a branch of the Indo-European family of languages, including especially Irish, Scottish Gaelic, Welsh, and Breton, which survive now in Ireland, the Scottish Highlands, Wales, and Brittany. adjective. 2. of the Celts or their languages.
Movement of tectonic plates-higher. Volcanoes, mountains and earthquakes occur at the edges of tectonic plates-their creation depends on the direction the plates are moving.
A: The three primary causes for tectonic plate movement are the convection of material in the mantle, gravity and the rotation of the planet. These forces cause each of the seven major plates and numerous other microplates to move independently of the others at a rate of a few centimeters per year. Know More.