Vulkanski plinski oblaki, leni oblaki in limnični izbruhi¶

Številke za klic v sili se razlikujejo glede na državo. Ta stran uporablja 911, številko za Združene države in Kanado. Mnoge druge države uporabljajo 112, 999 ali drugo številko. Poiščite številko za svojo državo.

Volcanic and geothermal zones release invisible, life-threatening gases even when no explosive ash eruption is occurring, while deep volcanic crater lakes can suddenly overturn and release suffocating clouds of pure carbon dioxide ($CO_2$) in a rare disaster known as a limnic eruption (lake overturn). Unlike volcanic ash or wildfire smoke that rises high into the sky, the three deadliest volcanic and geothermal gases, carbon dioxide ($CO_2$), hydrogen sulfide ($H_2S$), and sulfur dioxide ($SO_2$), are significantly heavier than normal air ($1.2\text{ to }2.2\text{ times}$ denser than dry air). Instead of floating upward, these gases pour downhill along the ground like an invisible liquid river, pooling inside valleys, volcanic craters, basements, excavations, snow caves, and shoreline depressions. At the same time, when molten coastal lava enters the ocean, it boils seawater into a white plume of concentrated hydrochloric acid ($HCl$) mist and microscopic volcanic glass shards called laze (lava haze). Survival depends entirely on recognizing low-ground gas traps, climbing immediately uphill and crosswind, and understanding why a single breath of $10\text{ to }30\text{ percent}$ carbon dioxide or $1,000\text{ ppm}$ hydrogen sulfide causes instant loss of consciousness ("knockdown").

Never climb down into a depression, basement, or snow hole to rescue a collapsed hiker or animal

Because carbon dioxide ($CO_2$, specific gravity $1.52$) and hydrogen sulfide ($H_2S$, specific gravity $1.19$) are heavier than air, they form an invisible, razor-sharp "gas lake" hugging the lowest ground. Frequently, a dog, bird, or child (whose head is closer to the ground) collapses first inside a volcanic depression, geothermal hot spring basin, or crater trench; when an adult bends down or climbs into the depression to pick them up, the rescuer inhales a lungful of $15\text{ to }30\text{ percent }CO_2$ or $H_2S$, loses consciousness in 1 to 3 breaths, and dies right beside the first victim. If you see dead birds, dead small mammals, or a collapsed person in a low-lying volcanic or crater-lake area, hold your breath immediately, DO NOT bend down, and scramble straight uphill to higher ground before calling emergency rescuers with self-contained breathing apparatus (SCBA).

Naredi to zdaj¶

Climb straight uphill and move crosswind (at a 90-degree angle to the wind) immediately. Heavy volcanic gases ($CO_2$, $H_2S$, $SO_2$) flow downhill like water through ravines, stream gullies, and valleys, while wind pushes plumes of sulfur dioxide ($SO_2$) and coastal hydrochloric acid lava haze (laze) downwind. Never try to outrun a gas cloud by running downhill along a valley road: scramble straight up the nearest ridge, hill, or upper floor of a building above the pooling gas layer and move perpendicular to the wind direction.
Watch the ground for "Nature's Gas Detector": dead birds, dead insects, dead livestock, or a sudden stalled car engine. Carbon dioxide is completely invisible and completely odorless. If you are walking or driving near a volcanic flank, geothermal fumarole field, or crater lake and suddenly spot freshly dead birds, mice, frogs, or insects lying on the ground with no marks on them, or if your combustion car engine suddenly sputters and stalls (because $CO_2$ has displaced atmospheric oxygen below the $13\text{ to }15\text{ percent}$ needed for engine combustion), you have entered a lethal $CO_2$ pocket. Hold your breath and run uphill immediately.
Never trust your nose around "rotten egg" hydrogen sulfide ($H_2S$) gas: olfactory paralysis happens in seconds. At low, harmless concentrations ($0.01\text{ to }10\text{ ppm}$), hydrogen sulfide smells strongly like rotten eggs. However, once $H_2S$ reaches life-threatening levels (above $100\text{ to }150\text{ ppm}$), it paralyzes the olfactory nerve in your nose within 2 to 15 seconds, making the smell completely disappear so you fatally assume the air has cleared. If you smell strong rotten eggs near a hot spring, mud pot, or fumarole and the smell suddenly vanishes while your eyes sting or you feel dizzy, climb uphill into the wind immediately.
Breathe through a wet cloth or baking-soda-soaked shirt ONLY for acid gases ($SO_2$ and $HCl$ laze); understand that NO cloth or filter mask works against $CO_2$. If caught in a choking cloud of sulfur dioxide ($SO_2$) or coastal hydrochloric acid laze ($HCl$), cover your nose and mouth with a cloth soaked in water (or better yet, water mixed with a spoonful of baking soda [sodium bicarbonate], which neutralizes acid gases on contact) and close your eyes as much as possible. However, remember that no wet cloth, N95 mask, or P100 chemical cartridge respirator can protect you from Carbon Dioxide ($CO_2$) asphyxiation: $CO_2$ displaces oxygen from the air, so only climbing to fresh uphill air or breathing bottled oxygen/SCBA air will keep you alive.
Evacuate volcanic crater lake shores and valleys immediately if the lake water bubbles, turns reddish-brown, or rumbles (Limnic Eruption). If you live or travel near a deep tropical volcanic crater lake (maar lake) and notice a sudden underwater rumble, a fountain or tsunami wave forming in the middle of the lake without wind, or the lake water turning cloudy rust-brown (caused by deep iron-rich $CO_2$-saturated water rising to the surface), a limnic eruption has begun. Hundreds of thousands of tons of heavier-than-air $CO_2$ gas are about to pour over the crater rim and race down the surrounding river valleys at 20 to 50 kilometers per hour (12 to 30 miles per hour). Climb at least 50 to 100 vertical meters (165 to 330 feet) up the valley ridges immediately.
Administer high-flow oxygen or CPR on high ground and flush acid-burned eyes with clean water for 15 minutes. Once a gas-exposed victim has been safely reached on ventilated high ground (never enter the low gas pocket yourself without SCBA), call your local emergency number (911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom, or see all številke za klic v sili). If they are unconscious and not breathing normally, start CPR immediately (use a pocket mask or hands-only chest compressions if $H_2S$ or acid gas was inhaled). If they are wheezing from $SO_2$, vog, or laze, help them use their prescribed albuterol/salbutamol bronchodilator inhaler and flush burning eyes with clean running water for 15 minutes.

Volcanic gas, laze, and limnic eruption survival decision tree¶

Use this field triage flowchart to identify which volcanic gas hazard you are facing and execute the exact survival maneuver.

flowchart TD
    Start["Volcanic / Geothermal / Crater Lake Gas Emergency:<br/>Fumarole Field, Coastal Lava Ocean Entry, or Crater Lake"] --> HazardType{"What type of gas or plume<br/>environment are you in?"}

    HazardType -->|"1. Low Valley, Crater Floor, Basement, Snow Pit,<br/>or Crater Lake Turning Brown / Bubbling"| HeavyGas["SUSPECTED CO2 (Limnic Eruption / Mazuku) OR High H2S:<br/>1. DO NOT bend down or enter low depressions<br/>2. Hold breath if dizzy or dead birds/animals seen<br/>3. Climb IMMEDIATELY UPHILL (>= 30 to 100 m vertical)<br/>   (Filter masks & wet cloths do NOT stop CO2 asphyxiation)"]

    HazardType -->|"2. Sharp Choking 'Burnt Match' Smell,<br/>Stinging Eyes/Throat, or Hazy Vog Plume"| SO2Vog["SULFUR DIOXIDE (SO2) / VOLCANIC SMOG (VOG):<br/>1. Move UPHILL and CROSSWIND (90 degrees to wind)<br/>2. Breathe through wet cloth (ideally soaked in baking soda water)<br/>   or use P100 + Acid Gas cartridge respirator<br/>3. If indoors: Close all windows/doors, turn off A/C fresh-air intake,<br/>   and use asthma rescue inhaler if wheezing"]

    HazardType -->|"3. White Steam-Like Plume Where Molten Lava<br/>Enters Ocean Seawater"| LazePlume["HYDROCHLORIC ACID 'LAZE' (Lava Haze + Glass Shards):<br/>1. NEVER stand downwind of an ocean lava entry point<br/>2. Move immediately UPWIND / CROSSWIND at least 500+ meters<br/>3. Do NOT rub eyes (microscopic Pele's glass shards scratch corneas)<br/>4. Flush eyes and skin with generous clean water for 15 minutes"]

    HeavyGas --> CasualtyCheck{"Has someone collapsed in the gas zone?"}
    SO2Vog --> CasualtyCheck
    LazePlume --> CasualtyCheck

    CasualtyCheck -->|"Casualty still inside low gas pit/depression"| WaitSCBA["STOP: Do NOT enter the low gas pocket without SCBA air tank<br/>(60% of confined-space/volcanic gas deaths are would-be rescuers)<br/>Call 911 / 112 / 999 for Fire Rescue SCBA extraction"]

    CasualtyCheck -->|"Casualty on ventilated high ground"| FirstAidHigh["1. Check breathing: Start CPR if unresponsive and not breathing<br/>2. Place unconscious breathing casualty in Lateral Recovery Position<br/>3. Flush eyes with plain water; give bronchodilator for SO2/Laze bronchospasm<br/>4. Monitor 24 to 48 hrs in hospital for Delayed Pulmonary Edema"]

Comparing the 5 lethal volcanic and crater-lake gas hazards¶

Every volcanic gas has a distinct molecular weight, smell, and killing mechanism. Use this USGS and IVHHN (International Volcanic Health Hazard Network) clinical table to distinguish them.

Gas / Plume Name & Formula	Specific Gravity (vs. Normal Air = $1.00$)	Smell, Color, and Warning Signs	Lethal Concentration & Mechanism of Death	What Protective Gear Works?
1. Carbon Dioxide ($CO_2$) (Limnic Eruptions, "Mazuku" Death Pockets, Cold Trap Seeps)	$1.52\text{x}$ heavier than air (Hugs ground, fills valleys, trenches, basements, and tree wells)	Colorless and 100% ODORLESS. High concentrations ($>5\%$) taste slightly sour/carbonated on the tongue and sting the nostrils like soda fizz.	$7\%\text{ to }10\%$ ($70,000\text{ to }100,000\text{ ppm}$): Dizziness, pounding headache, gasping breath (hypercapnic drive), unconsciousness in minutes. $15\%\text{ to }30\%$: Instant knockdown in 1 to 3 breaths, convulsions, coma, and asphyxiation death within minutes.	ONLY Self-Contained Breathing Apparatus (SCBA) air tank or climbing uphill to fresh air. (Gas masks, N95s, and wet cloths are 100% useless* against $CO_2$).*
2. Hydrogen Sulfide ($H_2S$) (Geothermal Hot Springs, Mud Pots, Solfataras)	$1,19\text{x}$ težji od zraka (Bazeni v termalnih bazenih, kopališčih in požiralnikih)	Brezbarven. Močan vonj po "gnilih jajcih" pri nizkih ravneh ($0,01\text{ do }30\text{ ppm}$), ki mu sledi nenadna popolna izguba vonja nad $100\text{ do }150\text{ ppm}$ (vohalna paraliza).	$50\text{ do }100\text{ ppm}$: Hudo draženje oči (keratokonjunktivitis "plinskega očesa") in kašelj. $500\text{ do }1.000+\text{ ppm}$: Takojšnji "knockdown" v 1 vdihu: blokira citokrom c oksidazo v celičnih mitohondrijih (identično zastrupitvi s cianidom) in paralizira dihalni center možganskega debla.	SCBA rezervoar za zrak za visoke/neznane ravni; beg navkreber v veter.
3. Žveplov dioksid ($SO_2$) in Vog (aktivni vulkanski žarki, kraterji, razpoke)	$2,26\text{x}$ težji od zraka, ko je hladen (Dvigne se v vročih termalnih oblakih, nato pa se spusti v doline z vetrom)	Brezbarven plin (ali meglen modro-siv Vog sulfatni aerosol). Oster, oster, zadušljiv vonj po "zažgani vžigalici" ali zažganem ognjemetu pri samo $1\text{ do }3\text{ ppm}$.	$5\text{ do }20\text{ ppm}$: Takojšen močan kašelj, pekoč občutek v grlu in hud usoden bronhospazem pri ljudeh z astmo/KOPB. $100+\text{ ppm}$: Reagira s pljučno vlago in tvori žveplovo in žveplovo kislino, kar povzroča kemične opekline dihalnih poti in zapozneli pljučni edem.	NIOSH/EN respirator s kartušo za kisle pline + filter za delce P100; rezerva v sili: mokra krpa, namočena v vodo + soda bikarbona.
4. Klorovodikova kislina "Laze" ($HCl$ + steklo) (vstopni oblaki lave v obalnem oceanu)	Gosta bela meglica, podobna pari, ki jo vodoravno piha morski vetrič vzdolž obale	Svetlo bel valovit oblak, ki je videti kot neškodljiva para, z ostrim ostrim vonjem po belilu/kislini in drobnim zrnatim prahom.	Koncentrirane kapljice klorovodikove kisline ($HCl$) ($\text{pH } 1,5\text{ do }2,0$, tako jedke kot želodčna kislina ali baterijska kislina), pomešane z mikroskopskimi *iglami iz vulkanskega stekla (delci Pelejevih las)*. Povzroča akutne kemične opekline pljuč, laringealni spazem in odrgnine roženice.	Kislin plin + respirator P100 + zaprta očala proti brizganju kemikalij; nikoli ne stojite ob vetru od vstopa v oceansko lavo.
5. Vodikov fluorid ($HF$) (eksplozivni prameni pepela in razplinjena magma)	0,70 $ kot monomer, vendar tvori kapljice težke kisle megle in prekrije padajoči vulkanski pepel	Brezbarven dimni plin/megla z dražečim kislim vonjem; prekriva travo na pašnikih in onesnažuje cisterne za deževnico.	Prodira v kožo in pljuča, da veže kalcij in magnezij v krvi, kar povzroči hudo hipokalciemijo, hipomagneziemijo, fluorozo in smrtonosno ventrikularno fibrilacijo, srčni zastoj (ubije pašne ovce/govedo in onesnaži pitno vodo).	Respirator s kislim plinom; odklopite strešne žlebove za zbiranje deževnice, preden preidejo oblaki pepela/plina; zdravite kožne opekline s kalcijevim glukonatnim gelom.

Deep dive 1: Limnic eruptions (Crater lake overturns) and "Mazuku" death pockets¶

A limnic eruption (also called a lake overturn) is one of the rarest and most terrifying natural disasters on Earth. In 1984 at Lake Monoun (killing 37 people) and on August 21, 1986 at Lake Nyos in Cameroon, a deep volcanic crater lake suddenly erupted without a drop of lava, releasing up to 300,000 to 1.6 million metric tons of pure dissolved carbon dioxide ($CO_2$) gas. A silent, invisible cloud of $CO_2$ 50 meters (165 feet) thick spilled over the crater rim and flowed down the surrounding river valleys at 20 to 50 kilometers per hour (12 to 30 miles per hour), extinguishing every cooking fire, stalling vehicles, and silently suffocating 1,746 people and over 3,500 cattle in their sleep up to 25 kilometers (15 miles) away.

How a limnic eruption works (The "Champagne Bottle" Lake Mechanism)¶

Volcanic $CO_2$ injection at the bottom of a deep, unmixed lake: Magma sitting kilometers beneath an extinct or dormant volcanic crater (maar) continuously leaks carbon dioxide gas up through the lake bed. In most temperate lakes, seasonal winter cooling causes the surface water to sink and mix the lake every year (holomictic lakes), releasing harmless small amounts of gas. However, in deep tropical lakes like Lake Nyos, Lake Monoun (Cameroon), and Lake Kivu ( located on the border of the Democratic Republic of the Congo and Rwanda, holding roughly $300\text{ cubic kilometers}$ of dissolved $CO_2$ and $60\text{ cubic kilometers}$ of methane), the warm top layer of water never cools enough to sink (meromictic stratification).
Hidrostatični tlak ujame plin: Na globini od $200\text{ do }400\text{ metrov}$ ($650\text{ do }1300\text{ čevljev}$) ogromna teža zgornjega vodnega stolpca ($20\text{ do }40\text{ atmosfer}$ tlaka) ohranja milijarde litrov $CO_2$ raztopljenih v hladni spodnji vodi, natanko tako kot pokrovček na steklenici šampanjca pod pritiskom.
Sprožilec in rešitev za pobeg: Ko skalni/zemeljski plaz pljuskne v jezero, potres strese kotlino, sublakustrični vulkanski zračnik segreje dno ali hladna močna nevihta potisne površinsko vodo navzdol, se kos vode, nasičene z globokim $CO_2$, dvigne navzgor v plitvejše cone z nižjim tlakom. V trenutku iz raztopine zašibijo mikroskopski mehurčki $CO_2$ (nukleacija). Ker je voda, napolnjena s plinom, lažja (bolj plovna) od tekoče vode, se šumeči steber požene proti površju kot dvigalo in potegne celotno globoko plast jezera v nenadno verižno reakcijo, ki izstreli 50 do 100 metrov visok vodnjak v zrak in sprosti ogromno, ledeno mrzlo odejo $CO_2$, težjega od zraka.

"Mazuku" (Swahili for "Evil Wind") and Dry Volcanic $CO_2$ Traps Worldwide¶

You do not need a lake to be killed by volcanic $CO_2$. Around Mount Nyiragongo (DR Congo), Mammoth Mountain (California, USA), Campi Flegrei / Solfatara and Mount Etna (Italy), Laacher See (Germany), Mount Gambier (Australia), Hakoné / Mount Aso (Japan), and Rotorua (New Zealand), invisible cold $CO_2$ seeps straight out of soil fractures: - In East Africa, locals call these depressions Mazuku ("Evil Winds"): during the day, solar heat and wind disperse the gas, but at night, when the air cools and wind stops, pure $CO_2$ fills sunken footpaths, caves, trenches, and low huts up to chest height. - In snowy volcanic mountains like Mammoth Mountain in California or Mount Rainier / Mount Hood / Japanese Alps, $CO_2$ and $H_2S$ accumulate underneath the winter snowpack and fill tree wells, snow caves, ski patrol huts, and buried cabin basements, suffocating skiers who fall headfirst into a tree well or dig a snow shelter near a fumarole.

Globoki potop 2: Obalni "Laze" (klorovodikova kislina lava meglica) v primerjavi s celinskim "Vog" (vulkanski smog)¶

Travelers and coastal residents in volcanic islands (such as Hawaii's Kīlauea, Iceland's Reykjanes Peninsula, La Palma in the Canary Islands, Stromboli/Etna in Italy, and Vanuatu/Indonesia) frequently confuse Laze and Vog:

1. How Coastal "Laze" (Lava Haze) Forms and Why It Is Not Steam¶

When incandescent basaltic lava at $1,150^\circ\text{C}$ ($2,100^\circ\text{F}$) pours off a sea cliff into ocean seawater, it does not merely create harmless water steam. The extreme thermal shock triggers rapid chemical reactions (pyrohydrolysis) between molten silicate lava and dissolved magnesium chloride ($MgCl_2$) and sodium chloride ($NaCl$) sea salts, boiling off a dense, brilliant-white plume of concentrated hydrochloric acid ($HCl$) gas and acid rain droplets with a $\text{pH of }1.5\text{ to }2.0$ (as corrosive as battery acid or pure stomach acid). - At the exact same moment, steam explosions shatter the chilling crust of molten lava into millions of microscopic, needle-sharp volcanic glass shards (including fragile spun-glass threads called Pele's hair and hollow glass flakes called limu o Pele). - Why you must NEVER rub your eyes in a laze plume: If a sea breeze shifts and blows the white laze plume over sightseers or a tour boat, the hydrochloric acid stings the eyes immediately, prompting people to rub their eyes with their hands. Rubbing grinds microscopic volcanic glass needles straight into the cornea, causing severe corneal ulcerations. Instead, flush the eyes continuously with pouring clean water or saline for 15 minutes before touching the eyelids.

2. How Inland "Vog" (Volcanic Smog) Triggers Life-Threatening Asthma Crises¶

Vog forms when sulfur dioxide ($SO_2$) gas emitted from a volcanic vent reacts chemically in the atmosphere with oxygen, moisture, and sunlight over hours to days, converting into a hazy aerosol mist of sulfuric acid ($H_2SO_4$) droplets and microscopic ammonium sulfate particles ($PM_{2.5}$, smaller than $2.5\text{ micrometers}$). - Ker so delci kislinskega sulfata $PM_{2,5}$ mikroskopski majhni, obidejo naravni filtracijski sistem nosu in prodrejo naravnost v najgloblje alveole in bronhiole v pljučih. - Pri ljudeh z astmo, KOPB, kroničnim bronhitisom, srčnimi boleznimi, dojenčkih in nosečnicah že nizke koncentracije $SO_2$ ($0,5\text{ do }5\text{ ppm}$) in vog sprožijo takojšnjo, močno refleksno bronhokonstrikcijo (zapiranje dihalnih poti). - Protokol zavetja v zaprtih prostorih za Vog / $SO_2$: Če nad vašo sosesko piha močan oblak ali oblak $SO_2$ in se ne morete evakuirati zaradi bočnega vetra, pojdite v prostor, zaprite in zalepite vsa okna in vrata, nastavite klimatsko napravo na Recirkulacija / notranji zrak (zapiranje zunanje lopute za svež zrak), zaženite HEPA zrak čistilec, opremljen s kemičnim filtrom z aktivnim ogljem/kalijevim permanganatom ali sodo bikarbono, ali obesite vlažne rjuhe, poškropljene z raztopino sode bikarbone in vode ($2\text{ žlici}$ sode bikarbone na liter vode) pred ohišjem ventilatorja, da čistite kisle aerosole iz zraka v prostoru.

Zapozneli nekardiogeni pljučni edem (24- do 48-urna past 'utopitve na suhem')

Vsakdo, ki vdihne velik odmerek žveplovega dioksida ($SO_2$), klorovodikove kisline ($HCl$), vodikovega sulfida ($H_2S$) ali vodikovega fluorida ($HF$) in preživi začetni napad kašlja, mora biti pod nadzorom v bolnišnici 24 do 48 ur, tudi če se eno uro po tem počuti veliko bolje. ubežati perju. Jedki kisli plini in $H_2S$ poškodujejo mikroskopsko alveolarno-kapilarno membrano globoko v pljučih; 6 do 48 ur po izpostavitvi lahko tekočina, bogata z beljakovinami, nenadoma izteče iz krvnega obtoka in preplavi zračne mešičke v pljučih (zapozneli kemični pljučni edem/sindrom akutne respiratorne stiske [ARDS]), kar povzroči rožnat penast izpljunek, hudo kratko sapo in smrtno odpoved dihanja.

Fiziološki pragi koncentracije za koncentracijo za $CO_2$, $H_2S$ in $SO_2$¶

Razumevanje, kako hitro se simptomi stopnjujejo, ko koncentracije plinov naraščajo, pojasnjuje, zakaj je lahko čakanje celo 60 sekund v vulkanski depresiji usodno (podatki, zbrani iz NIOSH, OSHA in USGS Program vulkanskih nevarnosti):

Koncentracija plina v zraku (deli na milijon [ppm] ali prostorninski %)	Fiziološki učinek ogljikovega dioksida ($CO_2$).	Hydrogen Sulfide ($H_2S$) Physiological Effect	Žveplov dioksid ($SO_2$) Fiziološki učinek
$0,5\text{ do }5\text{ ppm}$	Normalni zunanji zrak je $\sim 420\text{ ppm}$ ($0,042\%$): popolnoma neškodljiv.	Močan smrad po "gnilih jajcih"; varno za kratko izpostavljenost.	Oster vonj po zažganih vžigalicah; sproži takojšnje piskajoče dihanje in bronhospazem pri ljudeh z astmo.
$10\text{ do }50\text{ ppm}$	Neškodljivo.	Zbadanje v očeh (konjunktivitis "plinskega očesa"), glavobol, slabost in draženje grla po 1 uri.	Hud kašelj, dušenje, krvavitve iz nosu in pekoče oči v 1 do 5 minutah.
$100\text{ do }150\text{ ppm}$	Neškodljivo.	KRITIČNI PRAG: Paralizira voh (vohalni živec) v 2 do 15 sekundah, tako da vonj po gnilih jajcih popolnoma izgine; povzroča resne poškodbe pljuč/oči (NIOSH IDLH = 100 ppm).	Takojšnje nevarno za življenje ali zdravje (NIOSH IDLH = 100 ppm): Jedka žveplova kislina opeče zgornje in spodnje dihalne poti v nekaj minutah.
$500\text{ do }1.000\text{ ppm}$ ($0,05\%\text{ do }0,1\%$)	Normalen zrak v razredu: neškodljiv.	TAKOJŠNJE »NOKDOWN« V 1 DO 2 VDIHIH: Paralizira dihalni center možganskega debla in blokira celično citokrom oksidazo; hitra koma in srčni zastoj.	Hitro smrtno v 1 do 10 minutah zaradi akutnega laringealnega spazma, puščanja dihalnih poti in kemične asfiksije.
$30.000\text{ do }50.000\text{ ppm}$ ($3\%\text{ do }5\%$)	Hitrost dihanja se podvoji; utripajoč glavobol, potenje, omotica in zmedenost v 5 do 15 minutah (NIOSH IDLH = 40.000 ppm [4 %]).	Takojšnja smrt.	Takojšnja smrt.
$100.000\text{ do }300.000\text{ ppm}$ ($10\%\text{ do }30\%$)	Nezavest pri 1 do 3 vdihih (manj kot 60 sekund), generalizirani krči in smrt zaradi hiperkapničnega/hipoksičnega zadušitve.	Takojšnja smrt.	Takojšnja smrt.

Zaščita pitne vode, živine in kože pred vodikovim fluoridom ($HF$) in kislim dežjem¶

Ko aktivni vulkan razplini ali izbruhne fin pepel, se vodikov fluorid ($HF$) in žveplov dioksid ($SO_2$) kondenzirata na padajočih delcih pepela in dežnih kapljicah: 1. Takoj odklopite strešne cisterne za deževnico: Če se vaše gospodinjstvo zanaša na strešne rezervoarje za zbiranje deževnice, odklopite žlebove odtočne cevi od rezervoarja za shranjevanje, preden pride plin ali oblak pepela. Kisli dež in pepel, prekrit s fluoridom, ki ga spereta s strehe, lahko vodo iz cisterne spremenita v strupeno (povzročita akutno zastrupitev s fluoridom, hudo bruhanje in hipokalcemične srčne aritmije). 2. Zaščitite živino in hišne ljubljenčke: živali na paši (zlasti ovce, govedo, konji in koze) zaužijejo strupene odmerke fluora, ko jedo travo, posuto z vulkanskim pepelom, prevlečenim z $HF$, ali pijejo iz plitvih luž, zaradi česar se v nekaj urah razvije smrtna akutna fluoroza. Živino spravite v pokrite hleve in jo nahranite s shranjenim čistim senom in pokrito vodo.

Pogosta vprašanja¶

Why can't I use an N95 mask, a gas mask, or a wet towel over my face to breathe inside a volcanic Carbon Dioxide (CO2) pocket or limnic eruption cloud?

Filter masks (including N95s, P100s, and military chemical cartridge gas masks) and wet cloths work only by filtering dust particles or absorbing reactive chemical gases out of air that still contains normal oxygen. Carbon dioxide (CO2) is an unreactive asphyxiant gas that is 1.52 times heavier than air: when it pools in a valley or depression, it physically pushes the breathable oxygen out of the space, dropping oxygen from 21 percent down to near zero while raising CO2 to 15 to 50 percent. No filter can manufacture oxygen out of pure CO2; only climbing immediately to higher ground or breathing from a self-contained compressed air tank (SCBA) will keep you alive.

Why do people think a Hydrogen Sulfide (H2S) gas leak has stopped right before they pass out?

Hydrogen sulfide (H2S) is famous for smelling strongly like rotten eggs at very low, relatively harmless concentrations (0.01 to 30 parts per million). However, once H2S reaches life-threatening concentrations above 100 to 150 ppm, the gas chemically paralyzes the human olfactory nerve inside the top of the nose within 2 to 15 seconds (olfactory fatigue/paralysis). Victims suddenly stop smelling the rotten egg odor, mistakenly believe the wind has blown the gas away, stay in the area, and collapse unconscious a moment later when concentrations hit 500 ppm.

Why does baking soda (sodium bicarbonate) mixed in water work better than plain water on a cloth during a Sulfur Dioxide (SO2) or Hydrochloric Acid (Laze) plume?

Both sulfur dioxide (SO2, which forms sulfurous acid on wet membranes) and coastal lava haze (laze, which is concentrated hydrochloric acid mist, HCl) are strong acidic gases. While a cloth dampened with plain water traps some acid mist, soaking the cloth in water mixed with household baking soda (sodium bicarbonate, an alkaline base, roughly 1 to 2 tablespoons per cup of water) creates an active chemical scrubber: as you inhale through the fabric, the alkaline sodium bicarbonate neutralizes the sulfuric and hydrochloric acid molecules into harmless salt, water, and tiny amounts of CO2 before they reach your throat and lungs.

Why is a stalled car engine or seeing dead birds on the ground an immediate sign to hold your breath and run uphill?

Because volcanic carbon dioxide (CO2) is completely invisible and odorless, you cannot see or smell a lethal "Mazuku" gas pocket sitting in a low dip in the road or a valley trail. However, small birds, rodents, and insects living right on the ground surface are immersed in the heaviest bottom layer of the CO2 first and die of asphyxiation within seconds; similarly, a gasoline or diesel car engine requires at least 13 to 15 percent atmospheric oxygen to sustain combustion, so when a car drives into a dense CO2 pocket in a road dip, the engine immediately chokes and stalls. If your car stalls in a volcanic valley or you see dead birds/animals, hold your breath, abandon the car, and run straight uphill.

Has anything been done to stop Lake Nyos and Lake Monoun in Cameroon from erupting again?

Yes. Following the 1986 Lake Nyos disaster that killed 1,746 people, international scientists installed permanent degassing polyethylene pipes reaching from floating rafts down to the bottom of both Lake Nyos (starting in 2001) and Lake Monoun (2003). These vertical pipes act as controlled artificial fountains that continuously siphon small, safe amounts of CO2-rich bottom water up to the surface so the gas vents harmlessly into the wind every day, successfully removing the vast majority of accumulated gas from both lakes; however, solar-powered CO2 sirens remain active, and other deep volcanic lakes worldwide still require vigilance.

What is "Pele's hair" in a coastal lava plume, and why must you never brush it off your skin or rub your eyes?

When molten lava fountains into the air or explodes on contact with ocean seawater, escaping gas bubbles stretch tiny droplets of liquid silicate rock into golden-brown strands of pure volcanic glass less than 0.5 millimeters thick, known as Pele's hair. Wind carries these brittle, needle-sharp glass fibers kilometers downwind inside laze and eruption plumes; if you rub your eyes or wipe your skin vigorously with your palm, the glass needles snap and embed deep into your cornea or skin like fiberglass splinters. Always rinse eyes and skin by pouring generous streams of clean water first without rubbing.

Viri preverjeni¶

Program geološkega raziskovanja Združenih držav (USGS) za nevarnosti vulkanov: Vulkanski plini in njihovi učinki ($CO_2$, $SO_2$, $H_2S$, $HF$ in obalna klorovodikova kislina), vključno z nasveti o nevarnosti Mammoth Mountain Tree-Well/Snow-Pit $CO_2$ in Kīlauea Protokoli Vog/Laze.
International Volcanic Health Hazard Network (IVHHN), Svetovna zdravstvena organizacija (WHO) in British Geological Survey (BGS): Smernice o pripravljenosti pred, med in po izpostavljenosti vulkanskemu plinu, kislemu dežju, Vogu in Laze.
Centri za nadzor in preprečevanje bolezni (CDC/NIOSH, Združene države) in Uprava za varnost in zdravje pri delu (OSHA, Združene države): Takojšnje nevarne za življenje ali zdravje (IDLH) koncentracije in žepni vodnik po kemičnih nevarnostih za ogljikov dioksid ($CO_2$), vodikov sulfid ($H_2S$), žveplov dioksid ($SO_2$), vodikov klorid ($HCl$) in vodikov fluorid ($HF$).
Urad Združenih narodov za usklajevanje humanitarnih zadev (OCHA) in Observatorij vulkana Goma (OVG): Mazuku (žep suhega ogljikovega dioksida) in zgodnje opozarjanje na izbruh jezera Kivu/jezero Nyos Limnic in standardi za evakuacijo na visokih tleh.

Gas / Plume Name & Formula	Specific Gravity (vs. Normal Air = \(1.00\))	Smell, Color, and Warning Signs	Lethal Concentration & Mechanism of Death	What Protective Gear Works?
1. Carbon Dioxide (\(CO_2\)) (Limnic Eruptions, "Mazuku" Death Pockets, Cold Trap Seeps)	\(1.52\text{x}\) heavier than air (Hugs ground, fills valleys, trenches, basements, and tree wells)	Colorless and 100% ODORLESS. High concentrations (\(>5\%\)) taste slightly sour/carbonated on the tongue and sting the nostrils like soda fizz.	\(7\%\text{ to }10\%\) (\(70,000\text{ to }100,000\text{ ppm}\)): Dizziness, pounding headache, gasping breath (hypercapnic drive), unconsciousness in minutes. \(15\%\text{ to }30\%\): Instant knockdown in 1 to 3 breaths, convulsions, coma, and asphyxiation death within minutes.	ONLY Self-Contained Breathing Apparatus (SCBA) air tank or climbing uphill to fresh air. (Gas masks, N95s, and wet cloths are 100% useless* against \(CO_2\)).*
2. Hydrogen Sulfide (\(H_2S\)) (Geothermal Hot Springs, Mud Pots, Solfataras)	\(1,19\text{x}\) težji od zraka (Bazeni v termalnih bazenih, kopališčih in požiralnikih)	Brezbarven. Močan vonj po "gnilih jajcih" pri nizkih ravneh (\(0,01\text{ do }30\text{ ppm}\)), ki mu sledi nenadna popolna izguba vonja nad \(100\text{ do }150\text{ ppm}\) (vohalna paraliza).	\(50\text{ do }100\text{ ppm}\): Hudo draženje oči (keratokonjunktivitis "plinskega očesa") in kašelj. \(500\text{ do }1.000+\text{ ppm}\): Takojšnji "knockdown" v 1 vdihu: blokira citokrom c oksidazo v celičnih mitohondrijih (identično zastrupitvi s cianidom) in paralizira dihalni center možganskega debla.	SCBA rezervoar za zrak za visoke/neznane ravni; beg navkreber v veter.
3. Žveplov dioksid (\(SO_2\)) in Vog (aktivni vulkanski žarki, kraterji, razpoke)	\(2,26\text{x}\) težji od zraka, ko je hladen (Dvigne se v vročih termalnih oblakih, nato pa se spusti v doline z vetrom)	Brezbarven plin (ali meglen modro-siv Vog sulfatni aerosol). Oster, oster, zadušljiv vonj po "zažgani vžigalici" ali zažganem ognjemetu pri samo \(1\text{ do }3\text{ ppm}\).	\(5\text{ do }20\text{ ppm}\): Takojšen močan kašelj, pekoč občutek v grlu in hud usoden bronhospazem pri ljudeh z astmo/KOPB. \(100+\text{ ppm}\): Reagira s pljučno vlago in tvori žveplovo in žveplovo kislino, kar povzroča kemične opekline dihalnih poti in zapozneli pljučni edem.	NIOSH/EN respirator s kartušo za kisle pline + filter za delce P100; rezerva v sili: mokra krpa, namočena v vodo + soda bikarbona.
4. Klorovodikova kislina "Laze" (\(HCl\) + steklo) (vstopni oblaki lave v obalnem oceanu)	Gosta bela meglica, podobna pari, ki jo vodoravno piha morski vetrič vzdolž obale	Svetlo bel valovit oblak, ki je videti kot neškodljiva para, z ostrim ostrim vonjem po belilu/kislini in drobnim zrnatim prahom.	Koncentrirane kapljice klorovodikove kisline (\(HCl\)) (\(\text{pH } 1,5\text{ do }2,0\), tako jedke kot želodčna kislina ali baterijska kislina), pomešane z mikroskopskimi *iglami iz vulkanskega stekla (delci Pelejevih las)*. Povzroča akutne kemične opekline pljuč, laringealni spazem in odrgnine roženice.	Kislin plin + respirator P100 + zaprta očala proti brizganju kemikalij; nikoli ne stojite ob vetru od vstopa v oceansko lavo.
5. Vodikov fluorid (\(HF\)) (eksplozivni prameni pepela in razplinjena magma)	0,70 $ kot monomer, vendar tvori kapljice težke kisle megle in prekrije padajoči vulkanski pepel	Brezbarven dimni plin/megla z dražečim kislim vonjem; prekriva travo na pašnikih in onesnažuje cisterne za deževnico.	Prodira v kožo in pljuča, da veže kalcij in magnezij v krvi, kar povzroči hudo hipokalciemijo, hipomagneziemijo, fluorozo in smrtonosno ventrikularno fibrilacijo, srčni zastoj (ubije pašne ovce/govedo in onesnaži pitno vodo).	Respirator s kislim plinom; odklopite strešne žlebove za zbiranje deževnice, preden preidejo oblaki pepela/plina; zdravite kožne opekline s kalcijevim glukonatnim gelom.

Vulkanski plinski oblaki, leni oblaki in limnični izbruhi¶

Naredi to zdaj¶

Volcanic gas, laze, and limnic eruption survival decision tree¶

Comparing the 5 lethal volcanic and crater-lake gas hazards¶

Deep dive 1: Limnic eruptions (Crater lake overturns) and "Mazuku" death pockets¶

How a limnic eruption works (The "Champagne Bottle" Lake Mechanism)¶

"Mazuku" (Swahili for "Evil Wind") and Dry Volcanic \(CO_2\) Traps Worldwide¶

Globoki potop 2: Obalni "Laze" (klorovodikova kislina lava meglica) v primerjavi s celinskim "Vog" (vulkanski smog)¶

1. How Coastal "Laze" (Lava Haze) Forms and Why It Is Not Steam¶

2. How Inland "Vog" (Volcanic Smog) Triggers Life-Threatening Asthma Crises¶

Fiziološki pragi koncentracije za koncentracijo za \(CO_2\), \(H_2S\) in \(SO_2\)¶

Zaščita pitne vode, živine in kože pred vodikovim fluoridom (\(HF\)) in kislim dežjem¶

Pogosta vprašanja¶

Viri preverjeni¶

Sorodni vodniki¶

Koncentracija plina v zraku (deli na milijon [ppm] ali prostorninski %)	Fiziološki učinek ogljikovega dioksida (\(CO_2\)).	Hydrogen Sulfide (\(H_2S\)) Physiological Effect	Žveplov dioksid (\(SO_2\)) Fiziološki učinek
\(0,5\text{ do }5\text{ ppm}\)	Normalni zunanji zrak je \(\sim 420\text{ ppm}\) (\(0,042\%\)): popolnoma neškodljiv.	Močan smrad po "gnilih jajcih"; varno za kratko izpostavljenost.	Oster vonj po zažganih vžigalicah; sproži takojšnje piskajoče dihanje in bronhospazem pri ljudeh z astmo.
\(10\text{ do }50\text{ ppm}\)	Neškodljivo.	Zbadanje v očeh (konjunktivitis "plinskega očesa"), glavobol, slabost in draženje grla po 1 uri.	Hud kašelj, dušenje, krvavitve iz nosu in pekoče oči v 1 do 5 minutah.
\(100\text{ do }150\text{ ppm}\)	Neškodljivo.	KRITIČNI PRAG: Paralizira voh (vohalni živec) v 2 do 15 sekundah, tako da vonj po gnilih jajcih popolnoma izgine; povzroča resne poškodbe pljuč/oči (NIOSH IDLH = 100 ppm).	Takojšnje nevarno za življenje ali zdravje (NIOSH IDLH = 100 ppm): Jedka žveplova kislina opeče zgornje in spodnje dihalne poti v nekaj minutah.
\(500\text{ do }1.000\text{ ppm}\) (\(0,05\%\text{ do }0,1\%\))	Normalen zrak v razredu: neškodljiv.	TAKOJŠNJE »NOKDOWN« V 1 DO 2 VDIHIH: Paralizira dihalni center možganskega debla in blokira celično citokrom oksidazo; hitra koma in srčni zastoj.	Hitro smrtno v 1 do 10 minutah zaradi akutnega laringealnega spazma, puščanja dihalnih poti in kemične asfiksije.
\(30.000\text{ do }50.000\text{ ppm}\) (\(3\%\text{ do }5\%\))	Hitrost dihanja se podvoji; utripajoč glavobol, potenje, omotica in zmedenost v 5 do 15 minutah (NIOSH IDLH = 40.000 ppm [4 %]).	Takojšnja smrt.	Takojšnja smrt.
\(100.000\text{ do }300.000\text{ ppm}\) (\(10\%\text{ do }30\%\))	Nezavest pri 1 do 3 vdihih (manj kot 60 sekund), generalizirani krči in smrt zaradi hiperkapničnega/hipoksičnega zadušitve.	Takojšnja smrt.	Takojšnja smrt.