Editing Geography of the United States (section)

===Geologic===
The West Coast of the continental United States makes up part of the [[Pacific Ring of Fire]], an area of heavy tectonic and volcanic activity that is the source of 90% of the world's earthquakes.<ref>{{Cite web |title=Cool Earthquake Facts {{!}} U.S. Geological Survey |url=https://www.usgs.gov/programs/earthquake-hazards/cool-earthquake-facts#:~:text=The%20%E2%80%9CRing%20of%20Fire%E2%80%9D%20also,the%20world's%20earthquakes%20occur%20there. |access-date=2023-09-30 |website=www.usgs.gov}}</ref> The American Northwest sees the highest concentration of active volcanoes in the United States, in [[Washington (state)|Washington]], [[Oregon]] and [[northern California]] along the [[Cascade Mountains]]. There are several active volcanoes located in the islands of Hawaii, including Kilauea in ongoing eruption since 1983, but they do not typically adversely affect the inhabitants of the islands. There has not been a major life-threatening eruption on the Hawaiian Islands since the 17th century. Volcanic eruptions can occasionally be devastating, such as in the [[1980 eruption of Mount St. Helens]] in Washington.

The Ring of Fire makes [[California]] and southern [[Alaska]] particularly vulnerable to [[earthquake]]s. Earthquakes can cause extensive damage, such as the [[1906 San Francisco earthquake]] or the 1964 [[Good Friday earthquake]] near [[Anchorage, Alaska]]. California is well known for seismic activity and requires large structures to be [[Earthquake resistant structures|earthquake resistant]] to minimize loss of life and property.<ref>{{cite web| url = https://earthquake.usgs.gov/learn/publications/saferstructures/| url-status = dead| archive-url = https://web.archive.org/web/20100511070408/http://earthquake.usgs.gov/learn/publications/saferstructures/| archive-date = 2010-05-11| title = Building Safer Structures}}</ref> Outside of devastating earthquakes, California experiences minor earthquakes on a regular basis.

There have been about 100 significant earthquakes annually from 2010 to 2012. Past averages were 21 a year. This is believed to be due to the deep disposal of wastewater from [[fracking]]. None have exceeded a magnitude of 5.6, and no one has been killed.<ref>{{cite news | first=Dan | last=Vergano | title=Study:Earthquake increase tied to energy boom | url=https://www.usatoday.com/story/news/nation/2013/07/11/injection-induced-earthquakes/2508499/| newspaper=[[The Burlington Free Press]] | location=[[Burlington, Vermont]] | pages= 10A | date=July 12, 2013 | access-date=July 14, 2013}}</ref>