Tree well immersion (SIS) and deep powder snow suffocation survival¶

Kanga igi ** (tabi ** Imu Imubọmi Snow / SIS *** eewu) jẹ ofo ti o farapamọ, ti ko ni isọdọkan ti egbon alaimuṣinṣin, awọn ẹka ti o ni idorikodo kekere, ati afẹfẹ yika ẹhin igi conifer lẹhin yinyin nla. Nigba ti skier tabi snowboarder mu eti kan nitosi igi ti o ni ayeraye ti o si kọkọ kọkọ sinu ọfin ti o farapamọ yii, aṣọ-ikele ti o wa ni ayika ti erupẹ yinyin ti o gbẹ ṣubu sinu inu bi iyanrin iyara lakoko ti awọn skis tabi snowboard wọn sinu awọn ẹka ti o wa loke, ti o di wọn ni isalẹ ni okunkun lapapọ. Gẹgẹbi Ile-iṣẹ Avalanche Avalanche Northwest (NWAC) ati National Ski Areas Association (NSAA) ni Orilẹ Amẹrika ati Kanada, awọn iroyin Imudanu Snow ti kii ṣe avalanche fun aijọju ** 20 si 25 ogorun gbogbo awọn apaniyan awọn ere idaraya igba otutu ti o wa ni opin ** lakoko awọn akoko lulú jin, ati ni awọn adanwo iwalaaye, ** 90 ogorun ti awọn oluyọọda kan ko le gbe ara wọn silẹ ni ita ti awọn oluyọọda.

Itọsọna yii rin awọn skiers, snowboarders, snowshoers, ati backcountry ẹlẹṣin nipasẹ ohun ti lati se ni akọkọ 5 aaya ti o ba ti o ba ṣubu sinu kan igi daradara tabi jin lulú apo, idi ti thrashing fa lẹsẹkẹsẹ egbon compaction ati suffocation, bawo ni awọn alabaṣepọ gbọdọ oju eefin ni nâa lati isalẹ ẹgbẹ dipo ju sokale lori oke ti iho, ati bi lati se igi daradara ẹgẹ lori powder ọjọ.

Ṣe eyi ni bayi¶

1. **Ti o ba ṣubu si ọna igi daradara: jẹ ki awọn ọpa rẹ lọ ki o si mu ẹhin igi tabi awọn ẹka lẹsẹkẹsẹ. Bi o ṣe ṣubu, na ọwọ mejeeji lati famọra ẹhin igi ti o nipọn tabi awọn ẹka oke ti o nipọn lati da ori ati àyà rẹ duro lati yiyi pada sinu ofo ni isalẹ.
2. Ti o ba de ni ilodi si ni egbon: MAA ṢE fọ, tapa, tabi yi ẹsẹ rẹ lọ. Ni alaimuṣinṣin, egbon eruku ti ko ni itunnu, tiraka n ṣe gangan bi ẹrọ gbigbọn simenti ẹrọ: gbogbo tapa kọlu awọn ọgọọgọrun kilo ti egbon kuro ni awọn ẹka loke ati ki o di ṣinṣin ni ayika àyà ati oju rẹ, ti o jinle jinle. Di ẹsẹ rẹ lẹsẹkẹsẹ.
3. **Ṣẹda apo afẹfẹ ti o nmi ni iwaju ẹnu ati imu rẹ.
4. ** Duro ni idakẹjẹ, simi laiyara, ki o si fun súfèé rẹ (ti o ba wa nitosi ẹnu rẹ)** Ibanujẹ hyperventilation yarayara n gba apo kekere ti atẹgun rẹ ati yo yinyin ni ayika oju rẹ pẹlu ẹmi gbona, eyiti o tun pada sinu didan yinyin ti afẹfẹ (”boju yinyin”). Ti o ba le de ẹhin igi pẹlu ọwọ kan, dimu mọ ọ ki o ma ba jinle, ki o duro de alabaṣepọ rẹ.
5. If you are the partner outside: NEVER step on the rim of the hole or pull the victim straight up by their boots/skis. Stepping onto the top edge of the tree well collapses a ton of snow directly onto your friend's head, and yanking upward on wedged skis or a snowboard only drives their head deeper into the pit.
6. Call Ski Patrol or emergency services immediately and dig horizontally from the side or downhill toward their head. Shout for nearby riders to help, call the resort Ski Patrol emergency number (or call your local emergency number: 911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom; see our pajawiri awọn nọmba directory), locate the victim's head beneath the boots, and tunnel inward from the side/downhill to clear an airway around their face before unclipping their bindings.

Immediate survival and partner rescue decision flow¶

Whether you are the rider falling into a tree well or the partner who just saw your friend vanish under the boughs, follow this sequence immediately.

flowchart TD
    A["Rider Falls Near Conifer Tree or Deep Powder Pocket"] --> B{"Which Role Are You In Right Now?"}
    B -->|"I Am the Rider Falling Into the Tree Well"| C["Drop Ski Poles Immediately and Grab Tree Trunk or Heavy Branches"]
    C --> D["Stop All Leg Thrashing and Kicking to Prevent Snow Funnel Collapse"]
    D --> E["Cup Hands or Forearm Over Mouth & Nose to Carve a Breathing Pocket"]
    E --> F["Hold Onto Trunk if Reachable, Breathe Slowly, and Wait for Partner Excavation"]
    B -->|"I Am the Partner Outside Who Saw Rider Disappear"| G["Keep Strict Visual Fix on Exact Tree (Mark With Upright Skis or Pole Outside Rim)"]
    G --> H["Call Resort Ski Patrol Emergency Number / 911 / 112 and Yell for Nearby Riders"]
    H --> I["DO NOT Step on Top Lip of Hole and DO NOT Pull Up on Victim's Skis or Snowboard"]
    I --> J["Probe Gently With Hand Along Trunk to Locate Victim's Head and Chest Depth"]
    J --> K["Tunnel Inward Horizontally From the Downhill Side Directly to Victim's Face"]
    K --> L["Clear Snow From Mouth and Nose First, Then Release Bindings and Extract"]

How a tree well forms and why conifers look safe from above¶

Many skiers and snowboarders assume that if there is 2 meters (6.5 feet) of fresh snow on the open ski run, the snow stays flat right up to the trunk of every pine, fir, spruce, or hemlock tree. In reality, low-hanging evergreen branches act like a giant umbrella:

1. The branch umbrella: As meters of snow fall over the winter, the wide, downward-sloping lower branches of fir, spruce, hemlock, and cedar trees catch the falling snow and prevent it from reaching the ground around the base of the trunk.
2. The hidden 2-to-3-meter (6-to-10-foot) void: Directly beneath the bottom branches sits a deep, conical pit of air, tangled dead branches, and loose, uncompacted feathers of dry snow extending all the way down to the bare forest dirt or rocks, even when the surrounding snowpack is 3 meters (10 feet) deep.
3. The visual illusion: From 5 meters (16 feet) uphill, the snow-covered outer tips of the tree branches blend smoothly into the smooth powder slope. A rider carving a turn too close to the outer branch skirt ("skirting the tree") breaks through the thin crust of branch tips and drops straight into the hidden vertical shaft headfirst.

Ilana iwalaaye ni igbese-nipasẹ-igbesẹ ti O ba ṣubu sinu igi daradara¶

Ti o ba padanu iṣakoso tabi yẹ eti kan ki o ni rilara pe o n gbe ori akọkọ labẹ awọn ẹka igi conifer, awọn iṣe rẹ ni akọkọ **3 si 5 iṣẹju-aaya *** ṣaaju ki egbon naa pinnu ipinnu iwalaaye rẹ.

Step 1: Fight to stay upright or arrest your slide on the trunk¶

• Never wear ski pole wrist straps in the trees: If your hands are looped inside pole straps when you fall into a tree well, the poles catch on branches and pin your arms backward over your head so you cannot reach your face to clear snow. When skiing glades or off-piste powder, always hold your pole grips without putting your hands through the wrist loops.
• Hug the trunk or thick inner branches: As you crash through the outer boughs, lunge with both arms for the solid wooden tree trunk or thick inner limbs and wrap your arms or legs around them like a climbing koala. Even if your skis drop below you, keeping your head and shoulders hooked over a branch above the pit saves your life.
• Try to roll onto your back or side (tuck and roll): If you are pitching over your handlebars in deep open powder away from a tree, tuck your chin and roll onto your side or back so your face points toward the sky rather than burying face-down.

Step 2: Stop all kicking and create your breathing space¶

If you are already inverted inside the tree well and snow is cascading around you:

1. Freeze your legs immediately: Every human instinct screams at you to kick your legs and try to swim upward. Resist that urge completely. Because your skis or snowboard are 150 to 185 centimeters (5 to 6 feet) long and locked inside stiff branches above you, kicking your legs cannot move you upward, it only shakes the tree canopy and packs hundreds of kilograms of loose snow tightly down around your head and ribcage.
2. Lock an arm across your face ("The Boxer Guard"): Bring one or both hands immediately to your face. Sweep a hollow cavity around your mouth and nose, and hold your forearm or cupped hands a few centimeters in front of your mouth so settling snow stops against your arm instead of pressing flat against your lips and nostrils.
3. Spit out any snow in your mouth before inhaling: If snow entered your mouth during the tumble, spit it out or sweep it out with a gloved finger before taking a deep gasp of air so you do not aspirate powder into your windpipe.
4. Expand your chest as the snow settles: Take a deep breath and hold your elbows slightly outward for the first 10 seconds while the loose snow settles around your torso; this leaves a important 2-centimeter (1-inch) expansion gap around your ribcage so you can still breathe in and out once the snow stops moving.

Step 3: Can you ever self-extricate if you are completely alone?¶

In landmark field tests conducted by tree-well researcher Paul Baugher (Northwest Avalanche Center), 90 percent of test subjects placed into real tree wells could not get out on their own. For the 10 percent who managed to self-rescue, or if you broke the #1 rule of powder skiing and rode into the trees alone, here is the only technique that ever works:

• Only move with slow, deliberate, millimeter movements: Never jerk or thrash.
• Keep one hand anchored on the solid tree trunk or a thick root/branch: Use the tree trunk itself as your only solid ladder rung.
• Do NOT try to push against the loose snow wall: Instead of trying to climb up the snow, see if you can slowly reach up along your own leg to pop your ski binding heel piece or unbuckle your snowboard ankle straps, only if your upper body is already wedged securely against the tree trunk so releasing your feet will not cause your body to slide 1 meter (3 feet) deeper down the bottomless shaft.
• Check if you can wriggle further DOWN or SIDEWAYS along the bare trunk: On steep slopes, the downhill side of the tree well often has a thinner wall of branches and snow than the uphill side. Sometimes a trapped rider can pull themselves against the bare bark of the trunk and push sideways out through the lower downhill skirt of branches rather than going up.

Partner rescue: how to dig someone out of a tree well without killing them¶

Over 80 percent of tree well victims die simply because their partners kept skiing all the way down to the bottom of the chairlift, waited 15 minutes at the lift line wondering "Where is Dave?", and then rode the chairlift back up to start looking, by which time 30 minutes had elapsed and the victim had already suffocated.

When you ride within visual and voice contact of your partner and see them tumble into a tree well (or see a single ski tip, snowboard base, or glove sticking out beneath a conifer tree), you have under 15 minutes to get air to their face.

CRITICAL PARTNER EXCAVATION RULES FOR A TREE WELL:
1. NEVER step onto the top rim of the snow cone around the tree (collapses snow onto the victim's face).
2. NEVER grab the victim's boots, skis, or snowboard and yank upward (drives their head deeper and breaks legs/spine).
3. ALWAYS approach from the DOWNHILL or SIDE of the tree and tunnel INWARD HORIZONTALLY straight to the victim's head.

Step-by-step partner excavation protocol¶

1. Mark the tree and call for backup immediately:
   • Plant your own skis or poles upright in the open snow 3 meters (10 feet) uphill of the tree so approaching Ski Patrol or other riders can spot the exact tree instantly (in a dense forest of 500 identical fir trees, taking your eyes off the tree for ten seconds can make you lose the spot).
   • Yell loudly "HELP. SKIER IN A TREE WELL HERE." to flag down passing riders on the run.
   • Have a second person (or use your speakerphone while moving) call the resort's Ski Patrol Emergency Direct Line (program it into your phone before riding; it is printed on every paper trail map and lift tower) or dial 911 / 112 / 999 with the exact trail name and lift tower number.
2. Stabilize the victim's feet so they do not slide deeper:
   • If you can see the victim's boots, skis, or snowboard tangled in the upper branches, do not pull them up, and do not unclip their bindings yet if those snagged skis are the only thing holding their body from dropping another meter down into the bottom of the pit.
   • Dipo, ti olugbala keji ba wa, jẹ ki wọn rọra mu tabi tẹ bata bata/ẹsẹ ẹni ti olufaragba naa duro ni aaye ki olufaragba naa ko le yo jinle lakoko ti o wa si ori wọn.
3. ** Ṣe apejọ shovel avalanche rẹ ati oju eefin ni lati IPA Isàlẹ ***:
   • Wo igun ti awọn ẹsẹ ẹni ti o jiya lati ṣe iṣiro ni pato ibi ti ori ati àyà wọn ti wa ni isinmi si ẹhin igi (nigbagbogbo 1 si 1.5 mita / 3 si 5 ẹsẹ ni isalẹ awọn bata orunkun wọn).
   • Igbesẹ ni ayika si ** ẹgbẹ isalẹ ** (tabi apa isalẹ) ti igi daradara, duro patapata kuro ni aaye egbon oke.
   • Lo aluminiomu alumọni kan ti o le kọlu ** shovel owusuwusu *** (tabi ọwọ rẹ / snowboard ti o ko ba ni shovel) lati * ge ẹnu-ọna petele kan taara sinu awọn ẹka isalẹ ati odi yinyin ** ni ipele ti ori ẹni ti o jiya, fifọ egbon si isalẹ lati igi nitorina ko le rọra pada sinu.
4. **Pa ọna atẹgun ni ayika ẹnu ati imu NI KỌKỌ ***:
   • Ni akoko ti ọwọ ibọwọ rẹ ba kan ibori, jaketi, tabi ejika ẹni ti o jiya, dawọ lilo abẹfẹlẹ irin ti o wa nitosi ori wọn ki o ma ba lu oju wọn.
   • Yọ yinyin kuro ni ẹnu wọn, imu, ati àyà pẹlu ọwọ rẹ, fa eyikeyi ọrùn gaiter tabi sikafu ti o ni egbon ti o kun, ki o si yọ ohun elo egbon eyikeyi kuro ni ẹnu wọn.
   • Ṣayẹwo lẹsẹkẹsẹ ti wọn ba mọ ati mimi:
     • **Ti wọn ba wa ni mimọ ati mimi ***: Jẹ ki ọna atẹgun wọn ṣii, fi wọn da wọn loju, fa yẹrẹ petele ni ayika torso wọn ki àyà wọn le faagun larọwọto, ati pe * lẹhinna * tu awọn abuda ski wọn tabi awọn okun snowboard loke ki o le rọra rọra jade nipasẹ eefin ẹgbẹ rẹ.
     • ** Ti wọn ko ba dahun ati pe wọn ko ni mimi (tabi gaasi nikan) ***: Fa wọn jade sori pẹpẹ ti o tẹ pẹlẹbẹ lẹsẹkẹsẹ lakoko ti o daabobo ọrùn wọn, ṣii ọna atẹgun, fun ** 5 awọn ẹmi igbala ibẹrẹ akọkọ ** (nitori igi daradara imudani ọkan ọkan jẹ ṣẹlẹ nipasẹ ** hypoxia / asphyxiation ***, awọn ẹmi igbala pọ pẹlu awọn titẹ àyà jẹ pataki ti o ko ba le fun ni ikẹkọ; ọwọ-nikan CPR ni 100 si 120 compressions fun iṣẹju kan lẹsẹkẹsẹ) ati tẹsiwaju titi Ski Patrol yoo fi de pẹlu atẹgun ati AED kan.

Bii o ṣe le ṣe idiwọ igi daradara ati awọn ajalu immersion yinyin jinna¶

Gbogbo igi kan ṣoṣo ti o ku ni o jẹ idilọwọ nipasẹ titẹle awọn ofin ọjọ-iyẹfun marun ti kii ṣe idunadura ti a fọwọsi nipasẹ Ẹgbẹ Awọn Agbegbe Ski ti Orilẹ-ede (deepsnowsafety.org) ati MountainSafety.info:

• **1. Jeki alabaṣepọ rẹ ni oju wiwo taara ni gbogbo igba (Kii ṣe "pade ni isalẹ ti igbega") ***: Gigun "pẹlu awọn ọrẹ" ko dara ti o ba pin si oke ti ṣiṣe ati pade ni ijoko ijoko iṣẹju mẹwa lẹhinna. Ninu awọn igi tabi ni awọn ọjọ lulú ti o jinlẹ, gùn ni ** awọn aaye fifo kukuru kukuru ** tọju alabaṣepọ rẹ laarin laini taara ti oju (tabi ipe ohun nigbagbogbo ati idahun ni gbogbo iṣẹju-aaya 15) titi ti iwọ mejeeji yoo fi jade kuro ninu awọn igi.
• **2. Mu ọwọ rẹ kuro ni awọn okun ọwọ ọwọ ski ṣaaju ki o to wọle eyikeyi glade tabi pipa-piste run ***: Awọn ọpa ọpa yi awọn ọpa ski rẹ pada si awọn ìdákọró ti o fi ọwọ rẹ si ori ori rẹ ni igi kan daradara ati yọ awọn atampako / ejika kuro lori awọn ẹka. Jẹ ki awọn ọpa rẹ lọ lẹsẹkẹsẹ ti o padanu iwọntunwọnsi.
• **3. Wọ fèrè iwalaaye ti ko ni ariwo ti a ge si ọtun lẹgbẹẹ agbọn rẹ ***: Teepu tabi gige súfèé pilasitik ti ko ni iwọn decibel 120 (gẹgẹbi Fox 40) sori idalẹnu jaketi rẹ tabi apoeyin sternum okun kan 10 centimeters (4 inches) lati ẹnu rẹ ki o le de ọdọ rẹ pẹlu àyà rẹ paapaa ti àyà rẹ pin.
• **4. Gbe ohun avalanche transceiver (Beakoni), collapsible irin shovel, ati iwadi, ani IN-BOUNDS on jin powder ọjọ ***: Ọpọlọpọ awọn skiers fi wọn owusuwusu Beacon ati shovel ninu awọn ọkọ ayọkẹlẹ nigba ti sikiini inu awọn ohun asegbeyin ti aala. Ni eyikeyi ọjọ pẹlu 30+ centimeters (12+ inches) ti egbon titun tabi nigbati awọn igbadun igi ibi isinmi sikiini, wọ transceiver oni-nọmba oni nọmba 3 eriali ti nṣiṣe lọwọ (457 kHz) ni ipo Firanṣẹ ati gbe idii kan pẹlu shovel irin kan. Alabaṣepọ pẹlu transceiver ati shovel le ṣe afihan ati ki o yọ ẹlẹṣin patapata ti o sin labẹ igi ni ** 3 iṣẹju ** dipo lilo 20 iṣẹju lafaimo iru igi ti wọn ṣubu labẹ.
• **5. Fun awọn igi conifer ni aaye ti o gbooro, maṣe ge awọn iyipada labẹ laini drip ẹka ẹka ***: Duro ni awọn ọna funfun ti o ṣii laarin awọn igi ju ki o famọra awọn ogbologbo, ṣakoso iyara rẹ ki o le da duro ṣaaju kọlu awọn idiwọ, ki o ṣọra fun awọn oke kekere 1-mita (ẹsẹ 3) “ọmọ” evergreen ti o n jade kuro ninu egbon, ade igi alawọ ewe kekere kan ti 6 gangan jẹ a omiran pamọ daradara labẹ awọn egbon dada. Fun awọn pajawiri oke igba otutu ti o jọmọ, ka wa Sikiini, Snowboarding, ati awọn ijamba ite, avalanches, ati aginju hypothermia ati tutu awọn itọsọna.

Awọn ibeere ti a beere nigbagbogbo¶

Awọn orisun ṣayẹwo¶

• Ile-iṣẹ Avalanche Northwest (NWAC, United States) & Paul Baugher (Alakoso Cristal Mountain Ski Patrol): * Igi Daradara ati Aabo Imọlẹ Jin (deepsnowsafety.org)*, Igi Igi Imudaniloju Daradara Immersion Iwadi ati Awọn Ilana Excavation Alabaṣepọ.
• Ẹgbẹ Awọn Agbegbe Ski ti Orilẹ-ede (NSAA, Amẹrika) ati Ẹgbẹ Awọn agbegbe Ski Iwọ-oorun Iwọ-oorun ti Ilu Kanada (CWSAA, Kanada): Awọn Itọsọna Idena Idena Ilẹ-owu ti Ilẹ-yinyin ati Imudanu Immersion (SIS).
• International Commission for Alpine Rescue (ICAR / CISA-IKAR, International / Switzerland) ati Aginjun Medical Society (WMS, United States): isẹgun Itọnisọna fun Idena ati isakoso ti owusuwusu ati Non-Avalanche Snow olufaragba.
• Avalanche Canada ati Canadian Ski Patrol (Canada): Igi Igi, Imulẹ Powder Immersion, ati Awọn Ilana Isọdọtun Isinku Asphyxial.
• European Resuscitation Council (ERC, European Union) ati American Heart Association (AHA, United States): Awọn ipo pataki ti Resuscitation, Lairotẹlẹ Hypothermia ati Asphyxial Arrest Ventilation Protocols.

Jẹmọ awọn itọsọna¶

• Sikiini, snowboarding, ati awọn ijamba ite
• Avalanches
• Aginju hypothermia ati tutu
• Ọwọ-nikan CPR