hiccup hicÂ·cup or hicÂ·cough (hÄ­k'Ép) n. A spasm of the diaphragm causing sudden inhalation interrupted by spasmodic closure of the glottis, producing a characteristic noise.
Ancient Convergent Plate Boundary-Appalachian Mountain Range. The range is mostly located in the United States but extends into southeastern Canada, forming a zone from 100 to 300 mi (160 to 480 km) wide, running from the island of Newfoundland 1,500 mi (2,400 km) southwestward to Central Alabama in the United States.
The Earthâs crust and upper mantle (lithosphere) is divided into many plates, which are in constant motion. Where plate edges meet and one plate may slide past another, one plate may be driven beneath another (subduction). Upwelling volcanic material pushes plates apart at mid-ocean ridges. Continental plates are made of less dense rocks (granites) that are thicker than oceanic plates (basalts) and thus, ârideâ higher than oceanic plates.