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 Currents. Ocean currents are a convection system caused by thermal gradients in the oceans and the rotation of the earth. Unlike tides they are almost constant in their direction and their velocity fluctuates only by small amounts according to the seasons of the year.