Archaeology
Pollen records
Volcanic ash
As well as pollen and spores, dust also settles on the peat
bog. This may not seem very exciting, unless the dust is very
distinctive such as ash from erupting volcanoes, otherwise known
as tephra. Volcanic ash was frequently blown over Ireland from
volcanic eruptions in Iceland and preserved within the peat
bogs. Scientists can identify the minerals within the ash like
a volcanic fingerprint, and can link them to the volcano they
came from. For eruptions that have occurred since the advent
of historical records, this often allows scientists to pinpoint
the actual year of the eruption, and therefore a precise date
for the ash layer in the peat bog.
| Eruption of Stromboli
volcano in Italy |
|
Volcanic shard from the
Hekla 4 eruption, which took place in Iceland 4300 years
ago |
 |
|
 |
It has previously been difficult to date the most recent peat,
but new tephra studies have made this easier. Volcanic ash from
historic eruptions in Iceland has been detected at lowland sites.
Ash in some peat bogs is known to have originated from the eruptions
of Hekla in 1104 and 1510 with further finds of ash from the
eruption of Oraefajokull in 1362. These volcanic events often
led to cooler, wetter periods of weather in Europe, resulting
in bad growing seasons and even famine, all of which is recorded
in the peat. As with all such studies on peat, it is only possible
to get this amount of information from it if the bog surfaces
remain intact.
Using the peat record to understand the future
We have seen that the peat contains the history of climate
change and the impact of people in Ireland. We know that people
will bring about further changes to the world in the future.
What we do not know is how quickly or how dramatically those
changes will happen, nor how quickly we will be able to adapt
to new environmental conditions. However, as we have seen we
already have this sort of historical information in the peat
record. Not only is it important to conserve peatlands for the
plants and animals that live there, it is also important to
keep them as we would any library containing valuable knowledge.
Continuing to study peat as a record of the past will help us
understand what the future may have in store for us.
