛起來,被它們自己的動力帶著。其他的會被它們滑下去的表面抓住。許多片狀物會相互搖晃,碎裂并沉淀在完整的棉花糖下面。(在顆粒狀的流動中,小東西會在大東西下面沉下去。)快速大規模運動模擬軟件試圖預測這種攪動的結果。

The software was validated on historical avalanches—especially on data about whether trees had been knocked down, and, if so, how old they were. “Trees are wonderful mechanical sensors,” Bartelt said. If an avalanche takes down a seventy-year-old stand of trees, you know that the avalanche has a return period of at least seventy years. Fine-tuning the model would require more precise data, which are hard to come by. Gathering this information would require taking readings inside, or under, an avalanche.

該軟件在歷史雪崩中得到了驗證——特別是關于樹木是否被撞倒的數據,如果是的話,它們的年齡有多大。巴特爾說道:“樹木是奇妙的機械傳感器。如果雪崩撞倒了一棵有七十年樹齡的樹木,你就知道雪崩的回歸期至少有七十年。對模型進行微調將需要更精確的數據,而這些數據很難得到。收集這些信息將需要在雪崩內部或下方進行讀數。

For this purpose, the S.L.F. maintains an avalanche test site in the Vallée de la Sionne—a steep, mountainous area about two hundred miles from Davos. Hearing the phrase “test site,” one might imagine a bunny slope. Actually, it is an enormous mountain, improbably reserved for science.

為此,雪崩研究所在雄恩峽谷維持著一個雪崩試驗場——這是一片離達沃斯約200英里的陡峭山區。聽到 “試驗場“這個短語,人們可能會想到一塊平緩滑雪坡。但實際上,它是一座不可能是為科學保留的巨大的山。

The site’s chief scientist is Betty Sovilla, a hydraulics engineer. When we met at S.L.F., she was wearing red-frxd glasses, a black cardigan, jeans, and red boots. “ramms is a very simplified model,” she said. The goal of the test site was to develop a more realistic version, by correlating detailed measurements of the snow cover with the avalanches it created. She was particularly interested in glide avalanches: there were more of them every year, but they were elusive. “You cannot predict when they are released,” she said. “This is really the avalanche of the future.”

該基地的首席科學家是貝蒂·索維拉,她是一位水力學工程師。當我們在雪崩研究所見面時,她戴著紅框眼鏡,穿著黑色開衫、牛仔褲和紅色靴子?!翱焖俅笠幠_\動模擬軟件是一個非常簡化的模型,”她說。試驗場的目標是開發一個更真實的版本,通過對雪層的詳細測量與它所產生的雪崩相關聯。她對滑動雪崩特別感興趣:每年都有更多的滑動雪崩,但它們難以捉摸。她說:“你無法預測它們何時被釋放。這確實是未來的雪崩?!?

One morning, Pierre Huguenin, a forty-nine-year-old mountaineer and snow scientist, drove me to the site in a white Mitsubishi Pajero. “You see the flakes. You see the crystals,” he said, gesturing out the window. There had been a storm the previous night. He stopped the car where the road ended, and we changed into snowshoes.

一天早上,四十九歲的登山家和雪地科學家皮埃爾·胡戈寧開著一輛白色的三菱帕杰羅載我到現場?!澳憧吹搅搜┗?。你看到了晶體,”他說著,指向了窗外。前一天晚上有一場暴風雨。他把車停在路的盡頭,我們換上了雪鞋。

Outside, there was about a foot of pristine powder. I stooped and ran my hand through it. Bone-dry, it was the pure bright white of confectioner’s sugar, with the texture of sea salt. Huguenin pulled out his phone. The avalanche forecast for the area had us covered in orange. “We are in the third degree,” he said—the risk category in which the most avalanche deaths occur in the Alps, equivalent to the American “considerable.” He pulled out two avalanche beacons—transmitters that would relay our location to rescuers—and set them to Send. We strapped them under our jackets.

外面有大約一英尺厚的原始雪粉。我彎下腰,用手摸了摸。它的顏色像糖果的純白色,又有海鹽的質地。胡戈寧掏出他的手機。該地區的雪崩預報將我們覆蓋在橙色地區。他說:“我們處于第三級”,這是阿爾卑斯山雪崩死亡人數最多的風險類別,相當于美國人所說的“非常嚴重的程度”。他拿出兩個雪崩信標——即可以向救援人員傳遞我們位置的發射器——并將它們設置為發送信號狀態。我們把它們綁在我們的外套下面。

“My job before working at the S.L.F. was at a cement plant,” Huguenin said, as we set out. (He was an engineer there.) “It was so loud.” Now we could hear the river as we walked. Beneath the blue sky, ours were the only tracks. After twenty minutes, the site came into view: a broad, bare mountainside, eight thousand feet high. Between two couloirs—the main avalanche paths—a half-dozen chalets huddled near a small wood.

“我在雪崩研究所工作之前的工作位于一家水泥廠”,胡戈寧在我們出發時說道。(他是那里的工程師。)“那里太吵了?!爆F在,我們可以邊走邊聽到河水的聲音。在藍色的天空下,我們的足跡是唯一的痕跡。二十分鐘后,那個地點出現在眼前:是一個寬闊且光禿禿的山坡,高達八千英尺。在兩條雪道(主要的雪崩通道)之間有六座木屋蜷縮在一片小樹林附近。

“They are not allowed to live here in the winter,” Huguenin said. Two days earlier, there had been a naturally occurring glide avalanche at the site. I asked whether it had been dangerous. “You would be dead,” he said. “No chance.”

“他們在冬天不允許住在這里”,胡戈寧說道。兩天前,該地曾發生過一次自然的滑坡雪崩。我問它是否有危險?!澳銜赖摹?,他說,“沒有機會逃生”。

The site was built in 1997; in the winter of 1999, the snow was the heaviest it had been since 1951—perfect conditions for an experiment. Using explosives dropped from a helicopter, the S.L.F. triggered three avalanches in the course of a month. They were so massive that they destroyed most of the institute’s equipment. If you had been skiing on the mountain during the last avalanche, you might have heard a soft exhalation: air releasing from a crack in the slab. Upslope, it would have looked as though someone had slit the mountain’s forehead. Now its face was falling off; the break, nine football fields across, was as deep as eleven feet in places. Blocks of snow would begin leaping up prettily, breaking like roiling water. In the quiet, you might feel something lapping at the back of your legs before being swept off your feet.

這塊場地建于1997年;1999年冬天的降雪是1951年以來最厚的一次——這是進行實驗的完美條件。雪崩研究所使用從直升機上投放的炸藥,在一個月內引發了三次雪崩。它們的規模是如此巨大,以至于摧毀了該研究所的大部分設備。如果你在最后一次雪崩期間在山上滑雪,你可能會聽到輕輕的呼氣聲:空氣從石板的裂縫中釋放出來。在斜坡上,看起來就像有人在山的額頭上劃了一刀?,F在,它的臉正在脫落;裂縫有九個足球場那么寬,有些地方深達11英尺。塊狀的雪開始躍起,劃出漂亮的曲線,像沸騰的水一樣破碎。在安靜的環境中,你可能會感覺到有什么東西在你的腿后面拍打,然后你就被卷走了。

The slide generated a powder cloud nearly two hundred feet high. It seemed to move in slow motion, like dry ice billowing, but it levelled the trees. Underneath, the core was formed by four hundred thousand tons of snow. Huguenin asked me to visualize the test peak, two kilometres distant, and the peak of the mountain on which we stood as the two sides of a half-pipe. With a deep roar, he said, the avalanche had run through the valley like a skateboarder, with enough speed to climb the other side.

滑道產生了近兩百英尺高的粉末云。它似乎在進行慢動作的移動,就像干冰在滾動,但它把樹木夷為平地。表面之下的核心是由四十萬噸的雪形成的。胡戈寧讓我把兩公里外的實驗山峰和我們所站的山峰想象成一條半管滑道的兩邊。他說,隨著一聲低沉的吼叫,雪崩像滑板運動員一樣穿過山谷,以足夠的速度爬上另一邊。

“It came all the way up there?” I asked, pointing to the top of our peak, three hours’ hike away.

“它一路來到那里?”我指著我們徒步三個小時才抵達的山頂問道。

“Yup, and there is a trail there. One of the wards was on it. The guy at that time saw a huge amount of snow jumping the top here”—he motioned toward the ridgeline above us—“and falling on the other side.” As the snow poured over the ridge, the warden could hear tree trunks snapping like matchsticks. “He really thought he was going to die,” Huguenin said. The experiment, which destroyed much of the forest, didn’t go over well with the locals.

“是的,而且那里有一條小路。其中一個監視員就在上面。當時那個人看到大量的雪躍到這里的山頂上”——他指向我們上方的山脊線——“并落在了另一邊”。當雪傾瀉在山脊上時,監視員可以聽到樹干像火柴棍一樣折斷的聲音?!八娴囊詾樽约核榔趯⒅痢?,胡戈寧說道。這個實驗摧毀了大部分的森林,當地人對它很不滿。

Huguenin and I continued walking. To our left, a Soviet-looking bunker poked out of the hill. It was two stories tall; in the 1999 experiment, it had been covered by thirteen feet of snow. To reach the observers buried inside, a crew had to cut a vertical tunnel with a chainsaw. Near the bunker, an array of continuous-wave radar antennas, designed to measure the flow at the avalanche’s core, craned toward the peak. Huguenin pointed to “obstacles” on the slope—pressure and velocity sensors mounted on concrete-and-steel structures. Against the mountainside, the largest obstacle, a sixty-foot-tall pylon studded with flow-measurement devices, looked like a toothpick.

胡戈寧和我繼續向前走。在我們的左邊,一個看起來像蘇聯人碉堡的建筑從山上探出頭來。它有兩層樓高;在1999年的實驗中,它已經被13英尺的雪覆蓋。為了接近埋在里面的觀察員,工作人員不得不用電鋸切開一條垂直的隧道。在掩體附近,有一個連續波雷達天線陣列,旨在測量雪崩核心的流量,并向山峰方向伸展。胡戈寧指著斜坡上的“障礙”——那是安裝在混凝土和鋼結構上的壓力和速度傳感器。在山坡上,最大的障礙物是一個60英尺高的塔架,上面鑲有流量測量裝置,它看起來像一根牙簽。

Avalanche country is like bear country. The threat hardly ever comes, but it defines the place, and lends it its grandeur. Outside the bunker, the mountains rose around us; flat clouds gathered in a distant valley like steam. We had lunch: bread, cheese, chocolate. The snow was warming in the sun. Scooping it up, I found that, instead of seeping through my fingers, it now formed a perfect snowball—metamorphism within a matter of hours. I thought of how plants observed in time lapse seem to move with animal purpose. I imagined the crystals in this newly fallen snow sintering and crackling with life.

雪崩地區就像熊出沒之地。威脅幾乎不會到來,但它卻定義了這個地方,并賦予它宏偉的氣勢。在掩體外,山脈在我們周圍升起;平坦的云層像蒸汽一樣聚集在遠處的山谷里。我們吃了午飯:面包、奶酪、巧克力。雪在陽光下變暖。我把它舀起來,發現它不再從我的手指縫中滲出,而是在幾小時內形成了一個完美的雪球——它在變形。我想到了在延時攝影中觀察到的植物似乎是帶著動物性的目的移動的。我想象著這些新落下的雪中的晶體在融結,發出噼里啪啦的聲音。
原創翻譯:龍騰網 http://www.codygalaherlaw.com 轉載請注明出處


From where we were sitting, we could see the glide avalanche from two days earlier. It was hard to get a sense of scale. Huguenin handed me his binoculars. Through them, I saw chest-high boulders of snow. Without them, the avalanche was a scratch on the mountainside.

從我們坐的地方,我們可以看到兩天前的滑動雪崩。這很難讓人感受到它的規模。胡戈寧把他的雙筒望遠鏡遞給我。通過望遠鏡,我看到了齊胸高的雪壘成的巨石。如果沒有望遠鏡,雪崩只是山坡上的一道劃痕。

One is unlikely to encounter an avalanche on the bomb-cleared trails of a ski resort like Alta. Avalanche accidents happen far more often in the backcountry, where skiers search for what the First Nations author Richard Wagamese called “the great white sanctity of winter.” In a recent survey, more than half of backcountry skiers said they had triggered an avalanche; a quarter said they’d got caught in one. It’s telling that the standard kit separating them from resort vacationers consists of a beacon, a probe, and a shovel.

在阿爾塔這樣的滑雪勝地,人們不太可能在已清除炸彈的小路上遇到雪崩。雪崩事故更經常發生在野外,在那里,滑雪者尋找《第一民族》的作者理查德·瓦加梅斯所說的“冬天的偉大白色圣地”。在最近的一項調查中,超過一半的越野滑雪者說他們曾引發過雪崩;四分之一的人說他們曾被卷入雪崩。這說明,將他們與度假區度假者區分開來的標準裝備包括一個信標、一個探測器和一把鐵鍬。

I grew up skiing at small mountains in the Laurentians, just north of Montreal. Well groomed and popular, they were often scraped to ice. It was only a few years ago that I went with a friend to a large ski resort in Colorado. One day, we travelled to a remote part of the mountain. There had been fresh snow that morning, and I whooped as I dropped in, not another soul in sight. The snow felt like a cloud underfoot; falling evoked the childhood joy of jumping in leaves. Carving slow curves, I recognized the feeling of discovery: I was writing my name on the mountain. I also understood, for the first time, how powder and silence lure skiers into the backcountry.

我從小就在蒙特利爾北部的勞倫蒂斯山脈的小山上滑雪。這些山峰修整得很好,很受歡迎,經常被滑成冰道。只是在幾年前,我和一個朋友去了科羅拉多州的一個大型滑雪場。有一天,我們去了山上的一個偏遠地區。那天早上下起了新雪,我一落腳就大聲呼喊,目光所及沒有一個人。雪感覺就像腳下的云;落下時喚起了我童年時在樹上跳躍的快樂。在緩慢的彎道上,我認識到這種發現的感覺。我在山上寫下了自己的名字。我也第一次明白,雪粉和寂靜是如何引誘滑雪者進入雪地深處的。

To some extent, backcountry skiers can rely on avalanche forecasts. At the Utah Avalanche Center (motto: “Keeping You on Top”), forecasters make daily field observations (“+” means fresh snow; “.” round grains; “?,” depth hoar), integrating them into uncannily specific recommendations: “It remains possible to trigger a wind slab avalanche. . . . This snow will feel upside down and stiff.” Different kinds of terrain are assigned levels of danger, on a one-to-five scale; colorful diagrams with cartoon icons show which parts of the mountain—above the treeline, say, or southern aspects—are to be avoided.

越野滑雪者在某種程度上可以依靠雪崩預報。在猶他州雪崩中心(其座右銘是:“讓你站在頂峰上”),預報員每天進行實地觀察(“+”表示新雪;“.”表示雪籽;“?”表示深度結霜),將它們整合成令人難以置信的具體建議:“仍然有可能引發風成板狀雪崩……這種雪會讓人感到上下顛倒和僵硬?!辈煌愋偷牡匦伪粍澐譃橐恢廖寮壍奈kU等級;帶有卡通圖標的彩色圖表標識了山體的各個部分——比如說在樹木生長線以上的地區,或者南坡區域——是應該避免前往的。

Some experts worry that such diagrams give skiers a false sense of security. My sixty-seven-year-old godfather, Richard, happens to be the most experienced backcountry adventurer I know; a snowboarder for decades, he has logged more than a hundred thousand vertical metres in the past two years, in Kashmir, Antarctica, and other places. In the backcountry, he relies not just on forecasts but also on guides, to whom he attributes extraordinary diagnostic powers. Before taking a group out, a guide might dig a small column out of the slope. He’ll examine the layers, sussing out weakness, assessing the look of the crystal grains. Then he’ll tap the top of the column with his hand ten times, bending from the wrist. If the column survives, he’ll do it again, bending from the elbow; finally, he’ll do it from the shoulder. His interest is in when the column collapses, and how. Once, on a slope that seemed risky, a guide told Richard’s group that, whatever they did, they must follow, one by one, to the right of his line. Each skier followed in turn, carefully staying to his right. As Richard descended, a layer of snow unsettled beneath him, a few feet to the left of the guide’s tracks, and sent a wave across the bowl. The slope fell like a sheet.

一些專家擔心,這樣的圖示會給滑雪者帶來虛假的安全感。我六十七歲的教父理查德恰好是我認識的最有經驗的越野冒險家;他玩了幾十年的滑雪,在過去兩年里,他在克什米爾、南極洲和其他地方進行了十多萬米的垂直化學。在雪地深處,他不僅依靠預測,還依靠向導,他把非凡的判斷能力歸功于他們。在帶一個小組出去之前,向導可能會從斜坡上挖出一個小圓柱。他將檢查各層,找出弱點,評估晶體顆粒的外觀。然后他用手敲擊柱子的頂部十次,從手腕處開始彎曲。如果柱子還在,他將再次這樣做,從肘部開始彎曲;最后,他將從肩部開始做。他的興趣在于柱子何時倒塌,以及如何倒塌。有一次,在一個看起來很危險的斜坡上,一個向導告訴理查德的團隊,無論他們做什么,他們必須一個一個地跟在他的隊伍右邊。每個滑雪者依次跟上,小心翼翼地呆在他的右邊。當理查德下降時,在他腳下,在向導的足跡左邊幾英尺的地方,有一層雪松動了,并在低洼地區掀起了波浪。斜坡上的雪呈片狀滑下去。

One way to avoid avalanches is to ski shallower slopes. Slopes of around twenty-five degrees are perfectly enjoyable; steeper ones are only marginally more fun. And yet it’s hard for skiers to hold back. “The tricky part is controlling our lust,” a forecast reads. After a student of his died in an avalanche, Jordy Hendrikx, a professor at Montana State University, shifted his focus from geophysical research to behavioral science. (“Understanding how a crystal grows is not enough to change the current fatality profile,” he told me.) In one long-running study, he had a large group of backcountry skiers log their activity with a G.P.S.-enabled app. He found that experts chose steeper terrain, as did all-male groups, especially younger ones. (“Quantifying the obvious,” he has said.) When Tremper published his book, in 2008, he reported that, although a third of those who used the backcountry in Utah were women, women accounted for only 3.3 per cent of fatal accidents.

避免雪崩的一個方法是滑較淺的山坡。二十五度左右的斜坡是完全可以縱情享受的;更陡峭的斜坡只會增加一點樂趣。然而滑雪者卻很難安耐得住?!白罴质强刂莆覀兊挠?,”一份預報中如此寫道。在他的一個學生死于雪崩之后,蒙大拿州立大學的教授喬迪·亨德利克斯將他的注意力從地球物理研究轉移到了行為科學上。(他告訴我說:“了解晶體的生長過程并不足以改變目前的死亡狀況”。)在一項長期的研究中,他讓一大群越野滑雪者用一個支持全球定位系統的應用程序記錄他們的活動。他發現,滑雪行家們選擇了更陡峭的地形,所有男性群體也是如此,尤其是年輕群體。(他說:“量化顯而易見的事實”。)當特倫普在2008年出版他的書時,他報告說,盡管在猶他州越野滑雪的人中有三分之一是女性,但女性只占致命事故的3.3%。

In the early two-thousands, when no amount of snow science seemed to be improving outcomes, the study of “human factors” that contributed to avalanche accidents became popular. Tremper lists six common “heuristic traps” that lead to avalanche fatalities: doing what is familiar; being committed to a goal, identity, or belief; following an “expert”; showing off when others are watching; competing for fresh powder; and seeking to be accepted by a group. The Swiss pocket guide for backcountry skiers is full of technical information about slabs and slope angles, but it also includes the advice “Don’t give in to temptation!”

在21世紀00年代早期,當任何數量的雪的科學似乎都無法改善結果時,對導致雪崩事故的“人為因素”的研究開始流行。特倫普列出了導致雪崩死亡的六個常見的“啟發式陷阱”:做熟悉的事情;致力于一個目標、身份或信仰;跟隨“行家”;在別人觀看時炫耀;爭搶新鮮雪粉;以及尋求被團體接受。瑞士越野滑雪者袖珍指南中充滿了關于石板和斜坡角度的技術信息,但也包括“不要向誘惑屈服”的建議。

New pilots are said to be most accident-prone right after their hundred- and-fiftieth hour; that’s when self-confidence peaks. Dave Richards, the Alta avalanche director, told me that, for many skiers, danger is highest right after the completion of an avalanche-avoidance course. The backcountry is what behavioral scientists call a “wicked” environment for learning: it gives you no negative feedback until it kills you.

據說,新飛行員在第150小時后最容易發生事故;那是自信心的高峰期。阿爾塔雪崩主管戴夫·理查茲告訴我,對許多滑雪者來說,在完成雪崩規避課程后,危險性最高。雪地深處是行為科學家所謂的“邪惡”的學習環境:它不給你任何負面反饋,直到它殺死你。

A database maintained by the Colorado Avalanche Information Center contains aviation-style tick-tock accounts of avalanche fatalities. In January, 2019, a group of skiers taking a backcountry avalanche course went out with their instructor for a day in the field. The skiers followed a methodical, rigorous plan. At predetermined waypoints, the group assessed the conditions; they dug a snow pit, testing a snow column for strength. Their plan for the day included slope angles for all the terrain they might encounter. But they didn’t measure the steepness in the field themselves, and one particular slope that they believed to be no more than twenty-nine degrees was actually thirty-two degrees. As the second of six skiers proceeded downward, the other four, waiting above, sidestepped in order to see his progress more clearly. The slope avalanched twice—the first one remote-triggered the second—and the second skier was buried.

科羅拉多雪崩信息中心維護的一個數據庫包含了雪崩致人死亡的航空鐘記錄。2019年1月,一群參加越野雪崩課程的滑雪者與他們的教官一起出去實地考察了一天?;┱邆冏裱粋€有條不紊的嚴格計劃行進。在預先確定的地點,該小組評估了條件;他們挖了一個雪坑,測試雪柱的強度。他們當天的計劃包括他們可能遇到的所有地形的坡度角。但是他們并沒有親自測量現場的坡度,而其中一個斜坡——他們認為不超過29度——實際上是32度。當六個滑雪者中的第二個人向下走時,在上面等待的另外四個人側身避開,以便更清楚地看到他的進展。山坡上發生了兩次雪崩,第一次雪崩遠遠地觸發了第二次雪崩,第二個滑雪者被埋在了雪中。

Two skiers turned their beacons to Search, monitoring their screens. They assembled their tent-pole-like probes, jamming them into the ground until they struck the buried skier. It took more than twenty-five minutes to shovel the victim out. The report, which identifies “a Persistent Slab avalanche problem,” is longer than most, at pains to explain why this group—so well informed and meticulous—could still be caught.

兩名滑雪者將他們的信標轉向搜索模式,監測他們的屏幕。他們組裝了他們的帳篷桿一樣的探測器,把它們塞進地面,直到它們擊中被埋的滑雪者。他們花了超過二十五分鐘才將受害者鏟出來。這份報告指出了 “持續的板狀雪崩問題”,它比大多數報告都要長,不厭其煩地解釋為什么這群人——消息如此靈通、如此一絲不茍——仍然會撞上雪崩。

On my first night at Alta, I stayed at one of the lodges. Since the road had closed, the cheap dorms filled up, four to a room. One man, Bill, forty-five years old, took a bottom bunk. A week earlier, he’d been in an avalanche—small, he said, and soft-slab. I asked him what it was like. “Manageable, and managed,” he said. He’d realized that the slope had the potential to slide, but he knew what to do if that happened, so he skied it anyway. “I did a couple tomahawks,” he said—tumbling end over end for three hundred feet, then standing up. Was he shaken? He thought about it. Actually, he said, he was serene. “Manageable, and managed,” he repeated, from his bed.

在阿爾塔的第一個晚上,我住在其中一個旅館里。由于道路已經關閉,廉價的房間內已經滿員,當時是四個人一個房間。一個叫比爾的人,四十五歲,住在下鋪。一周前,他經歷了一次雪崩——他說,規模很小,而且是軟性板狀雪崩。我問他那是什么感受。他說:“可以應付,而且我應付過來了”。他意識到這個斜坡有可能滑動,但他知道如果發生這種情況該怎么做,所以他還是滑了過去?!拔易隽藥讉€戰斧式的動作”,他說道——在三百英尺的距離內翻來覆去,然后站起來。他是不是被嚇到了?他想了想。事實上,他說道,當時他很平靜。他在床上重復說著:“可以應付,而且我應付過來了”。

Toward the end of my time in Switzerland, I spent the day with Stefan Margreth, S.L.F.’s chief civil engineer. Easygoing, he wore a pink-and-red winter hat. At the institute, Margreth is the spiritual descendant of Johann Coaz: he carries Switzerland’s avalanche-hazard maps in his head. Margreth sometimes uses ramms to model avalanche risk. “It’s a great honor that he even uses the program,” Bartelt, its creator, said.

當我在瑞士的時間即將結束時,我和雪崩研究所的首席土木工程師斯特凡·馬格雷特共處了一天。他很隨和,戴著一頂粉紅色的冬帽。在研究所,馬格雷特是約翰·科茲的精神后裔:他腦子里裝著瑞士的雪崩危險地圖。馬格雷特有時會用快速大規模運動模擬軟件來模擬雪崩風險?!八谑褂眠@個程序,這對我而言是一個巨大的榮譽”,該軟件的發明者巴特爾說道。

Many Swiss towns have building restrictions based on avalanche-hazard maps. “Everyone in the Swiss mountains knows their red zones and blue zones,” Margreth told me. We drove to St. Ant?nien, a tiny farming village an hour outside Davos. The threat of avalanche there is so great that, in storms, residents wear beacons while tending their farms. Margreth helped design or approve nearly every avalanche-mitigation measure in town: a huge concrete wedge on the upslope side of the elementary school; vast lines of steel girders high in the starting zones; houses built into the sides of hills, so that snow slides right over them.

許多瑞士城鎮都有基于雪崩危險地圖的建筑限制。馬格雷特告訴我,“瑞士山區的每個人都知道他們的紅區和藍區”。我們驅車前往達沃斯外一小時車程的圣安托尼恩,這是一個小小的農業村。那里的雪崩威脅如此之大,以至于在暴風雨中,居民們在打理農場時都要佩戴信標。馬格雷特幫助設計或批準了鎮上幾乎所有的雪崩緩解措施:在小學的上坡一側有一個巨大的混凝土楔子;在雪崩爆發區高處有大量的鋼梁;房屋建在山的兩側,這樣雪就會從它們上面滑過。

After the winter of 1951, a party from the federal government in Bern travelled to St. Ant?nien to discuss the question of resettlement. The townspeople wanted to stay. “The Swiss mentality is to let people live in the mountains,” Margreth said. Taxpayers spent millions of dollars on mitigation measures; roads running up the mountain had to be built just to transport construction equipment. I asked Margreth why people had moved to St. Ant?nien in the first place. “The good places had been taken,” he said, smiling. In Switzerland, even the mountains are crowded.

1951年冬天過后,伯爾尼聯邦政府的一個代表團來到圣安托尼恩,討論重新安置當地居民的問題。鎮民們想留下來。馬格雷特說:“瑞士人的心態是讓人們住在山里”。納稅人花了幾百萬美元來采取緩解措施;為了運輸建筑設備,不得不修建上山的道路。我問馬格雷特,為什么人們最初搬到了圣安托尼恩。他笑著說:“好地方都被占了。在瑞士,即使是山區也很擁擠”。

A few years back, Margreth was contacted by the emergency-programs manager and avalanche forecaster for the city of Juneau, Alaska. Several neighborhoods were in the runout zones of slide paths; it was probably the most significant avalanche problem in the United States. Could anything be done? Even if tens of millions of dollars were spent on mitigation, the houses could not be completely protected; their destruction was more or less inevitable. Margreth suggested that the city buy the owners out and keep people from building new homes. So far, this has proved politically impossible; the city of Juneau, which had already bought a few empty lots in the area, has invested in warning systems and road-protection protocols.

幾年前,阿拉斯加朱諾市的應急計劃經理和雪崩預報員聯系了馬格雷特。有幾個街區位于滑道的沖出區;這可能是美國最嚴重的雪崩問題。有什么辦法嗎?即使花費數千萬美元用于減災,這些房屋也不可能得到完全的保護;它們的毀滅或多或少是不可避免的。馬格雷特建議城市將業主的產業買下來,不讓人們再建新房。到目前為止,這在政治上被證明是不可能的;朱諾市已經買下了該地區的幾塊空地,在警告系統和道路保護協議方面進行了投資。

“Sometimes you need accidents,” Margreth said. Atwater, in his book, suggests that “people need a good scare not less than every three years. Otherwise they begin to think that avalanche hazard is a figment of someone’s imagination.”

“有時你需要事故”,馬格雷特說道。阿特沃特在他的書中建議,“人們需要不少于每三年一次的良性恐嚇。否則他們就會開始認為雪崩危險是某人的臆想”。

They can seem absurd to us, these people living at the base of steep hills. Don’t they know they’re idling in the face of disaster? The feeling was in the air in Switzerland, though not because of avalanches. As we walked on the road toward the edge of town, we saw diners enjoying themselves at sidewalk tables. “It’s much too warm for a February day,” Margreth said, in the winter sun. It had been three years since the team at the test site performed an experiment. Not enough snow had fallen.

在我們看來,這些住在陡峭山腳下的人可能非常不可理喻。難道他們不知道他們在災難面前毫無還手之力嗎?瑞士的空氣中彌漫著這種感覺,盡管不是因為雪崩。當我們走在通往城鎮邊緣的路上時,我們看到食客們在人行道上的桌子上享受生活。馬格雷特在冬日的陽光下說:“對于二月的天來說,現在太溫暖了”。自從試驗場的團隊進行實驗以來,已經過去三年時間了。雪下得還不夠多。

原創翻譯:龍騰網 http://www.codygalaherlaw.com 轉載請注明出處