Editing Yellowstone National Park (section)

=== Earthquakes ===
[[File:State Highway 287 slumped into Hebgen Lake.jpg|thumb|Infrastructure damage at [[Hebgen Lake]] due to the 7.2 magnitude [[1959 Hebgen Lake earthquake|earthquake of 1959]]]]
Yellowstone experiences thousands of small earthquakes every year, virtually all of which are undetectable to people. About 2/3 of the earthquakes occur in an area between Hegben Lake and the Yellowstone Caldera along a buried fracture zone left from the 2.1 mya eruption.<ref name="Lowenstern">{{cite journal |last1=Lowenstern |first1=Jacob B. |last2=Smith |first2=Robert B. |last3=Hill |first3=David P. |title=Monitoring Super-Volcanoes: Geophysical and Geochemical Signals at Yellowstone and Other Large Caldera Systems |journal=Philosophical Transactions: Mathematical, Physical and Engineering Sciences |date=August 15, 2006 |volume=364 |issue=1845 |pages=2055–2072 |doi=10.1098/rsta.2006.1813 |pmid=16844648 |bibcode=2006RSPTA.364.2055L |s2cid=12160214 }}</ref>

There have been six earthquakes with at least [[Moment magnitude scale|magnitude]] 6 or greater in historical times, including the 7.2‑magnitude [[1959 Hebgen Lake earthquake|Hebgen Lake earthquake]] which occurred just outside the northwest boundary of the park in 1959.<ref>[https://earthquake.usgs.gov/earthquakes/eventpage/iscgem882673/executive "M 7.2 – Hebgen Lake, Wyoming Earthquake"] {{Webarchive |url=https://web.archive.org/web/20181128215558/https://earthquake.usgs.gov/earthquakes/eventpage/iscgem882673/executive |date=November 28, 2018 }}. ''earthquake.usgs.gov''. United States Geological Survey via the International Seismological Centre. Retrieved November 28, 2018.</ref> This quake triggered a huge [[landslide]], which caused a partial dam collapse on Hebgen Lake; immediately downstream, the [[sediment]] from the landslide dammed the river and created a new lake, known as [[Quake Lake|Earthquake Lake]]. Twenty-eight people were killed, and property damage was extensive in the immediate region. The earthquake caused some geysers in the northwestern section of the park to erupt, large cracks in the ground formed and emitted steam, and some hot springs that normally have clear water turned muddy.<ref name="earthquake"/> The stress created in the fracture zone by this quake is theorized to be responsible for the current quake activity in the northwestern section of Yellowstone.<ref name="Lowenstern" /> A 6.1‑magnitude earthquake struck inside the park on June 30, 1975, but the damage was minimal.

For three months in 1985, 3,000 minor earthquakes were detected in the northwestern section of the park, during what has been referred to as an [[earthquake swarm]], and has been attributed to minor subsidence of the Yellowstone caldera.<ref name="volcanic"/> Beginning on April 30, 2007, 16 small earthquakes with magnitudes up to 2.7 occurred in the Yellowstone Caldera for several days. These swarms of earthquakes are common, and there have been 70 such swarms between 1983 and 2008.<ref name="swarms">{{cite news |title=More Than A Dozen Earthquakes Shake Yellowstone |publisher=KUTV News |date=May 6, 2007 |url=http://kutv.com/national/local_story_126175405.html |access-date=May 7, 2007 |archive-url=https://web.archive.org/web/20070526111246/http://kutv.com/national/local_story_126175405.html |archive-date=May 26, 2007 }}</ref> In December 2008, over 250 earthquakes were measured over four days under Yellowstone Lake, the largest measuring a magnitude of 3.9.<ref>{{cite web |url=http://volcanoes.usgs.gov/yvo/activity/archive/2008.php |title=Archive of Yellowstone Updates for 2008 |publisher=Yellowstone Volcanic Observatory |access-date=December 31, 2008 |url-status=live |archive-url=https://web.archive.org/web/20090123054301/http://volcanoes.usgs.gov/yvo/activity/archive/2008.php |archive-date=January 23, 2009 }}</ref> In January 2010, more than 250 earthquakes were detected over two days.<ref>{{cite news |url=http://www.denverpost.com/ci_14216212 |title=Yellowstone hit by swarm of earthquakes |work=[[The Denver Post]] |date=January 18, 2010 |url-status=live |archive-url=https://web.archive.org/web/20100121133535/http://www.denverpost.com/ci_14216212#ixzz0d0TCeanj |archive-date=January 21, 2010 }}</ref> Seismic activity in Yellowstone National Park continues and is reported hourly by the Earthquake Hazards Program of the U.S. Geological Survey.<ref>{{cite web |url=https://earthquake.usgs.gov/eqcenter/recenteqsus/Maps/special/Yellowstone.php |publisher=United States Geological Survey |title=Latest Earthquakes – US " Yellowstone Region |url-status=dead |archive-url=https://web.archive.org/web/20081206022248/http://earthquake.usgs.gov/eqcenter/recenteqsus/Maps/special/Yellowstone.php |archive-date=December 6, 2008 }}</ref>

On March 30, 2014, a magnitude 4.8 earthquake struck almost the very middle of Yellowstone near the Norris Basin at 6:34&nbsp;am; reports indicated no damage. This was the largest earthquake to hit the park since February 22, 1980.<ref>{{cite web |url=http://guardianlv.com/2014/03/4-8-magnitude-earthquake-hits-yellowstone-national-park/ |title=4.8 Magnitude Earthquake Hits Yellowstone National Park |publisher=Liberty Voice |date=March 30, 2014 |access-date=March 31, 2014 |url-status=live |archive-url=https://web.archive.org/web/20140331011654/http://guardianlv.com/2014/03/4-8-magnitude-earthquake-hits-yellowstone-national-park/ |archive-date=March 31, 2014 }}</ref>