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.
o Asthenosphere has convective motion. o This motion pushes lithosphere plates around. Plate tectonics is the movement of large portions of the crust. The movement is caused by magma squeezing out along the mid-oceanic ridges pushing the plates apart in a process called seafloor spreading.