2020 Salt Lake City earthquake: Difference between revisions

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{{expand section|date=March 2020}}
{{expand section|date=March 2020}}
More than 50 [[aftershock]]s were recorded within two hours of the main tremor,<ref name="Deseret">{{cite news|last1=Reavy|first1=Pat|url=https://www.deseret.com/utah/2020/3/18/21184993/5-7-earthquake-hits-near-magna-shakes-entire-wasatch-front|title=5.7 earthquake hits near Magna, shakes entire Wasatch Front|date=March 18, 2020|work=Deseret News|accessdate=March 18, 2020|publisher=Deseret News|location=Salt Lake City, Utah}}</ref> with over 200 aftershocks associated with the earthquake, however most were weaker than 2.0 magnitude. The strongest reported was a magnitude 4.6 at 1:12pm [[Mountain Time|MDT]], March 18. <ref name="sltrib Utah earthquake">{{cite news |title=Utah earthquake: Big aftershock hits, acid plume no longer dangerous, emergency declarations issued |url=https://www.sltrib.com/news/2020/03/18/earthquake-hits-utahs/ |accessdate=18 March 2020 |work=The Salt Lake Tribune}}</ref>
More than 50 [[aftershock]]s were recorded within two hours of the main tremor,<ref name="Deseret">{{cite news|last1=Reavy|first1=Pat|url=https://www.deseret.com/utah/2020/3/18/21184993/5-7-earthquake-hits-near-magna-shakes-entire-wasatch-front|title=5.7 earthquake hits near Magna, shakes entire Wasatch Front|date=March 18, 2020|work=Deseret News|accessdate=March 18, 2020|publisher=Deseret News|location=Salt Lake City, Utah}}</ref> with over 200 aftershocks associated with the earthquake, however most were weaker than 2.0 magnitude. The strongest reported was a magnitude 4.6 at 1:12pm [[Mountain Time|MDT]], March 18. <ref name="sltrib Utah earthquake">{{cite news |title=Utah earthquake: Big aftershock hits, acid plume no longer dangerous, emergency declarations issued |url=https://www.sltrib.com/news/2020/03/18/earthquake-hits-utahs/ |accessdate=18 March 2020 |work=The Salt Lake Tribune}}</ref>
The [[United States Geological Survey]] forecast that the chance of at least 2 magnitude 3.0-4.9 [[aftershock]]s were highly likely, with a 99% chance, and a magnitude 5.0-5.9 aftershock had around a 13% chance of occurring. The chance of an aftershock greater than 5.9 magnitude was also assessed as "possible", but very unlikely.<ref>{{cite web |title=M 5.7 - 6km NNE of Magna, Utah 2020-03-18 13:09:31 (UTC)40.751°N 112.078°W11.9 km depth Aftershock Forecast |url=https://earthquake.usgs.gov/earthquakes/eventpage/uu60363602/oaf/commentary}}</ref>
The [[United States Geological Survey]] forecast that the chances of at least 2 magnitude 3.0-4.9 [[aftershock]]s were highly likely, with a 99% chance, and a magnitude 5.0-5.9 aftershock had around a 13% chance of occurring. The chance of an aftershock greater than 5.9 magnitude was also assessed as "possible", but very unlikely.<ref>{{cite web |title=M 5.7 - 6km NNE of Magna, Utah 2020-03-18 13:09:31 (UTC)40.751°N 112.078°W11.9 km depth Aftershock Forecast |url=https://earthquake.usgs.gov/earthquakes/eventpage/uu60363602/oaf/commentary}}</ref>


==Geology==
==Geology==

Revision as of 00:55, 24 March 2020

2020 Salt Lake City earthquake
2020 Salt Lake City earthquake is located in Utah
Salt Lake City
Salt Lake City
2020 Salt Lake City earthquake
UTC time2020-03-18 13:09:31
ISC event617799112
USGS-ANSSComCat
Local dateMarch 18, 2020 (2020-03-18)
Local time07:09 a.m. MDT
MagnitudeMw5.7
Depth11.7 km (7.3 mi)
Epicenter40°51′04″N 112°04′52″W / 40.851°N 112.081°W / 40.851; -112.081
FaultWasatch Fault
Areas affectedUtah, southern Idaho, eastern Nevada, western Wyoming
Max. intensityVIII (Severe)[1]
Aftershocks> 250+
Casualties0

At approximately 7:09 AM MDT on the morning of March 18, 2020, a 5.7 magnitude earthquake hit Salt Lake City, Utah, United States, with an epicenter 6 km (3.7 mi) north-northeast of Magna, Utah.[2] It was the state's strongest earthquake since the 1992 St. George earthquake, and the strongest to occur near Salt Lake City since 1962, when a 5.0 earthquake struck.[3]

The earthquake occurred during the 2020 coronavirus pandemic, which had caused many residents to stay home from work or school to avoid infection.[4][5] As a result of the pandemic, Salt Lake City International Airport was also emptier than usual at the time of the earthquake.[4]

Earthquake

The earthquake caused power outages near Salt Lake City International Airport,[6] and a ground stop was enacted on the airport.[7] The control tower was evacuated, and passengers in terminals and concourses were moved onto buses. Cars on the TRAX light rail system were held at their nearest stations. Roughly 55,000 electricity customers lost power throughout the Salt Lake Valley.[6] Items were shaken off walls and shelves in homes and businesses, and bricks were shed off façades.[6] The Granite School District cancelled its planned events for the day to assess earthquake damage.[8]

Earthquakes of similar magnitude impact Utah approximately once every decade.[6] Intense shaking was felt in Downtown Salt Lake City,[9] and the earthquake was reportedly felt as far away as Wyoming and southern Idaho.[8][10] The report of a tremor related to the earthquake farthest from its epicenter occurred in Cokeville, Wyoming, over 110 miles (180 km) away from the epicenter.[11]

Aftermath

About an hour after the earthquake, media online began to spread rumors stating that another, much larger earthquake would occur in Salt Lake City following the original quake. Utah Emergency Management dismissed these claims on Twitter, stating that the original earthquake was likely the strongest.[12]

Aftershocks

More than 50 aftershocks were recorded within two hours of the main tremor,[9] with over 200 aftershocks associated with the earthquake, however most were weaker than 2.0 magnitude. The strongest reported was a magnitude 4.6 at 1:12pm MDT, March 18. [5] The United States Geological Survey forecast that the chances of at least 2 magnitude 3.0-4.9 aftershocks were highly likely, with a 99% chance, and a magnitude 5.0-5.9 aftershock had around a 13% chance of occurring. The chance of an aftershock greater than 5.9 magnitude was also assessed as "possible", but very unlikely.[13]

Geology

Salt Lake City lies at the eastern boundary of the Basin and Range Province. The major active fault zone is the normal Wasatch Fault that throws down to the west. The footwall (upthrown part) is formed by the Wasatch Range with part of the Great Basin lying in the hanging-wall (downthrown part), at one time filled by Lake Bonneville, with the Great Salt Lake forming the largest remnant. The fault zone is broken up into six segments that appear to rupture separately. Paleoseismic investigations indicate that 19 major earthquakes have occurred in the last 6,000 years along the fault system.[14]

Impacts

Injuries

Though some minor injuries occurred, no major injuries were reported as a result of the earthquake.[5]

Damage

The Salt Lake Temple's Moroni statue without trumpet.

After the earthquake, Utah Emergency Management said that serious damage was not expected, but there were reports of minor damage.[15] Bricks fell off some buildings.[5]

The Salt Lake Temple was undergoing a seismic upgrade at the time of the earthquake, and sustained minor damage. The Angel Moroni statue that sits atop the highest spire lost its trumpet following the earthquake. Some stones were displaced as well. The construction crews working on the seismic upgrade were sent home.[15]

The historic Rio Grande Depot, St. Mark's Episcopal Cathedral, and dozens of mobile homes in West Valley City were damaged.[5]

8,200 U.S. gallons (31,000 L) hydrochloric acid leaked from a tank at Kennecott Utah Copper's refinery in Magna due to the earthquake, which authorities said was confined to the facility and did not impact public safety.[16]

Radio station KMRI 1550 AM lost its transmitting tower located in West Valley City. The station was forced off air, and another station at the site KIHU 1010 AM was operating at reduced power. Both transmitters were very near the epicenter. KMRI filed for special temporary authority to go silent due to the collapse.[17][18]

Power outages

Around 50,000 power outages were reported from customers across northern Utah following the earthquake from several damaged power lines, according to Rocky Mountain Power. The number of outages was down to 10,000 by 1:38 PM MDT,[5] and down to 2,600 by the evening.

Pandemic response

The earthquake took place during the 2020 coronavirus pandemic in the United States. The day of the earthquake, Governor Gary Herbert said, "This is extremely bad timing, because we already have the coronavirus issue going on right now causing a lot of anxiety."[4]

The earthquake disrupted some of the public health response to the pandemic. Testing at the Utah Public Health Laboratory was stopped, and the 24/7 coronavirus hotline went offline.[15]

Salt Lake City schools were closed due to the pandemic.[19] The Salt Lake City School District was distributing food and computers to families, and distribution was disrupted due to the quake.[15]

Airport

Salt Lake City International Airport was shut down and "60 to 70 flights" were diverted.[5] Passengers were evacuated, which was easier because the airport already had fewer people than usual due to the 2019-20 coronavirus pandemic (about 9,000 compared to 24,000 under normal circumstances).[4] A water line was damaged in Concourse D.[20] News photos showed water flowing from a ceiling in one passenger area.[21] The airport reopened at 1:15pm.[5]

References

  1. ^ ANSS: Magna 2020 , ShakeMap: Station List (accessed March 3, 2020).
  2. ^ ANSS, "Magna 2020", Comprehensive Catalog, U.S. Geological Survey, retrieved March 18, 2020
  3. ^ "5.7-Magnitude Earthquake Hits Near Salt Lake City: 'The Last Thing We Need Right Now'". Retrieved March 18, 2020.
  4. ^ a b c d "Earthquake Shakes Utah, Rattling Frayed Coronavirus Nerves". Bloomberg.com. March 18, 2020. Retrieved March 18, 2020.
  5. ^ a b c d e f g h "Utah earthquake: Big aftershock hits, acid plume no longer dangerous, emergency declarations issued". The Salt Lake Tribune. Retrieved March 18, 2020.
  6. ^ a b c d Canham, Matt (March 18, 2020). "Earthquake, a 5.7, hits Utah's Wasatch Front, largest since 1992". The Salt Lake Tribune. Salt Lake City, Utah: The Salt Lake Tribune. Retrieved March 18, 2020.
  7. ^ Hanna, Jason; Toropin, Konstantin (March 18, 2020). "A 5.7 magnitude earthquake shakes Utah, knocking out power to thousands". CNN. Cable News Network. Retrieved March 18, 2020.
  8. ^ a b Stauffer, McKenzie (March 18, 2020). "5.7 magnitude earthquake shakes Salt Lake County, Utah". KUTV. Salt Lake City, Utah: Sinclair Broadcast Group. Retrieved March 18, 2020.
  9. ^ a b Reavy, Pat (March 18, 2020). "5.7 earthquake hits near Magna, shakes entire Wasatch Front". Deseret News. Salt Lake City, Utah: Deseret News. Retrieved March 18, 2020.
  10. ^ Feelright, Will. "Magna earthquake felt throughout northern Utah and southern Idaho". Cache Valley Daily. Retrieved March 18, 2020.
  11. ^ "ShakeMap for M 5.7 - 6km NNE of Magna, Utah 2020-03-18 13:09:31 (UTC)40.751°N 112.078°W11.9 km depth". Earthquakes at United States Geological Survey.
  12. ^ Kjolseth, Francisco. "A magnitude 5.7 earthquake hits Utah. Here is the latest". Salt Lake Tribune. Retrieved March 18, 2020.
  13. ^ "M 5.7 - 6km NNE of Magna, Utah 2020-03-18 13:09:31 (UTC)40.751°N 112.078°W11.9 km depth Aftershock Forecast".
  14. ^ Eldredge, S.N.; Clarke, V. (1996). "The Wasatch Fault" (PDF). Public Information Series 40. Utah Geological Survey.
  15. ^ a b c d "5.7-magnitude earthquake shakes Salt Lake City, Utah, and surrounding areas". NBC News. Retrieved March 18, 2020.
  16. ^ "Earthquake updates: Red Cross offers resources to Utahns impacted by earthquake". KSL.com. Retrieved March 19, 2020.
  17. ^ "Salt Lake earthquake". Talking Utah Radio. Retrieved March 19, 2020.
  18. ^ "KMRI Special Temporary Authority". Federal Communications Commission. Retrieved March 20, 2020.
  19. ^ "5.7-magnitude earthquake strikes Utah knocking out state's coronavirus hotline". www.msn.com. Retrieved March 18, 2020.
  20. ^ CNN, Jason Hanna and Konstantin Toropin. "5.7 magnitude earthquake in Utah knocks out power to thousands and diverts flights". CNN. Retrieved March 19, 2020. {{cite news}}: |last1= has generic name (help)
  21. ^ Salt Lake City airport evacuates, halts operations following magnitude 5.7 earthquake