Peat facts for kids

Peat in Lewis, Scotland

A peat stack in Ness in the Isle of Lewis (Scotland).

Peat, or turf, is an accumulation of partially decayed vegetation. Peat forms in wetland bogs, moors, mires, and swamps.

Formation

Peat forms when plant material, usually in marshy areas, is inhibited from decaying fully by acidic and anaerobic conditions. It is composed mainly of marshland vegetation: trees, grasses, fungi, as well as other types of organic remains, such as insects, and animal remains. Under certain conditions, the decomposition of the latter (in the absence of oxygen) is inhibited.

Peat formed in very wet conditions accumulates faster, and is less decomposed, than that in drier places. This allows climatologists to use peat as an indicator of climatic change. The composition of peat can also be used to reconstruct ancient ecologies by examining the types and quantities of its organic constituents.

Under the proper conditions, peat is the earliest stage in the formation of coal. The coal measures of the Pennsylvanian period were laid down in a gigantic tropical river basin, and later squeezed and heated to form the metamorphic rock we call 'coal'.

Most modern peat bogs formed in high latitudes after the retreat of the glaciers at the end of the last ice age some 9,000 years ago. They usually grow slowly, at the rate of about a millimetre per year.

The peat in the world's peatlands has been forming for 360 million years and contains 550 Gigatonnes of carbon.

Uses

Peat is harvested as an important source of fuel in certain parts of the world. By volume, there are about 4 trillion m³ of peat in the world covering a total of around 2% of global land area (about 3 million km²), containing about 8 billion terajoules of energy.

Peat is soft and easily compressed. Under pressure, water in the peat is forced out. Upon drying, peat can be used as a fuel. It has industrial importance as a fuel in some countries, such as Ireland and Finland, where it is harvested on an industrial scale. In many countries, including Ireland and Scotland, where trees are often scarce, peat is traditionally used for cooking and domestic heating. Stacks of drying peat dug from the bogs can still be seen in some rural areas.

Peat's insulating properties make it of use to industry.

Peat fires are used to dry malted barley for use in Scotch whisky distillation. This gives Scotch whisky its distinctive smoky flavour, often called "peatiness".

Although peat has many uses for humans, it also presents problems. When dry, it can be a major fire hazard, as peat fires can burn almost indefinitely (or at least until the fuel is exhausted). Peat fires can even burn underground, reigniting after the winter, provided there is a source of oxygen. Peat deposits also pose major difficulties to builders of structures, roads, and railways, as they are highly compressible under even small loads. When the West Highland Line was built across Rannoch Moor in western Scotland, its builders had to float the tracks on a mattress of tree roots, brushwood and thousands of tons of earth and ashes.

Images for kids

Peat gatherers at Westhay, Somerset Levels in 1905
Peat stacks and cutting at Westhay, Somerset Levels
Harvesting the peat at Westhay, Somerset Levels
Peat extraction in East Frisia, Germany
Worked bank in blanket bog, near Ulsta, Yell, Shetland Islands
Falkland Islanders shovelling peat in the 1950s
Peat fire
Industrial milled peat production in a section of the Bog of Allen in the Irish Midlands: The 'turf' in the foreground is machine-produced for domestic use.
The Toppila Power Station, a peat-fired facility in Oulu, Finland
Shatura Power Station. Russia has the largest peat power capacity in the world
The Bor Peat Briquette Factory, Russia
Peat hags at the start of Allt Lagan a' Bhainne tributary on Eilrig
Increase, and change relative to previous year, of the atmospheric concentration of carbon dioxide.
Smoke and ozone pollution from Indonesian fires, 1997.