From all of the updates on Mount Agung, one thing people keep warning us about is the danger of Volcano ashes and how to protect yourself from it. Here are some of the things we learn about them…
WHAT ARE THEY?
Volcanic ash consists of tiny jagged pieces of rock and glass. Ash is hard, abrasive, mildly corrosive, conducts electricity when wet, and does not dissolve in water. Ash is spread over broad areas by the wind.
Volcanic ash is formed during explosive volcanic eruptions. Explosive eruptions occur when gases dissolved in molten rock (magma) expand as the magma rises, and then escape violently into the air, or when water is heated by magma and abruptly flashes into steam. The force of the escaping, expanding gas violently shatters solid rocks and shreds the magma blasting it into the air. Once airborne, the magma solidifies into fragments of volcanic rock and glass. Wind can then blow the tiny ash particles tens to thousands of kilometres away from the volcano.
IS IT DANGEROUS?
Falling ash can turn daylight into complete darkness. Accompanied by rain and lightning, the gritty ash can lead to power outages, prevent communications, and disorientate people.
Ashfalls vary widely in intensity, size of the ash particles, and the degree to which light from the sun is obscured or blocked completely. Because of the unexpected darkness during daylight hours, loud thunder and lightning, and the sometimes strong smell of sulphur during an ashfall, many people describe the experience as eerie and frightening, disorienting and confusing, or dreadful. In extreme ashfall, for example, when ash thickness is more than 5-10 cm (2-4 in), people may feel stunned and fearful of the conditions and may have difficulty breathing if a well-sealed shelter is not available. These thicknesses usually only occur within tens of kilometres of the vent. If caught outside during low visibility, people may become lost or extremely disoriented. If heavy ashfall continues for 12-60 hours or more (a very rare occurrence), roofs may collapse under the weight of the ash, resulting in more confusion, injuries, and even death.
Exposure to volcanic ashfall rarely endangers human life directly, except where very thick falls cause structural damage to buildings (e.g. roof collapse) or indirect casualties such as those sustained during ash clean-up operations or in traffic accidents. Short-term effects commonly include irritation of the eyes and upper airways and exacerbation of pre-existing respiratory disease such as asthma; serious health problems are rare. In addition, affected communities may experience increased levels of psychological distress. This is particularly the case when eruptions cause social and economic disruption.
People should avoid unnecessary exposure to ash and wear an effective face mask when outside to reduce inhalation of ash particles. People with existing respiratory problems should take special care to avoid exposure to airborne ash and should carry their medication with them.
WHAT TO PREPARE?
1. Stocking up on Essentials
A sustained ashfall may keep people housebound for hours or possibly days. Keep these items in your home to be prepared for ashfall:
– Specifically recommended dust masks and eye protection.
– Water to last 72 hours (one gallon per person per day).
– Non-perishable food for at least 72 hours for all family members, including pets.
– Plastic wrap (to keep ash out of electronics).
– Battery-operated radio and extra batteries.
– Lanterns or torches (flashlights) and extra batteries.
– Extra stocks of medication for both family and pets.
– First aid kit.
– Cleaning supplies (broom, vacuum cleaner & bags/filters, shovels etc).
– Small amount of money (ATM machines may not be working).
– Consider that you could be stuck in your vehicle, so store emergency supplies in your vehicle too.
2. Preparedness Actions to Take Before Ashfall
– Close doors and windows.
– Place damp towels at door thresholds and other draft sources. Tape draughty windows.
– Protect sensitive electronics and do not uncover until the environment is totally ash-free.
– Disconnect drainpipes/downspouts from gutters to stop drains clogging but allowing ash and water to empty from gutters onto the ground.
– If you use a rainwater collection system for your water supply, disconnect the tank prior to ash falling.
– If you have chronic bronchitis, emphysema or asthma, stay inside and avoid unnecessary exposure to the ash.
– Ensure livestock have clean food and water.
– If you have children, know your care provider’s/school’s emergency plan and have indoor games and activities ready.
Keep ash out of buildings, machinery, vehicles, downspouts, water supplies, and wastewater systems (for example, storm drains) as much as possible. The most effective method to prevent ash-induced damage to machinery is to shut down, close off or seal equipment until ash is removed from the immediate environment, but this may not be practical in all cases, especially for critical facilities. Minimize exposure to airborne ash by using dust or filter masks (or a wet cloth, for example, a handkerchief) and minimizing travel.
Coordinate cleanup activities with neighbours and community-wide operations (learn the cleanup guidelines and instructions of your local community and leaders). After an ashfall, promptly notify building owners to remove ash from roofs in a timely manner to prevent streets from being repetitively cleaned.
All infos are taken from https://volcanoes.usgs.gov/volcanic_ash/
Pics courtesy of: @Eyes_of_a_nomad