Eardrum within two to four weeks. The prognosis becomes more guarded as the force of injury increases. The pressure of fluid in an infected middle ear onto the eardrum may cause it to rupture. Usually this consists of a small hole (perforation), which allows fluid to drain out. If this does not occur naturally, a myringotomy (tympanotomy, tympanostomy) can be performed. A myringotomy is a surgical procedure in which a tiny incision is created in the eardrum to relieve pressure caused by excessive buildup of fluid, or to drain pus from the middle ear. The fluid or pus comes from a
River incision (Jansen 2006), removing this armoring layer of gravel, boulders, etc. exposes the channel bed to the erosive force of the water. “On the Russian River near Healdsburg, California, instream pit mining in the 1950s and 1960s caused channel incision in excess of 3-6 m over an 11-km length of river” (Kondolf et. al. 2002). Tectonics play an important role in shaping landscapes and rivers, and tectonic uplift and river incision go hand in hand. Over geologic time, as mountains rise higher, water erodes deep gorges and channels, dissecting the landscape. In some instances, such as the Sierra Nevada mountains of