Snow Science Against the Avalanche

對(duì)抗雪崩的雪科學(xué)

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(dǎo)致不穩(wěn)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(shí)候的一個(gè)晚上，離開猶他州阿爾塔市的唯一道路被關(guān)閉了。在滑雪旅館，告示牌警告客人留在室內(nèi)，否則將面臨罰款。那個(gè)季節(jié)已經(jīng)下了22英尺的雪，而在前一天，一場風(fēng)暴就降下了33英寸的雪；預(yù)計(jì)到早上還會(huì)有1英尺。發(fā)生雪崩的最危險(xiǎn)時(shí)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(gè)衡量道路危險(xiǎn)性的標(biāo)準(zhǔn)——雪崩危險(xiǎn)指數(shù)就是根據(jù)雪崩的大小和頻率以及暴露在雪崩中的車輛數(shù)量來計(jì)算風(fēng)險(xiǎn)。雪崩危險(xiǎn)指數(shù)為10時(shí)被認(rèn)為是中等水平；達(dá)到40時(shí)，該道路就需要全職雪崩預(yù)報(bào)員的關(guān)注。而從山上延申到鹽湖城210號(hào)州際公路如果不加保護(hù)，其雪崩危險(xiǎn)指數(shù)將達(dá)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(diǎn)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(xiàng)目的負(fù)責(zé)人戴夫·理查茲坐在控制室里。墻上掛著地圖和標(biāo)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(fēng)速和溫度數(shù)據(jù)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(duì)士兵的氣質(zhì)。他穿著一件背心，上面綁著一臺(tái)收音機(jī)，拿著一罐浸漬煙草，偶爾向辦公桌下的垃圾桶吐口水。當(dāng)人們說他從事雪崩控制工作時(shí)，他表示反對(duì)；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(hù)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(dāng)天的首席雪崩預(yù)報(bào)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(kuò)展傾向還是一個(gè)問號(hào)”，他說，“板塊中沒有很多雪體……干燥面長達(dá)兩到三英里?！彼^續(xù)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(xiàn)為小顆粒狀?！?/b>

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(biāo)有“舊爆炸物清單”的夾子。摩根解釋說，這個(gè)想法是為了“射擊我們無法到達(dá)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(biāo)定位計(jì)劃?；﹫鍪亲陨隙虑謇淼模菏紫仁桥趶棧缓笫鞘至駨?。在發(fā)射任何炮彈之前，通往山上的道路都將被關(guān)閉。因?yàn)椴皇撬械幕┱叨紙?jiān)持走梳理過的小路——越野冒險(xiǎn)家們會(huì)尋找偏遠(yuǎn)地區(qū)——猶他州交通局也會(huì)檢查路邊的痕跡。有時(shí)，在批準(zhǔn)之前，它還會(huì)用紅外線攝像機(jī)在山坡上進(jìn)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(xù)向前十四步？”理查茲說，“不包括17號(hào)點(diǎn)?！倍d子坡是度假村的一個(gè)山坡，他們計(jì)劃向其發(fā)射14枚炮彈；17號(hào)點(diǎn)是其山脊線上的一個(gè)點(diǎn)。
“17號(hào)點(diǎn)并不算最糟糕的主意，”摩根同意，“你要向那里發(fā)射7枚炮彈？”
“禿子坡最后一次被射擊是什么時(shí)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(tái)球桌、墻上的鹿頭——吃早餐。五點(diǎn)半的時(shí)候，滑雪纜車開動(dòng)了。當(dāng)理查茲走出門時(shí)，另一位滑雪巡邏員麗茲·羅科提到，她已經(jīng)準(zhǔn)備好了一些他們那天早上要用的手榴彈。“我將點(diǎn)燃它們，并把它們?nèi)舆M(jìn)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?cè)谠鹿庀鲁俗娞萆先?。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(dāng)了33年的巡邏員，他的母親后來成為一名大學(xué)管理人員，在拉斯特爾旅館的前臺(tái)工作。理查茲以職業(yè)滑雪者的身份開始了他的職業(yè)生涯，然后擔(dān)任直升機(jī)滑雪向?qū)?，最后全職加入巡邏?duì)。他說：“對(duì)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(dāng)?shù)臈l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?！?/b>

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(gè)聲音在無線電中噼里啪啦地響起?！笆盏?，”理查茲說道，“當(dāng)你扣動(dòng)扳機(jī)時(shí)，吱一聲?！?一會(huì)兒，無線電又響了起來；理查茲躲了起來，捂住了頭，附近某個(gè)地方發(fā)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(gè)兩層樓的棚子。一扇車庫的門打開了，里面有一對(duì)一百零五毫米的榴彈炮，它們是第二次世界大戰(zhàn)的產(chǎn)物，安裝在半圓形的軌道上。炮管對(duì)準(zhǔn)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(jìn)一根炮管來清潔它?！耙粋€(gè)星期天的早晨，”他開始對(duì)自己唱歌，“當(dāng)我走在路上……”

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(jī)；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(zhuǎn)動(dòng)一個(gè)曲柄，炮管向第一個(gè)目標(biāo)擺動(dòng)。
“零，零，二，七，”理查茲大喊——這是仰角和偏轉(zhuǎn)度。另外兩名巡邏員確認(rèn)了這一坐標(biāo)?！皽?zhǔn)備開火，”理查茲喊道：“開火！”
他用力拉動(dòng)一條鐵鏈。炮口一閃，一縷刺鼻的煙霧彌漫在空氣中，發(fā)出了一陣高亢的響聲。
原創(chuàng)翻譯：龍騰網(wǎng) http://www.top-shui.cn 轉(zhuǎn)載請(qǐng)注明出處


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(bào)告！”在外面，當(dāng)炮擊繼續(xù)進(jìn)行時(shí)，一個(gè)名叫凱爾的巡邏員從他的背包里拿出了一個(gè)小型助推炸藥：它就像兩個(gè)豆子罐頭用甘草連在一起，是一種卡通版的炸彈。他拉開導(dǎo)火線，暗中把它扔到了懸崖邊上。他說：“這不是我想要的結(jié)果”。90秒后，它爆炸了，變成一團(tuán)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(dāng)一切完成后，已近九點(diǎn)。理查茲準(zhǔn)備滑回基地。夜里，度假村向阿爾塔的滑雪者發(fā)出警報(bào)，告訴他們預(yù)計(jì)會(huì)有9至14英寸的新降雪——這可以算是本季最好的滑雪機(jī)會(huì)之一了。在下山的路上，陽光照耀著新鮮的雪粉，它直達(dá)理查茲的腰部。當(dāng)他下山時(shí)，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(dāng)作一個(gè)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(jìn)了一個(gè)空洞。在雪沉淀和漂移之后，可能會(huì)出現(xiàn)雪崩。

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(xiàng)目至少可以追溯到1397年，在瑞士的安德馬特，有一項(xiàng)禁止伐木的法律。瑞士農(nóng)民已經(jīng)搬到了更遠(yuǎn)的山里。他們的新農(nóng)舍坐落在雪崩的道路上。人們很快發(fā)現(xiàn)，古老的樹木可以固定住雪，使滑坡不至于聚集成一團(tuán)。十八世紀(jì)七十年代，瑞士林業(yè)局局長約翰·科茲對(duì)歷史上的雪崩進(jìn)行了記錄。他繪制了潛在災(zāi)害區(qū)的地圖，并設(shè)計(jì)了保護(hù)脆弱居民點(diǎn)的墻壁；用于建造墻壁的石頭由數(shù)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(shí)間，美國西部的勘探者開始在高山上發(fā)現(xiàn)銀礦。在阿爾塔，最初建造的一個(gè)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(jù)傳說，雪崩的危險(xiǎn)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(jià)暴跌時(shí)遭到了遺棄，但在1930年代，歐洲風(fēng)格的滑雪勝地遍布美國西部。1939年，阿爾塔出現(xiàn)了第一條機(jī)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(zhàn)后，美國第十山地師的一些退伍軍人——他們?cè)邮苓^高山作戰(zhàn)的訓(xùn)練——開始負(fù)責(zé)度假區(qū)的雪地安全。1945年，曾在第10師戰(zhàn)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(shí)興起就去申請(qǐng)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(gòu)想為這個(gè)大陸上的第一個(gè)雪崩研究中心，而我在那里決定冒險(xiǎn)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(gè)風(fēng)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(fēng)暴系統(tǒng)在鹽湖中積累水分，當(dāng)它們上升到山區(qū)時(shí)，每年冬天會(huì)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(jié)，形成六角形的雪花——但之后卻可以采取無數(shù)的形式。雪的行為既像固體又像液體：它在流動(dòng)——甚至山坡上的一片雪毯也在緩慢地蠕動(dòng)——同時(shí)保持其結(jié)構(gòu)?？茖W(xué)家認(rèn)為它是“溫暖的”，因?yàn)樗偸墙咏淙埸c(diǎn)。這就是為什么在你做今天的第一個(gè)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(tài)的材料。這就如同用燒紅的鋼建造一座橋。
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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(rèn)為山上的雪是一個(gè)固體塊。實(shí)際上，它是一個(gè)由連續(xù)降雪形成的層狀蛋糕，每一層都是獨(dú)特的、可改變的。阿特沃特寫道：“雪層從未處于靜止?fàn)顟B(tài)，它不斷地被推、被拉、被壓、被彎曲、被加熱、被冷卻、被通風(fēng)、被攪動(dòng)?！弊钌厦娴囊粚涌赡苷谡舭l(fā)到夜晚的空氣中；同時(shí)，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(dāng)各層之間的溫差較小時(shí)，雪往往會(huì)熔結(jié)，或凝聚在一起：晶體相互撞擊，成為圓形的顆粒，融合成一個(gè)堅(jiān)固、密集的雪堆。當(dāng)溫差較大時(shí)，例如，在雪塊和地面之間，雪向上蒸發(fā)并重新凍結(jié)，形成空心的杯狀晶體。其結(jié)果是脆性的、帶刺的雪，被稱為深度囤積物。(在冰激凌中，一個(gè)類似的過程產(chǎn)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(wěn)定的雪還是脆弱的白霜，其本身都不危險(xiǎn)。當(dāng)一個(gè)密集的雪層位于一個(gè)脆弱的雪層之上時(shí)，問題就出現(xiàn)了，因?yàn)閮烧咧g結(jié)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(qiáng)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(jié)構(gòu)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(gè)詞對(duì)于它所描述的現(xiàn)象來說太過優(yōu)雅了。積雪在足夠淺的斜坡上，但它又足夠陡峭，使雪不穩(wěn)定——據(jù)說最有效的坡度是39度——雪層會(huì)分離，板塊會(huì)開裂和滑動(dòng)。在激烈的攪動(dòng)下，雪在幾秒鐘內(nèi)達(dá)到每小時(shí)80英里的速度。一個(gè)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(shù)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(shù)人甚至不能移動(dòng)他們的手指。在幾分鐘內(nèi)，你的臉就會(huì)形成一個(gè)冰罩。你會(huì)因?yàn)樽约汉舫龅亩趸贾舷⒍馈?/b>

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(qū)的一個(gè)試驗(yàn)場，瑞士科學(xué)家引發(fā)了足以摧毀其設(shè)備的雪崩。

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 “l(fā)oose.” 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(xiǎn)的一種雪崩）中，整個(gè)雪崩層一次性被釋放出來。在風(fēng)暴雪崩或風(fēng)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(xù)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(xiǎn)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(yù)兆是“針輪”，即滾動(dòng)時(shí)留下條紋的小雪球構(gòu)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(shí)是干的，在坡度較低的地方變濕——已經(jīng)變得越來越普遍?；瑒?dòng)雪崩也是如此，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(xué)生必須等待大自然給他們帶來災(zāi)難，但雪崩是可以被引發(fā)的。在1950年，阿特沃特使用了一種現(xiàn)在稱為“滑雪切割”的技術(shù)。兩名巡邏員從危險(xiǎn)的山坡上下來；當(dāng)一名巡邏員看著，準(zhǔn)備進(jìn)行救援時(shí)，另一名巡邏員則滑到遠(yuǎn)處的一個(gè)安全點(diǎn)，提高足夠的速度，試圖穿越他可能引發(fā)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(duì)其他人來說也被認(rèn)為足夠穩(wěn)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(duì)每個(gè)山頭進(jìn)行滑雪切割并不切合實(shí)際。阿特沃特知道瑞士人用炸彈來對(duì)付雪崩，于是他動(dòng)用了林務(wù)局戰(zhàn)時(shí)供應(yīng)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(yuǎn)處的目標(biāo)。國民警衛(wèi)隊(duì)的人帶著第一次世界大戰(zhàn)時(shí)期的法國75型大炮來到了這里。（他后來寫道：“如果沒有戰(zhàn)爭遺留物，雪崩研究會(huì)是什么樣子？”）中距離目標(biāo)對(duì)火炮來說太近，但對(duì)徒步旅行或滑雪來說又太遠(yuǎn)，阿特沃特嘗試了槍榴彈、火箭筒、從直升機(jī)上投下的炸彈，以及一種被稱為“大老鼠”的空對(duì)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(gè)改良的發(fā)球機(jī)，即用于擊球練習(xí)的那種機(jī)器，成為了最可靠的投擲器械。理查茲的團(tuán)隊(duì)仍然使用阿特沃特的“雪崩機(jī)”，每天早上發(fā)射大約30發(fā)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(chuàng)建了一個(gè)“雪地研究區(qū)”——一個(gè)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(fā)現(xiàn)重量比深度重要得多：當(dāng)放置在一層白霜上時(shí)，一英尺的蓬松粉末比三英寸的稠密泥漿更危險(xiǎn)。他們了解到，風(fēng)可以在短短幾個(gè)小時(shí)內(nèi)存積許多英尺的雪；被風(fēng)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(shí)候?qū)懙溃骸拔覀兛吹皆谶@塊看似平靜的土地上發(fā)生的事情，以前沒有人看到過，甚至沒有人懷疑過?！彼偨Y(jié)說：“在雪層中顯然存在著隨機(jī)的塑性形變和流動(dòng)，其原因和影響不為人知，現(xiàn)在也是如此?！?/b>

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 “l(fā)eaves 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(xué)家弗朗西斯·博福特爵士開發(fā)了一個(gè)通過觀察測量海上風(fēng)速的標(biāo)尺。后來，它被調(diào)整為在陸地上使用。斯科特·胡勒在他2004年出版的《風(fēng)的定義》一書中認(rèn)為，該標(biāo)尺附帶的由無名氏創(chuàng)作的描述應(yīng)該算作文學(xué)作品。在蒲福0級(jí)，風(fēng)是“平靜的；煙霧垂直升起”。在蒲福3級(jí)，微風(fēng)柔和，人們看到“樹葉和小樹枝在不斷運(yùn)動(dòng)”。在蒲福5級(jí)，清新的微風(fēng)，“落葉的小樹開始搖擺；內(nèi)陸水域形成波浪”。詩意的描述將主觀印象與客觀現(xiàn)實(shí)聯(lián)系起來。疾風(fēng)——蒲福7級(jí)——?jiǎng)t是由“整棵樹在運(yùn)動(dòng)；逆風(fēng)行走不便”所定義。看到和感覺到這些東西，你就知道風(fēng)速在每小時(shí)三十二至三十八英里之間。

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(shè)計(jì)了一套類似的指南。他的語言是令人回味的，但描述中的權(quán)威性較低。他寫道：“不穩(wěn)定的濕雪是粘稠的，它從腳下溜走，滾成球狀或滑成毯狀……穩(wěn)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(fēng)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(gè)清晨，我沿著達(dá)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(dá)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(dāng)?shù)厝?；雪崩研究所在距離火車站幾分鐘的地方占據(jù)了一棟簡陋的建筑。大廳里的一個(gè)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(dāng)阿特沃特正在進(jìn)行炸藥實(shí)驗(yàn)時(shí)，瑞士經(jīng)歷了有史以來最嚴(yán)重的雪崩季節(jié)。十天內(nèi)下了十英尺的雪。大約一百人喪生；在雪崩中幸存了幾個(gè)世紀(jì)的村莊被摧毀了。成立于1942年的雪崩研究所突然成為一個(gè)具有國家意義的機(jī)構(gòu)。
原創(chuàng)翻譯：龍騰網(wǎng) http://www.top-shui.cn 轉(zhuǎn)載請(qǐng)注明出處


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(shí)驗(yàn)室的負(fù)責(zé)人右耳戴著一個(gè)耳環(huán)；在從事雪的研究之前，他獲得了理論凝聚物質(zhì)物理學(xué)的博士學(xué)位。他穿著牛仔褲、黑色耐克鞋和一件破舊的羊毛衫，把我領(lǐng)進(jìn)實(shí)驗(yàn)室，實(shí)驗(yàn)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(shí)驗(yàn)室的目標(biāo)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(jié)構(gòu)聯(lián)系起來”，洛維說道。他拿起一個(gè)手掌大小的立方體，看起來已經(jīng)被精心挖空了，就像白蟻巢的石膏模型。一個(gè)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(shí)留下的坑，然后用塑料在高倍鏡下進(jìn)行三維打印：這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(jīng)沉淀下來的頂層是一個(gè)緊密的雪團(tuán)，就像即食拉面?！叭绻覀冮_始剪切這個(gè)東西”——洛維在兩個(gè)雪層相接的地方做了一個(gè)切割的動(dòng)作——“它就有百分之九十九的把握會(huì)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(shí)驗(yàn)以來，雪的科學(xué)已經(jīng)有了長足的進(jìn)步?，F(xiàn)在可以在慢動(dòng)作中看到新落下的雪的晶體融結(jié)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(jié)晶的過程——冰塊的重新分離——更加神秘。洛維打開一個(gè)壁櫥，從一個(gè)標(biāo)有“Snowbreeder 3”的架子上拿出一個(gè)圓筒。該設(shè)備允許科學(xué)家在施加不同程度的熱量和壓力的同時(shí)觀察雪樣。在他的電腦前，洛維在Snowbreeder中播放了一段“雪的變質(zhì)”的延時(shí)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。”然后從下面施加熱量。下面的晶體開始向上面的晶體蒸發(fā)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(gè)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(duì)雪層的科學(xué)研究已經(jīng)完善了我們對(duì)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(xué)》雜志上發(fā)表了一項(xiàng)研究，模擬了當(dāng)厚重的雪層的一部分坍塌到一個(gè)薄弱的雪層上時(shí)，如何產(chǎn)生波浪。他們的模型解釋了現(xiàn)場的一個(gè)奇怪的觀察結(jié)果：滑雪者偶爾會(huì)在他們上方或下方引發(fā)致命的雪崩，即使是站在平坦的斜坡上。事實(shí)證明，薄弱層的行為就像床墊中的線圈：在一個(gè)地方施力，它就會(huì)散布到整個(gè)床上。這個(gè)概念現(xiàn)在是雪崩安全教育的一個(gè)基石，在那里它被簡單地稱為“遠(yuǎn)程觸發(fā)”。

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(yīng)用。洛維用手指旋轉(zhuǎn)著他的鑰匙，帶我參觀了這些寒冷的房間。在一個(gè)房間里，一個(gè)加濕器產(chǎn)生了完美的、實(shí)驗(yàn)室培育的粉末的小云團(tuán)；在另一個(gè)房間里，來自北極、芬蘭和冰島的雪被精心保存起來。科學(xué)家們正在研究雪的晶體結(jié)構(gòu)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(fā)蒼蒼的研究工程師佩里·巴特爾正在進(jìn)行快速大規(guī)模運(yùn)動(dòng)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(shù)十人死亡。土耳其研究人員急忙將兩次雪崩的數(shù)據(jù)交給了巴特爾?？焖俅笠?guī)模運(yùn)動(dòng)模擬軟件計(jì)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。

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(guī)模運(yùn)動(dòng)模擬軟件預(yù)測了雪崩的路徑和力量。它的核心創(chuàng)新是它能夠?qū)⒀┍酪暈?"顆粒剪切流"，利用統(tǒng)計(jì)學(xué)來平均化數(shù)百萬相互作用的雪粒的運(yùn)動(dòng)。想象一下一盒麥片，里面裝滿了片狀物和棉花糖；現(xiàn)在把它倒出來。一些碎片會(huì)直接飛起來，被它們自己的動(dòng)力帶著。其他的會(huì)被它們滑下去的表面抓住。許多片狀物會(huì)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(dòng)中，小東西會(huì)在大東西下面沉下去。）快速大規(guī)模運(yùn)動(dòng)模擬軟件試圖預(yù)測這種攪動(dòng)的結(jié)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(yàn)證——特別是關(guān)于樹木是否被撞倒的數(shù)據(jù)，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(jī)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(duì)模型進(jìn)行微調(diào)將需要更精確的數(shù)據(jù)，而這些數(shù)據(jù)很難得到。收集這些信息將需要在雪崩內(nèi)部或下方進(jìn)行讀數(shù)。
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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(gè)雪崩試驗(yàn)場——這是一片離達(dá)沃斯約200英里的陡峭山區(qū)。聽到 “試驗(yàn)場“這個(gè)短語，人們可能會(huì)想到一塊平緩滑雪坡。但實(shí)際上，它是一座不可能是為科學(xué)保留的巨大的山。
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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(xué)家是貝蒂·索維拉，她是一位水力學(xué)工程師。當(dāng)我們?cè)谘┍姥芯克娒鏁r(shí)，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?guī)模運(yùn)動(dòng)模擬軟件是一個(gè)非常簡化的模型，”她說。試驗(yàn)場的目標(biāo)是開發(fā)一個(gè)更真實(shí)的版本，通過對(duì)雪層的詳細(xì)測量與它所產(chǎn)生的雪崩相關(guān)聯(lián)。她對(duì)滑動(dòng)雪崩特別感興趣：每年都有更多的滑動(dòng)雪崩，但它們難以捉摸。她說：“你無法預(yù)測它們何時(shí)被釋放。這確實(shí)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(xué)家皮埃爾·胡戈寧開著一輛白色的三菱帕杰羅載我到現(xiàn)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(fēng)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(zhì)地。胡戈寧掏出他的手機(jī)。該地區(qū)的雪崩預(yù)報(bào)將我們覆蓋在橙色地區(qū)。他說：“我們處于第三級(jí)”，這是阿爾卑斯山雪崩死亡人數(shù)最多的風(fēng)險(xiǎn)類別，相當(dāng)于美國人所說的“非常嚴(yán)重的程度”。他拿出兩個(gè)雪崩信標(biāo)——即可以向救援人員傳遞我們位置的發(fā)射器——并將它們?cè)O(shè)置為發(fā)送信號(hào)狀態(tài)。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(fā)時(shí)說道。（他是那里的工程師。）“那里太吵了?！爆F(xiàn)在，我們可以邊走邊聽到河水的聲音。在藍(lán)色的天空下，我們的足跡是唯一的痕跡。二十分鐘后，那個(gè)地點(diǎn)出現(xiàn)在眼前：是一個(gè)寬闊且光禿禿的山坡，高達(dá)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?cè)诙觳辉试S住在這里”，胡戈寧說道。兩天前，該地曾發(fā)生過一次自然的滑坡雪崩。我問它是否有危險(xiǎn)?！澳銜?huì)死的”，他說，“沒有機(jī)會(huì)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(jìn)行實(shí)驗(yàn)的完美條件。雪崩研究所使用從直升機(jī)上投放的炸藥，在一個(gè)月內(nèi)引發(fā)了三次雪崩。它們的規(guī)模是如此巨大，以至于摧毀了該研究所的大部分設(shè)備。如果你在最后一次雪崩期間在山上滑雪，你可能會(huì)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。現(xiàn)在，它的臉正在脫落；裂縫有九個(gè)足球場那么寬，有些地方深達(dá)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(huán)境中，你可能會(huì)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(chǎn)生了近兩百英尺高的粉末云。它似乎在進(jìn)行慢動(dòng)作的移動(dòng)，就像干冰在滾動(dòng)，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(shí)驗(yàn)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(yùn)動(dòng)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(gè)小時(shí)才抵達(dá)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(gè)監(jiān)視員就在上面。當(dāng)時(shí)那個(gè)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(dāng)雪傾瀉在山脊上時(shí)，監(jiān)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(gè)實(shí)驗(yàn)摧毀了大部分的森林，當(dāng)?shù)厝藢?duì)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(xù)向前走。在我們的左邊，一個(gè)看起來像蘇聯(lián)人碉堡的建筑從山上探出頭來。它有兩層樓高；在1999年的實(shí)驗(yàn)中，它已經(jīng)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(gè)連續(xù)波雷達(dá)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(jié)構(gòu)上的壓力和速度傳感器。在山坡上，最大的障礙物是一個(gè)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(qū)就像熊出沒之地。威脅幾乎不會(huì)到來，但它卻定義了這個(gè)地方，并賦予它宏偉的氣勢(shì)。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(yuǎn)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(fā)現(xiàn)它不再從我的手指縫中滲出，而是在幾小時(shí)內(nèi)形成了一個(gè)完美的雪球——它在變形。我想到了在延時(shí)攝影中觀察到的植物似乎是帶著動(dòng)物性的目的移動(dòng)的。我想象著這些新落下的雪中的晶體在融結(jié)，發(fā)出噼里啪啦的聲音。

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(dòng)雪崩。這很難讓人感受到它的規(guī)模。胡戈寧把他的雙筒望遠(yuǎn)鏡遞給我。通過望遠(yuǎn)鏡，我看到了齊胸高的雪壘成的巨石。如果沒有望遠(yuǎn)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(jīng)常發(fā)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(xiàng)調(diào)查中，超過一半的越野滑雪者說他們?cè)l(fā)過雪崩；四分之一的人說他們?cè)痪砣胙┍馈＿@說明，將他們與度假區(qū)度假者區(qū)分開來的標(biāo)準(zhǔn)裝備包括一個(gè)信標(biāo)、一個(gè)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(jīng)常被滑成冰道。只是在幾年前，我和一個(gè)朋友去了科羅拉多州的一個(gè)大型滑雪場。有一天，我們?nèi)チ松缴系囊粋€(gè)偏遠(yuǎn)地區(qū)。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(gè)人。雪感覺就像腳下的云；落下時(shí)喚起了我童年時(shí)在樹上跳躍的快樂。在緩慢的彎道上，我認(rèn)識(shí)到這種發(fā)現(xiàn)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(jìn)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(yù)報(bào)。在猶他州雪崩中心（其座右銘是：“讓你站在頂峰上”），預(yù)報(bào)員每天進(jìn)行實(shí)地觀察（“+”表示新雪；“.”表示雪籽；“?”表示深度結(jié)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(fā)風(fēng)成板狀雪崩……這種雪會(huì)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?jí)的危險(xiǎn)等級(jí)；帶有卡通圖標(biāo)的彩色圖表標(biāo)識(shí)了山體的各個(gè)部分——比如說在樹木生長線以上的地區(qū)，或者南坡區(qū)域——是應(yīng)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(dān)心，這樣的圖示會(huì)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(rèn)識(shí)的最有經(jīng)驗(yàn)的越野冒險(xiǎn)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(jìn)行了十多萬米的垂直化學(xué)。在雪地深處，他不僅依靠預(yù)測，還依靠向?qū)В逊欠驳呐袛嗄芰w功于他們。在帶一個(gè)小組出去之前，向?qū)Э赡軙?huì)從斜坡上挖出一個(gè)小圓柱。他將檢查各層，找出弱點(diǎn)，評(píng)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(shí)倒塌，以及如何倒塌。有一次，在一個(gè)看起來很危險(xiǎn)的斜坡上，一個(gè)向?qū)Ц嬖V理查德的團(tuán)隊(duì)，無論他們做什么，他們必須一個(gè)一個(gè)地跟在他的隊(duì)伍右邊。每個(gè)滑雪者依次跟上，小心翼翼地呆在他的右邊。當(dāng)理查德下降時(shí)，在他腳下，在向?qū)У淖阚E左邊幾英尺的地方，有一層雪松動(dòng)了，并在低洼地區(qū)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(gè)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(huì)增加一點(diǎn)樂趣。然而滑雪者卻很難安耐得住?！白罴质强刂莆覀兊挠币环蓊A(yù)報(bào)中如此寫道。在他的一個(gè)學(xué)生死于雪崩之后，蒙大拿州立大學(xué)的教授喬迪·亨德利克斯將他的注意力從地球物理研究轉(zhuǎn)移到了行為科學(xué)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(xiàng)長期的研究中，他讓一大群越野滑雪者用一個(gè)支持全球定位系統(tǒng)的應(yīng)用程序記錄他們的活動(dòng)。他發(fā)現(xiàn)，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(shí)”。)當(dāng)特倫普在2008年出版他的書時(shí)，他報(bào)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(jì)00年代早期，當(dāng)任何數(shù)量的雪的科學(xué)似乎都無法改善結(jié)果時(shí)，對(duì)導(dǎo)致雪崩事故的“人為因素”的研究開始流行。特倫普列出了導(dǎo)致雪崩死亡的六個(gè)常見的“啟發(fā)式陷阱”：做熟悉的事情；致力于一個(gè)目標(biāo)、身份或信仰；跟隨“行家”；在別人觀看時(shí)炫耀；爭搶新鮮雪粉；以及尋求被團(tuán)體接受。瑞士越野滑雪者袖珍指南中充滿了關(guān)于石板和斜坡角度的技術(shù)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(jù)說，新飛行員在第150小時(shí)后最容易發(fā)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(duì)許多滑雪者來說，在完成雪崩規(guī)避課程后，危險(xiǎn)性最高。雪地深處是行為科學(xué)家所謂的“邪惡”的學(xué)習(xí)環(huán)境：它不給你任何負(fù)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(hù)的一個(gè)數(shù)據(jù)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(shí)地考察了一天。滑雪者們遵循一個(gè)有條不紊的嚴(yán)格計(jì)劃行進(jìn)。在預(yù)先確定的地點(diǎn)，該小組評(píng)估了條件；他們挖了一個(gè)雪坑，測試雪柱的強(qiáng)度。他們當(dāng)天的計(jì)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(xiàn)場的坡度，而其中一個(gè)斜坡——他們認(rèn)為不超過29度——實(shí)際上是32度。當(dāng)六個(gè)滑雪者中的第二個(gè)人向下走時(shí)，在上面等待的另外四個(gè)人側(cè)身避開，以便更清楚地看到他的進(jìn)展。山坡上發(fā)生了兩次雪崩，第一次雪崩遠(yuǎn)遠(yuǎn)地觸發(fā)了第二次雪崩，第二個(gè)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(biāo)轉(zhuǎn)向搜索模式，監(jiān)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?nèi)M(jìn)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(bào)告指出了 “持續(xù)的板狀雪崩問題”，它比大多數(shù)報(bào)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(huì)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(gè)晚上，我住在其中一個(gè)旅館里。由于道路已經(jīng)關(guān)閉，廉價(jià)的房間內(nèi)已經(jīng)滿員，當(dāng)時(shí)是四個(gè)人一個(gè)房間。一個(gè)叫比爾的人，四十五歲，住在下鋪。一周前，他經(jīng)歷了一次雪崩——他說，規(guī)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(yīng)付，而且我應(yīng)付過來了”。他意識(shí)到這個(gè)斜坡有可能滑動(dòng)，但他知道如果發(fā)生這種情況該怎么做，所以他還是滑了過去?！拔易隽藥讉€(gè)戰(zhàn)斧式的動(dòng)作”，他說道——在三百英尺的距離內(nèi)翻來覆去，然后站起來。他是不是被嚇到了？他想了想。事實(shí)上，他說道，當(dāng)時(shí)他很平靜。他在床上重復(fù)說著：“可以應(yīng)付，而且我應(yīng)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(dāng)我在瑞士的時(shí)間即將結(jié)束時(shí)，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(xiǎn)地圖。馬格雷特有時(shí)會(huì)用快速大規(guī)模運(yùn)動(dòng)模擬軟件來模擬雪崩風(fēng)險(xiǎn)。“他在使用這個(gè)程序，這對(duì)我而言是一個(gè)巨大的榮譽(yù)”，該軟件的發(fā)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(zhèn)都有基于雪崩危險(xiǎn)地圖的建筑限制。馬格雷特告訴我，“瑞士山區(qū)的每個(gè)人都知道他們的紅區(qū)和藍(lán)區(qū)”。我們驅(qū)車前往達(dá)沃斯外一小時(shí)車程的圣安托尼恩，這是一個(gè)小小的農(nóng)業(yè)村。那里的雪崩威脅如此之大，以至于在暴風(fēng)雨中，居民們?cè)诖蚶磙r(nóng)場時(shí)都要佩戴信標(biāo)。馬格雷特幫助設(shè)計(jì)或批準(zhǔn)了鎮(zhèn)上幾乎所有的雪崩緩解措施：在小學(xué)的上坡一側(cè)有一個(gè)巨大的混凝土楔子；在雪崩爆發(fā)區(qū)高處有大量的鋼梁；房屋建在山的兩側(cè)，這樣雪就會(huì)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(lián)邦政府的一個(gè)代表團(tuán)來到圣安托尼恩，討論重新安置當(dāng)?shù)鼐用竦膯栴}。鎮(zhèn)民們想留下來。馬格雷特說：“瑞士人的心態(tài)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(yùn)輸建筑設(shè)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(qū)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(yīng)急計(jì)劃經(jīng)理和雪崩預(yù)報(bào)員聯(lián)系了馬格雷特。有幾個(gè)街區(qū)位于滑道的沖出區(qū)；這可能是美國最嚴(yán)重的雪崩問題。有什么辦法嗎？即使花費(fèi)數(shù)千萬美元用于減災(zāi)，這些房屋也不可能得到完全的保護(hù)；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(yè)主的產(chǎn)業(yè)買下來，不讓人們?cè)俳ㄐ路?。到目前為止，這在政治上被證明是不可能的；朱諾市已經(jīng)買下了該地區(qū)的幾塊空地，在警告系統(tǒng)和道路保護(hù)協(xié)議方面進(jìn)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(shí)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(huì)開始認(rèn)為雪崩危險(xiǎn)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?cè)跒?zāi)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?yàn)檠┍?。?dāng)我們走在通往城鎮(zhèn)邊緣的路上時(shí)，我們看到食客們?cè)谌诵械郎系淖雷由舷硎苌?。馬格雷特在冬日的陽光下說：“對(duì)于二月的天來說，現(xiàn)在太溫暖了”。自從試驗(yàn)場的團(tuán)隊(duì)進(jìn)行實(shí)驗(yàn)以來，已經(jīng)過去三年時(shí)間了。雪下得還不夠多。