EGD or Upper Endoscopy Procedure. The device used during an EGD procedure is called a flexible endoscope. It is tubular in shape and is very similar to the colonoscope that gastroenterologists use to examine a patientâs colon during a colonoscopy procedure, just thinner in diameter.
What causes ocean currents? Ocean currents result from two processes - the action of wind on the surface of the water, and from variation in water temperature that causes movement- a process known as convection. Convection occurs because the oceanic waters heat up becoming less dense.
Ocean tides are caused by the gravitation of the Moon. Currents can be formed by the flow of tidal water around the continental plates, or by a difference in water temperature between large ocean areas. Surface waves are caused by the wind. Abnormal waves can be created by the tectonic movement of plates around and under the ocean floor (tsunamis).