Geoscience Reference
In-Depth Information
It is only when standing on the tower of the Cathedral at Milan, or on the summit of the
Superga, near Turin, looking across the great plain towards the distant mountains rising
abruptly from it, that one can realize the strength and volume of the torrents which must
have issued from the Alpine valleys at this epoch (Harmer
1901
).
One of the effects of strong winds associated with stormy weather over the North
Sea is to agitate the water to a considerable depth and to scour the sea-bed, causing
molluscan shells to be shifted towards the opposing coast. Harmer learned from a
colleague in Great Yarmouth that on 12 or 13 December 1899, the local beach, on
which shells were not usually found, was partly covered by them. By referring to
the Daily Weather Reports published by the Meteorological Office, Harmer found
that a spell of strong to gale force east to southeasterly winds had occurred from 7
to 9 December which resulted in the shells being thrown up on the beach.
He used this meteorological situation, associated with a blocking anticyclone
over Scandinavia as an analogue for the type of circulation pattern which, he
suggested, had frequently occurred during the late Pliocene leading to the for-
mation of a succession of littoral beds, which, in the case of the Red Crag, attained
a thickness of up to 6 m (20 ft) in the cliffs of East Anglia.
In summary, Harmer's hypothesis suggested that anomalous circulation patterns
associated with current weather extremes over the British Isles may have been the
norm in past geological periods such as the late Pliocene epoch when shelly
marine sands, collectively known as Crag deposits had massively accumulated
near the western shoreline of the Crag Sea, due to the successive drifting of the
material upon the beach by strong and persistent easterly winds.
In 1925, 2 years after Harmer's death, his second key paper on the meteoro-
logical conditions that prevailed during the Pleistocene epoch, 'Further Remarks
on the Meteorological Conditions of the Pleistocene Epoch', was presented by the
pioneering climatologist with expertise in geology, Dr Charles E.P. Brooks
(1888-1957) at a meeting of the Royal Meteorological Society held on Wednes-
day, 20 May, at the Society's Rooms, 49 Cromwell Road, South Kensington,
Mr J.S. Dines, Vice-President, being in the Chair.
Brooks explained that this paper was essentially an amplification and extension
of the views first put forward by Harmer in his 1901 paper, 'The influence of the
winds upon climate during the Pleistocene Epoch: A palaeometeorological
explanation of some geological problems'. Harmer's son, Sir Sidney Harmer, who
attended the meeting, explained that he had found the draft manuscript in his
father's collection of papers and was greatly indebted to Brooks for preparing the
article for publication (Brooks
1970
).
In his introductory note, Brooks stated that the manuscript had been left by
Harmer in an almost complete form. Although some of the maps had not been
drawn and the text had not been finally revised, the material was otherwise
complete. However, on reading it through, Brooks found that a certain problem
arose which he felt should be addressed before publication.
Brooks stated that while most of Harmer's deductions were still valid in the
light of current knowledge, in one respect they have proved to be erroneous. The
hypothesis of alternating glaciations in Europe and North America, which was
