大象传媒

Bidh seiche ann an Loch Nis bho 脿m gu 脿m. 鈥橲 e seiche facal 脿 Fraingis na h-Eilbheis. Tha e a鈥� coimhead coltach ri seiche ann an G脿idhlig. Ach chan eil e a鈥� ciallachadh craiceann beathaich. Tha e a鈥� ciallachadh tuinn mh貌ra ann an loch.

聽聽聽聽聽聽聽聽聽聽聽 Ch矛 sibh an aon se貌rsa rud anns an amar aig an taigh. Putaibh an t-uisge gu aon cheann dhen amar. Thig an t-uisge air ais a-rithist. Bidh e a鈥� luasgadh a-null 鈥檚 a-nall airson 霉ine.

聽聽聽聽聽聽聽聽聽聽聽 Ann an loch, bidh a鈥� ghaoth ag adhbharachadh seiche. Ach bidh crith-thalmhainn cuideachd ag adhbharachadh seiche. Uaireannan, bidh a鈥� chrith fad air falbh bhon uisge anns a bheil an seiche.

聽聽聽聽聽聽聽聽聽聽聽 Anns an Litir an t-seachdain sa chaidh, bha mi ag innse dhuibh mu Chrith-thalmhainn Mh貌r Lisbon. Bha sin ann an seachd ceud deug, caogad 鈥檚 a c貌ig (1755). Thug i buaidh air d霉thchannan eile anns an Roinn E貌rpa. Bha seiche ann an Loch Nis.

聽聽聽聽聽聽聽聽聽聽聽 Dh鈥櫭╥rich uachdar an locha gu 矛re 脿rd. Ann an Cille Chuimein, chaidh b脿ta a sguabadh 脿s an loch. Chaidh am b脿ta fh脿gail tioram air t矛r.

聽聽聽聽聽聽聽聽聽聽聽 Ach d猫 mu dheidhinn crithean ann an Inbhir Nis fh猫in? No anns a鈥� Ghleann Mh貌r? Tha sg脿ineadh chreagan an sin ris an canar 鈥淭he Great Glen Fault鈥�. Chan eil crithean-talmhainn a鈥� tachairt gu tric, ge-t脿. Tha sin fortanach oir tha mi fh矛n a鈥� fuireach ann an Inbhir Nis!

聽聽聽聽聽聽聽聽聽聽聽 Mar as trice, bidh meadhan na crithe p矛os a-mach 脿s a鈥� bhaile. Ach corra uair bidh meadhan na crithe faisg air a鈥� bhaile.

聽聽聽聽聽聽聽聽聽聽聽 鈥橲 iad an d脿 eisimpleir as fhe脿rr dhiubh 鈥� an fheadhainn a thachair ann an ochd ceud deug is sia-deug (1816) agus ann an naoi ceud deug 鈥檚 a h-aon (1901). Tha na h-e貌laichean dhen bheachd gun robh meadhan na ciad t猫 siar air Inbhir Nis. Tha iad ag r脿dh gun robh meadhan na d脿rna t猫 ann an Dabhach Gairbheach. Tha sin d矛reach seachd cilemeatair a-mach 脿s a鈥� bhaile. Rinn na crithean sin beagan millidh ann an Inbhir Nis. Ach cha do dh鈥檉huiling Inbhir Nis mar a dh鈥檉huiling Lisbon.

There is a seiche in Loch Ness from time to time. Seiche is a word from Swiss French. It looks like seiche in Gaelic. But it doesn鈥檛 mean an animal鈥檚 hide. It means big waves in a loch.

聽聽聽聽聽聽聽 You鈥檒l see the same sort of thing in the bath at the house. Push the water to one end of the bath. The water comes back again. It oscillates for a period of time.

聽聽聽聽聽聽聽 In a loch, the wind causes a seiche. But an earthquake also causes a seiche. Sometimes the quake is a long way from the water in which the seiche occurs.

聽聽聽聽聽聽聽 In the Litir last week, I was telling you about the Great Lisbon Earthquake. That was in 1755. It affected other countries in Europe. There was a seiche in Loch Ness.

聽聽聽聽聽聽聽 The surface of the loch rose to a high level. In Fort Augustus, a boat was swept from the loch. The boat was left [high and] dry on [the] land.

聽聽聽聽聽聽聽 But what about quakes in Inverness itself? Or in the Great Glen? There is a geological fault there called 鈥淭he Great Glen Fault鈥�. But earthquakes don鈥檛 happen often. That鈥檚 fortunate because I myself live in Inverness!

聽聽聽聽聽聽聽 Usually, the quake鈥檚 epicentre is a good bit out of the town. But occasionally the quake鈥檚 epicentre is close to the town.

聽聽聽聽聽聽聽 The best two examples of them are the ones that happened in 1816 and in 1901. Experts reckon that the epicentre of the first one was west of Inverness. They say that the epicentre of the second one was in Doch-garroch. That鈥檚 just seven kilometres outside the town. Those quakes did a bit of damage in Inverness. But Inverness didn鈥檛 suffer in the way Lisbon suffered.