Fróðskaparrit - 01.01.1998, Síða 149

155
Holocene climatic Vanability m the North
Atlantic Region as shown by Peat Bog
Records
Umskifti í holosena veðurlagnum í norðuratlantsøkinum, sum tað sæst
av torvmýruroyndum
JeffJ. Blackford
Department of Geography, Queen Mary and Westfield College, University of London, UK. E1 4NS.
Phone: +44 171 975 5400, fax: +44 181 981 6276, e-mail:
Úrtak
Torvmýruroyndir kunnu vera ein kelda til upplýsingar
um proxyveðurlagið í tí holosena tíðarskeiðinum.
Nýggjar kanningar hava víst, at brádligar veðurlags-
broytingar koma fyri við jøvnum millumbilum; hetta
boðar frá reglubundnum endurtøkum og møguliga sam-
bandi við umskiftingar í sólini. Ivamál eru kortini, ser-
stakliga í sambandi við ávirkan frá menniskjum, mót-
sigandi úrslitum ymsastaðni frá og óneyvum dagfesting-
um. Uppskot verður lagt fram um eina arbeiðshypotesu,
til gransking í framtíðini.
Abstract
Peat bog records can provide proxy climate records for
the Holocene period. Recent studies have shown abrupt
climatic changes at certain recurring points in time, evi-
dence of periodicity and a possible link to solar vari-
ability. Problems remain, however, notably accounting
for human impact, inconsistent results from different
sites and dating imprecision. A testable working hy-
pothesis is suggested for future research.
Introduction
Evidence from raised bogs and blanket
mires, in the form of plant macrofossil as-
semblages, peat humification analyses and
microfossil content, allow inferences to be
made about past mire hydrological condi-
tions. These can then be combined on a re-
JJ.Blackford@qmw.ac.uk
gional basis to infer palaeoclimatic changes
(Blackford, 1993). The aim of this paper is
to outline the overall trends shown by pub-
lished palaeoclimatic evidence obtained
from peat bogs around the North Atlantic
region (coastal areas of north west Europe),
and propose a working hypothesis for fu-
ture investigations.
Research into the link between past cli-
matic changes and peat bogs records has
been conducted since the last century (see
reviews by Barber 1981; 1982 and Black-
ford, 1993). By the early twentieth century,
an apparent pattern had emerged, that of the
Blytt-Semander model, which attempted to
subdivide the Holocene into broad periods
of distinct climatic characteristics. The
terms used- Boreal, Atlantic, Sub-Boreal
and Sub-Atlantic- are still found in the lit-
erature today, despite several studies that
have shown the scheme to be, at best, over-
simplified (Smith, 1981).
Peat-based palaeoclimatic studies have
progressed in a number of ways over the
last three decades. The introduction of ra-
diocarbon dating allowed more precise
Fróðskaparrit 46. bók 1998: 155-162