The coldest average temperature in Scottsdale is December at 54.2 degrees. The most monthly precipitation in Scottsdale occurs in August with 1.5 inches. The Scottsdale weather information is based on the average of the previous 3-7 years of data.
Divergent boundaries within continents initially produce rifts which eventually become rift valleys. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges. Divergent boundaries also form volcanic islands which occur when the plates move apart to produce gaps which molten lava rises to fill.
Divergent plate boundaries usually occur deep in the oceans. The mid-oceanic ridges are an example of this type of volcanic action. Occasionally, as is the case with Iceland, oceanic ridges rise above the surface of the ocean. Contrarily, convergent plate movement causes more visible volcanic action. Famous volcanoes, such as Vesuvius or Mount St. Helens, were caused by converging tectonic plates. In a process known as subduction, an oceanic plate collides with, and slides under, a continental plate.