Hidden Dangers in a Benign UK Landscape
Golden grasses waving over a virtually flat field touched by a rainbow. The open meadow, pictured above, could hardly seem more inviting to walkers on a brisk autumn day. But looks can be deceptive and that sweet looking field can be a dangerous man eater.
The meadow is actually a peat bog - more specifically a blanket bog - and while it's a rich habitat for wildlife watchers, it hides potential dangers for the unwary.
The UK has 15% of the blanket peatland bogs in the world. But upland peat bogs of the kind that are found in Britain are uncommon in most of the continental United States. So visitors who arrive to go hill walking in Dartmoor, Exmoor, the Yorkshire Moors, the Lake District, Scotland, and Wales may not recognize them or know how to cross them safely. If you expect that bogs are like wet, muddy swamps and thus easy to avoid you'd be wrong. Peatlands may contain fewer solids per cubic yard than milk, but most of the time, you'd never know by looking.
All peat bogs are wet and waterlogged, but what catches the inexperienced unawares is that the water may not be readily apparent. Walkers who anticipate waterlogged soil and mud in low lying areas can be caught out by British bogs on mountains and high moors.
How a bog is formed
Essentially bogs are formed when poorly drained, depressed areas fill with plant matter, usually sphagnum moss but also other mosses and grasses. The growing mosses compress the layers below, forming peat, but also trap and hold rainwater which cannot drain away and is not taken up by the plants. In the UK, there are two common kinds of peat bogs:
- Blanket bog - As the name suggests, this kind of bog, formed of spiky grasses and moss, forms an undulating blanket that smothers a landscape under a high acid layer of peat that is fed by rainwater and snowmelt rather than ground water. There are vast stretchs of blanket bog in the UK, the majority of it in Scotland. The depth of the peat can range from two or three meters (about six to ten feet) up to about five meters (around 16 feet). Rainwater tends to flow through the dryer looking top layer of the blanket bog, which floats like a carpet on top of the waterlogged moss beneath. In some areas, especially where the blanket bog extends to the sea, underground streams can be hidden below the surface, eroding the "solid" carpet of growing moss from below.
- Raised bog - This forms in a lake bed or flat, marshy area that gradually fills up with mosses and plants, each layer compressing the next. Eventually, the bog becomes too thick for water to penetrate to its center and peat is formed. The surface continues to grow, fed by rainwater and snowmelt, evenually forming a dome shape. In wet weather, the underlying peat can become spongy and unstable.
How to stay safe on a bog
Because they are highly acid, bog lands don't have a great variety of plantlife. But, they do attract many small mammals and birds - so they're appealling for wildlife watchers. With a few precautions, most people can enjoy a day out near or even on a bog:
- Avoid winter and wet weather - Rain can make the usually drier top laters soak up water like a sponge. Snow or ice can conceal dangerously deep puddles. UK bogs are much safer in dry, summer weather.
- Don't go by yourself - It's always a good idea to walk with a buddy, just to be safe.
- Don't underestimate puddles - What looks like a small puddle or a narrow stream you can wade across could be very deep. Every year, mountain and moor rescue teams pull experienced hikers who have sunk waist deep in what looked like a slightly mucky path.
- Keep your cell phone fully charged - But keep in mind that many wild areas have poor phone reception. A walking buddy is safer than a mobile phone.
- Tell someone where you are going - And when you expect to arrive or return.
- Keep to established trails - Stop into a local bookshop, tourist office or national park center for maps and advice about trails and planned walks. Most areas popular with visitors will have recommended trails. If there are no clearly marked trails, go with a guide. Local tourists offices or hotels can provide information about knowledgeable local guides who often offer group walks and excursions on the moors.
- Keep your pet on a leash - More than one sensible walker has come to grief chasing their dog into a bog.
- Back out - If you find the area in which you are walking becoming waterlogged, or if the path you are on seems to end in waterlogged ground, stop and back out the way you came. Trying to find a way forward can get you deeper and deeper onto dangerous ground.
- Mind your navigation - If you are crossing a large and relatively featureless bog, it is very easy to lose your bearings. So it's important to know where you are when you start out and exactly where you are heading. When crossing the bog, you will probably backtrack around wet areas and take a lot of detours. Taking frequent compass readings will keep you going in the right direction.
- Learn how to get out of a bog - If you are unlucky and sink into a bog, you need to know how to get yourself out or how to avoid sinking further while you wait for help. This website offers some good advice about getting out of a bog, but the best advice is to know how to identify dangerous ground and avoid it altogether.