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 can be generated by wind, density differences in water masses caused by temperature and salinity variations, gravity, and events such as earthquakes. Currents are cohesive streams of seawater that circulate through the ocean. Some are short-lived and small, while others are vast flows that take centuries to complete a circuit of the globe.