Mga Bulkan

Larawan ng lava na namumula sa init na sumasambulat mula sa isang bulkan

Himukin ang iba na kumilos sa pamamagitan ng pagiging isang halimbawa, Mangakong Maghahanda at sabihan ang iba tungkol dito!

Mangakong Maghahanda

Ang bulkan ay isang bundok na may bukana na paibaba sa isang imbakan ng tunaw na bato sa iallim ng balat ng lupa. Hindi tulad ng ibang bundok, na itinutulak paitaas mula sa ibaba ang mga bulkan ay mga singawan kung saan tumatakas ang mga tunaw na bato paakyat sa balat ng lupa. Kapag naging napakalakas ng presyon mula sa mga gas sa loob ng mga tunaw na bato, may pagsabog na nagaganap. Ang mga pagsabog ay maaaring maging tahimik o sumasambulat. Maaaring magkaroon ng pagdaloy ng lava, napipitpit na anyong lupa, nakalalason na gas, at lumilipad na bato at abo na kung minsan ay imaabot ng daan-daang milya pababa ng ihip ng hangin.

Dahil sa tindi ng init nito, ang pagdaloy ng lava ay napakalaking panganib ng sunog. Sinisira ng dumadaloy na lava ang lahat ng haharang dito, ngunit karamihan ay mabagal ang pagdaloy kaya nakakalayo ang mga tao.

Ang sariwang abo nagawa sa nadurog na bato, ay maaaring magaspang, acidic, mabuhangin, may gas at may amoy. Bagaman hindi mapanganib sa karamihang matatanda, ang acidic na gas at abo ay maaaring makapagdulot ng pinsala sa baga ng maliliit na sanggol, hanggang sa mas nakatatanda at sa mga nagdurusa mula sa malulubhang karamdaman sa paghinga. Ang abong mula sa bulkan ay maaari rin makasira ng makinarya, kasama na ang mga makina at kagamitang de-kuryente. Ang natipong abo na humalo sa tubig ay nagiging mabigat at maaaring makasira ng mga bubong. Ang abo mula sa bulkan ay maaaring makaapekto sa mga taong daan-daang milya ang layo mula sa bibig ng bulkan.

Ang mga pagsabog ng bulkan na pagilid, na tinatawag na mga "lateral blast," ay nakapagbubuga ng malalaking tipak ng bato nang napakabilis na aabot nang ilang milya ang layo. Ang mga pagsabog na ito ay nakamamatay sa pamamagitan ng pagtama, paglubog o init. Kilala ang mga ito na nakapagpapatumba ng mga buong kagubatan.

Ang mga pagsabog ng bulkan ay maaaring sabayan ng iba pang likas na panganib, kasama na ang mga lindol, pagdaloy ng putik at mga flash flood, pagkahulog ng bato at mga pagguho ng lupa, acid rain, sunog, at (kung akma sa mga kondisyon) mga tsunami.

Ang mga aktibong bulkan s U.S. ay matatagpuan sa Hawaii, Alaska at sa Pacific Northwest. Ang mapanganib na lugar sa paligid ng isang bulkan ay sumasaklaw ng 20-milya palibot, subalit maaaring may ilang panganib na aabot ng 100 milya o higit pa mula sa isang bulkan.

A smoldering volcanic crater.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.

Publications

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

Related Websites

Find additional information on how to plan and prepare for a volcanic eruption and learn about available resources by visiting the following websites:

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.

Last updated: 04/02/2013 - 03:02 PM