Yon vòlkan se yon montay ki louvri anba nan yon rezèvwa wòch k ap fonn anba sifas tè a. Kontrèman avèk pifò montay yo, ki pouse depi nan baz la, vòlkan yo se chemine kote wòch k ap fonn ap monte nan sifas tè a. Lè presyon nan gaz ki nan wòch k ap fon yo vin twò gwo, yon eripsyon fèt. Eripsyon yo kapab kalm oswa eksplozif. Yo ka se ekoulman lav, peyizaj ki plat, gaz pwazon, ak wòch k ap vole ak sann ki kapab pafwa vwayaje sou yon distans plizyè santèn mil nan direksyon van an.
Akòz gwo chalè yo, ekoulman lav la se danje pou gwo dife. Ekoulman lav la detwi tout bagay ki nan trajektwa yo, men pifò deplase dousman ase pou moun kapab deplase ale.
Sann fre vòlkan an, ki fèt avèk wòch ki kraze, kapab abrazif, asid, plen sab, plen gaz, ak epi yo gen odè. Menmsi gaz asid la ak sann nan pa imedyatman danjere pou pifò adilt yo, yo kapab lakòz domaj nan poumon sou tibebe piti yo, sou granmoun aje yo, ak sou moun ki soufri maladi respiratwa grav. Sann vòlkan kapab domaje machinri, tankou motè ak ekipman elektrik. Pil sann ki melanje avèk dlo vin lou, epi li kapab lage do kay atè. Sann vòlkan kapab afekte moun sou yon distans anpil santèn mil apati kòn vòlkan.
Eksplozyon vòlkan yo ki pran direksyon antravè, ki rele "eksplozyon lateral" kapab lanse gwo mòso wòch avèk trè gwo vitès pou yon distans plizyè mil. Eksplozyon sa yo kapab touye moun avèk enpak yo, lè y ap antre nan tè, oswa avèk chalè yo. Yo rekonèt yo poutèt yo detwi forè yo nèt.
Yo jwenn vòlkan ki aktif Ozetazini yo sitou nan Hawaii, Alaska ak Nòdwès Pasifik la. Zòn danje toutotou yon vòlkan kouvri apeprè yon reyon 20 mil, men ka gen danje sou yon distans 100 mil oswa plis nan yon vòlkan.
Before a Volcanic Eruption
The following are things you can do to protect yourself, your family and your property in the event of a volcanic eruption.
- Build an Emergency Supply Kit, which includes items like non-perishable food, water, a battery-powered or hand-crank radio, extra flashlights and batteries. You may want to prepare a portable kit and keep it in your car in case you are told to evacuate. This kit should also include a pair of goggles and disposable breathing masks for each member of the family.
- Make a Family Emergency Plan. Your family may not be together when disaster strikes, so it is important to know how you will contact one another, how you will get back together and what you will do in case of an emergency.
During a Volcanic Eruption
- Follow the evacuation order issued by authorities and evacuate immediately from the volcano area to avoid flying debris, hot gases, lateral blast and lava flow.
- Be aware of mudflows. The danger from a mudflow increases near stream channels and with prolonged heavy rains. Mudflows can move faster than you can walk or run. Look upstream before crossing a bridge and do not cross the bridge if a mudflow is approaching.
- Avoid river valleys and low-lying areas.
- Remember to help your neighbors who may require special assistance - infants, elderly people and people with access and functional needs.
Protection From Falling Ash
- If you are unable to evacuate, and in order to protect yourself from falling ash, you should remain indoors with doors, windows and ventilation closed until the ash settles.
- If you have a respiratory ailment, avoid contact with any amount of ash. Stay indoors until local health officials advise it is safe to go outside.
- Listen to a battery-powered radio or television for the latest emergency information.
- Wear long-sleeved shirts and long pants.
- Use goggles and wear eyeglasses instead of contact lenses.
- Use a dust mask or hold a damp cloth over your face to help with breathing.
- Stay away from areas downwind from the volcano to avoid volcanic ash.
- Stay indoors until the ash has settled unless there is a danger of the roof collapsing.
- Close doors, windows, and all ventilation in the house (chimney vents, furnaces, air conditioners, fans and other vents.
- Clear heavy ash from flat or low-pitched roofs and rain gutters.
- Avoid running car or truck engines. Driving can stir up volcanic ash that can clog engines, damage moving parts, and stall vehicles.
- Avoid driving in heavy ash fall unless absolutely required. If you have to drive, keep speed down to 35 MPH or slower.
After a Volcanic Eruption
- Go to a designated public shelter if you have been told to evacuate or you feel it is unsafe to remain in your home. Text SHELTER + your ZIP code to 43362 (4FEMA) to find the nearest shelter in your area (example: shelter 12345).
- Local authorities may not immediately be able to provide information on what is happening and what you should do. However, you should listen to NOAA Weather Radio, watch TV, listen to the radio or check the Internet often for official news and instructions as they become available.
U.S. Geological Survey
- Volcano Hazards Program. Website with volcano activity updates, feature stories, information about volcano hazards and resources. Available online at: http://volcanoes.usgs.gov
Find additional information on how to plan and prepare for a volcanic eruption and learn about available resources by visiting the following websites:
- Federal Emergency Management Agency
- NOAA Watch
- American Red Cross
- U.S. Geological Survey Volcano Hazards Program
Listen to Local Officials
Learn about the emergency plans that have been established in your area by your state and local government. In any emergency, always listen to the instructions given by local emergency management officials.