Lochearnhead village is situated at the western end of the Loch Earn. Loch Earn (Scottish Gaelic, Loch Eire/Loch Éireann) is a freshwater loch in the central highlands of Scotland, in the districts of Perth and Kinross and Stirling. The name is thought to mean "Loch of Ireland", and it has been suggested that this might derive from the time when the Gaels were expanding their kingdom of Dál Riata. It can be located on Satnav from postcodes including PH6 2NL.
Loch Earn is unusual in that it has its own apparent 'tidal system', or seiche, caused by the action of the prevailing wind blowing along the loch. This wind pressure on the surface causes the water level to build up at one end of the loch. As with all damped mechanical systems, applied pressure can result in an oscillation, and the water will return to the opposite end of the loch over time. In the case of Loch Earn, this has a period of 16 hours and the effect can be measured, but is difficult to observe. The resulting currents can create complex turbulence patterns, as higher layers of warmer waters mix with the lower lying colder waters of the loch.
Other bodies of fresh water which experience this seiche effect include Lake Geneva, Lake Garda, the Great Lakes and Lake Baikal.
