Vasa Loch is a

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') a ...

in southwestern

Shapinsay Shapinsay (, sco, Shapinsee) is one of the Orkney Islands off the north coast of mainland Scotland. There is one village on the island, Balfour, from which roll-on/roll-off car ferries sail to Kirkwall on the Orkney Mainland. Balfour Castle, ...

Orkney Islands Orkney (; sco, Orkney; on, Orkneyjar; nrn, Orknøjar), also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) north ...

. (Ordnance, 2002) This water body has been shown on early maps of the island in a very similar shape and size to its current geometry, separated from the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

by a narrow strip of

raised beach A raised beach, coastal terrace,Pinter, N (2010): 'Coastal Terraces, Sealevel, and Active Tectonics' (educational exercise), from 2/04/2011/ref> or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin,P ...

.(Masters, 1840) Vasa Loch is fed by small rivulets and upland springs that rise on the western part of the island's western spur. pH levels of the

loch ''Loch'' () is the Scottish Gaelic, Scots language, Scots and Irish language, Irish word for a lake or sea inlet. It is Cognate, cognate with the Manx language, Manx lough, Cornish language, Cornish logh, and one of the Welsh language, Welsh w ...

are strongly

alkaline In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as ...

, in the range of 10.15. (Hogan, 2006)

Geology

The particular

landform A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, ...

associated with Vasa Loch is an ''

ayre Ayre ( ; gv, Inver Ayre) is one of the six sheadings of the Isle of Man. It is located in the north of the island (part of the traditional ''North Side'' division) and consists of the three historic parishes of Andreas, Bride and (Kirk Christ ...

'', derived from the

Old Norse Old Norse, Old Nordic, or Old Scandinavian, is a stage of development of North Germanic languages, North Germanic dialects before their final divergence into separate Nordic languages. Old Norse was spoken by inhabitants of Scandinavia and t ...

word used to depict a lake which is only separated by a narrow strip of low-lying land from the sea itself.(Shapinsay)

Notes

*Ordnance Survey Map, Landranger, United Kingdom, 1:50,000 (2002) * G.T, Masters, ''Orkney, Approaches to Kirkwall'', HMS official survey map, 1840-1843 *C.M Hogan, ''Natural History of the Orkney Islands'' (2006)
Shapinsay Island, Orkney

Geology

Notes

See also