Volcanic Eruptions

What? I can hear … I thought this blog was about UK preparedness? Well, it is: this is a Cabinet Office report on what civil emergencies we could face here in the UK, and some items on the list might make you do a double-take. The highest priority is a pandemic, followed by coastal flooding and catastrophic terrorist attacks. And the fourth on the list is “Severe effusive (gas-rich) volcanic eruptions abroad”, which might be a bit of a surprise. It certainly was to me. Its on page 12 of the pdf that’s linked to above.

We had the ash eruption from Iceland way in 2010, and that was inconvenient for fliers. But scientific experts are saying that gas eruptions are somewhat more likely now, and more dangerous in themselves as well, from the sound of it. And possible preparations for the two types of explosions don’t entirely overlap.

Because of where we sit on the globe geographically, Iceland contains most of the volcanoes which are the main issue for us in relation to ash – but a big enough one even in the Far East still may have the ability to affect us later in the year, and in the year after, because of gases. The report quotes mortality in England during 1783-84, when Grimsvotn Volcano exploded in Iceland: mortality that summer was up 10-20% in England, as well as the rest of Western Europe. Thats really high, and worth a few precautions.


No one in the UK lives within a blast or lava flow area, so at least we’ve got that on our side! So prepping is mostly about ash, with awareness of gas. I won’t cover the standard prepper-type things, like food, water, emergency radio, though there are a few specific reasons related to vulcanism to stock them.

To state it plainly: these aren’t needed except in extreme eruptions, when I should think there will be broadcasts by the mainstream media. But I like to have as much advance knowledge about this sort of thing as possible: thats why I’m a prepper, after all. The only thing I’ve bought in extra, however, is four packs of clingfilm: clingfilm is the item of choice to keep our electrics and electronics safe from ash. Its a simple prep, easy to store, doesn’t decay, doesn’t cost much, why not get it in just for peace of mind? Then, if something does happen, the stuff in the shops will be available to people who don’t already know about prepping …

So, ash might fall on the UK from volcanoes which are comparatively nearby – Iceland, Italy – and it will probably do little more than interrupt aviation once again, as in 2010. That can’t be absolutely guaranteed, of course – maybe several volcanoes might go off at once, for instance? Just in case, therefore, the last half of this blog post is a summary of the precautions advised by the IVHHN, the International Volcanic Health Hazard Network. And I’m making sure my clingfilm is available to me!

But what about gas, which is what the Civil Emergencies Register refers to? There are two effects of the gas in volcanic eruptions: one is strictly localised, and has happened several times in Iceland recently, when villages downwind of an erupting volcano are evacuated, because of the toxic gases present in sufficient quantities to be dangerous to survival. That’s important for the Icelanders, but not going to affect us here in the UK.

The other effect of gas is continent-wide, and sometimes global: this is when toxic gases such as sulphur dioxide, chlorine and fluorine are released in such quantities that crop yields are very badly affected – not a nuclear winter caused by dust in the atmosphere, but a volcanic winter/volcanic acid rain caused by toxic gases (and maybe by dust as well, who knows?).

This is explored by the US Geological Survey.  The pithy little summary I’m quoting in this article is about one-third of the way down the page:

“The volcanic gases that pose the greatest potential hazard to people, animals, agriculture, and property are sulfur dioxide, carbon dioxide and hydrogen fluride. Locally, sulfur dioxide gas can lead to acid rain and air pollution downwind from a volcano. Globally, large explosive eruptions that inject a tremendous volume of sulfur aerosols into the stratosphere can lead to lower surface temperatures and promote depletion of the Earth’s ozone layer.”

I don’t see what we as individuals – or even our governments – can do about this global risk, apart from stocking up food, and the means to purify water and so on. It’s the scale of the potential event that makes me think that. The 1783-84 event described above probably wouldn’t cause the same level of deaths today, but it would cause some deaths. Bigger events still wouldn’t be planet-killers, and they wouldn’t kill off every human, but they would cause disruption and fatalities on a planetary scale. It’s much safer for you and your loved ones if you have some stocks in to see you through the first months of the troubles that would follow this sort of disaster.

Below, in any case, is the list of precautions for the much less serious issue of ash fall.

Stocking Up

Dust masks and eye protection.

Cling film, to keep ash out of electronics.

Chlorine tablets for use with tap water.

Classic preps: light, fuel, warmth, medication, first aid, cleaning supplies, money, a week’s drinking water and non-perishable food.

Communications: if you cover your equipment with clingfilm, of course, you won’t be able to use it … so you need at least one backup to get information. That might be a cheap radio that you regard as disposable, and you might experiment with sealing it inside a bag made of heavy plastic, see if that safeguards it. You still need two, though: one to store away long term, one for use during the emergency.

Preparing for ashfall

Close all doors and windows. Place damp towels at drafty places, tape drafty windows.

If you collect rainwater, disconnect the collection devices, cover any tanks.

Wrap all electronics in clingfilm, don’t uncover till totally ash free. Televisions, computers, cameras – volcanic ash is crystalline in structure, will scratch and abrade when removed by wiping or brushing.

Ensure livestock have clean food and water, and are protected.

Some bodies advise disconnecting drainpipes from gutters, so that the drains aren’t clogged … thats a big undertaking. I don’t think I’d do it if it wasn’t advised at the time, quite frankly, messing with the integrity of your guttering un-necessarily sounds like asking for trouble.

When ashfall starts

Don’t panic – get indoors as soon as you can, and stay indoors.

If you get warning, and you’re away from home, go home.

If outdoors, cover nose and mouth with fabric, get inside.

If you’re away from home but indoors when it starts, stay where you are till it stops.

Don’t make non-emergency calls, the phones will be overrun.

Don’t wear contact lenses.

Keep all windows and doors closed whenever possible. Keep everyone, and all animals, inside. Be safe.



If you’ve protected your electrics and electronics with clingfilm, make sure you can access a radio or other device enough to hear broadcast safety news.

Ash will have to be cleared from patios, paths, etc, but it seems that the main advice for a minimal ash fall will be to let it compost itself into the soil: volcanoes create very fertile soil after a while. But the mineral composition of each ash fall is distinctive, so follow the advice given out at the time.

Try to keep the ash out of your house: take off outside shoes at the door, and put them in plastic bags.

Water Supplies

If there’s ash in your water, let it settle and then filter the water that seems clear, through anything you have to hand – a pair of tights, anything.

Water contaminated by ash will usually become unpalatable before it becomes a health risk – the risk of toxicity is low, but chlorination is apparently inhibited in surface-collected water. And that means that microbes that usually get killed off by the water treatment in this country aren’t killed off. If in doubt, use chlorine tablets after filtering.

If there’s a lot of ash in the water supply, don’t use your dishwasher or washing machine, they’ll be damaged.

There may be water shortages, because of water demand for cleanup.


Animals can be endangered by eating grass and plants covered in ash containing hydrofluoric acid. Make sure your animals don’t have access to plants they normally eat until its safe.

If you have pets that you let go outside, brush them thoroughly before you allow them back in the house.


And here are some of the websites I’ve used in compiling this.

The International Volcanic Health Hazard Network

This is a prime source. It has several pamphlets and posters about preparation and hazards available.

The International Airways Volcano Watch

The London branch is run by the Met Office. Its a United Nations organisation, under the umbrella of the International Civil Aviation Authority, from what I can tell, and as far as I’m concerned, any organisation with that pedigree is drowning in red tape; even though the information is accurate, it may be slow to be updated.

The British Geological Survey, earth hazards section.

The Global Volcanism Program at the Smithsonian

The Icelandic Met Office

In English! And its an amazing site. Dig deep enough, and you’ll find some active webcams from the Meteorological Service.

5 thoughts on “Volcanic Eruptions

  1. keep up the good work Jan. This looking to be one of the most useful British Prepper Blogs. Now tackle Thermo nuclear war, go on, I dare you.


  2. Thats a very kind thing to say, thank you. Yikes to Thermonuclear War though … I’m very tempted to write about nuclear problems, actually, between dirty bombs, depleted uranium bullets, pre-existing background levels and incomplete disclosure of accidents, I think there are some issues there. Not for this weekend, but its on the list!

  3. Great blog! This volcano thing surprised me when I heard of the govt. exercise. Your blog has opened my eyes on the subject.
    Given that we have regular earth tremors here in Leicestershire (not altogether unrelated) this is timely.
    Keep up the good work!

    1. Thank you jansman, I appreciate that. It’s surprising how relevant it is, isn’t it! I’ve only ever experienced an earth tremor while on holiday in Italy (and since I was in Venice, I was a little bit worried about even a small tsunami effect) but never in the UK. Here’s hoping I never do :

      I’d be interested to know the next time you experience one.

      1. We have had two in the last few weeks, the epicentre being in Oakham, which is not far from me. I believe it clocked about 3 on the Richter Scale. Not bad for the UK.
        I can remember one Sunday afternoon some years ago, there was a good tremor and I was in the bath. I thought the gas boiler was blowing up! My Pakistani neighbours ran out into the middle of the road. Coming from their country they knew what it was, and were avoiding the house coming down on them (they told me this was taught from childhood). Interesting.

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