Editing Santa Rosa, California (section)

===Seismicity===
Santa Rosa lies atop the [[Healdsburg Fault|Healdsburg-Rodgers Creek segment]] of the [[Hayward Fault|Hayward-Rodgers Creek Fault System]]. The Working Group on California Earthquake Probabilities estimated a minimum 27 percent chance of a magnitude 6.7 or greater earthquake on this segment by 2037.<ref name=quake>{{cite web |url=http://www.ci.healdsburg.ca.us/Modules/ShowDocument.aspx?documentid=411 |title=Healdsburg 2030 General Plan Update – Revised Draft Environmental Impact Report – IV.G. Geology/Soils |publisher=City of Healdsburg, California |page=IV.G–11 |date=August 20, 2007 |access-date=September 10, 2014 }}{{dead link|date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

On November 21, 2005, the [[United States Geological Survey]] released a map detailing the results of a new tool that measures ground shaking during an earthquake. The map determined that the [[1906 San Francisco earthquake]] was most powerful in an area between Santa Rosa and what is now [[Sebastopol, California|Sebastopol]], causing more damage in Santa Rosa (for its size) than any other city affected.<ref name="1906_quake">{{cite press release | title=USGS Produces New Map Showing Detailed Ground Shaking in Great San Francisco Old Maps, even Old Cemeteries, Provide New Clues for Modern Intensity Tool | url=http://www.usgs.gov/newsroom/article.asp?ID=693 | publisher = United States Geoloogical Survey | date=April 14, 2005 |access-date=September 9, 2014}}</ref>

On October 1, 1969, [[1969 Santa Rosa earthquakes|two earthquakes]] of magnitudes 5.6 and 5.7 shook Santa Rosa, damaging about 100 structures. They were the strongest quakes to affect the city since 1906. The epicenters were about {{convert|2|mi|km|spell=in}} north of Santa Rosa.