Video shot by Allen Fraser on 20 January 2005. Maximum wave height ~8 m after a night of up to Gale Force 10 winds. Cliff top here is at ~20 m asl.
"It is winter! The voice of the tempest is heard - no other sound. The sea birds are cowering in their rocky homes - the fisherman has sought the shelter of his hut - the cattle have fled inland. The blinding spray is sent far over the Villions - the waves of the might Atlantic are hurrying towards the iron-bound coast. See that tall billow! It rises to the skies - now the noise of thunder it falls upon the Grind, uptearing and upheaving vast masses of rock, which it carries like so many pebbles, to the savage shore behind, where they rest with the spoils of other storms, a shapeless heap thrown together by the hands of Titans." Andrew McCrae, 1860
Allen Fraser at Da Grind in May 1993. Note the abundance of fresh debris and the impact marks on the rocks. This area in front of the pond has suffered further erosion in recent years.
The seaward ridge, truncated by erosion since 1961
The ridges in around 1900. Image from the Shetland Museum Archive
"The most sublime scene is where a mural pile of porphyry, escaping the process of disintegration that is devastating the coast, appears to have been left as a sort of rampart against the inroads of the ocean. The Atlantic, when provoked by wintry gales, batters against it with all the force of real artillery- the waves having, in their repeated assaults, forced for themselves an entrance. This breach, named the Grind of the Navir, is widened every winter by the overwhelming surge, that, finding a passage through it, separates large stones from its sides, and forces them to a distance of 180 feet. In two or three spots the fragments which have been detached are brought together in immense heaps, that appear as an accumulation of cubical masses, the product of some quarry." Hibbert-Ware (1822)
Grind of the Navir
Significance: a unique site where the continuing erosion of a headland can be documented and dated, with active cliff-top boulder beach ridges
The place name for this remarkable headland translates roughly to "The Gateway of the Borer", a reference to the window that The Grind provides to the Atlantic between its twin bastions and to the way in which storm waves thunder through the portal.
Aerial image courtesy of Tammy Gifford of Bond Helicopters
The Grind shows a remarkable array of features. The staircase gateway allows the funnelling of storm waves which are thrown forward as fast-moving green water. The velocity of the water is sufficient to quarry blocks of ignimbrite from the area around the pond and to transport them to the beach ridges beyond. It is unusual, to say the least, to find storm beaches at 15 m above sea level and these ridges are up to 3.5 m high and include blocks up to 3 m long. The most recently moved blocks are on the seaward face of the first ridge. Many were moved in the great storms of 1992 and 1993; a few have moved since. The second and third ridges to landward have a scatter of fresh blocks but include large numbers of blackened and lichen-covered blocks. Comparison with photos held by the Shetland Museum shows that the base of these ridges have been stable for the last century. The storms of the early nineties achieved significant work at The Grind - the fresh scars from block removal are still clear in the notch on the seaward end of the pond - but is clear that waves have been removing blocks from the area of the pond for at least a century. Fresh scars on the northern bastion indicate that large slabs were lost in 1993 - this together with the opening of the tunnel and geo to landward suggests that The Grind may suffer major changes in major storms in the 21st century.
The Grind from the sea. Photo courtesy of Ronnie Johnston