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Old Man of Hoy
The Old Man of Hoy is Britain's tallest and probably most photographed sea
stack. At 137m high and only about 30m wide at its base, this imposing rectangular
stack has been carved from layer upon layer of Old
Red Sandstone (Devonian) rocks. The shaping of the stack can be traced
back through the centuries through paintings and maps. In 1750, the Old Man
was depicted as a headland, but by the 1820's stormy seas had carved the rock
into a stack and arch - two legs gave the Old Man his name. A severe storm
however, washed away one of the legs to leave the pillar that remains - for
now!
The Old Man of Hoy - Orkney.
Image provided by Scottish Natural
Heritage
The rocks of the Old Man are composed of alternating layers of soft sandstones
and more resistant flagstones of the Upper Old Red Sandstone. These rocks lie
over a base of dark Old Red Sandstone basalt lava flows. Jointing and faulting
in the sedimentary rocks occurs in rectangular form and this is reflected in
the blocky shape of the Old Man and surrounding cliffs. The stack stands about
60m away from the cliffs; in between lies a pile of debris which is the remains
of the roof of the arch that collapsed.
The future will almost certainly bring the total demise of the Old Man. There
is already a large 40m crack running vertically from the top of the stack which
threatens its upper reaches. Waves will also continue to erode the base of
the stack until the entire pillar collapses.
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