111˚ Additional information on earthquakes, earthquake preparedness, 110˚ 104˚ Introduction 109˚ 108˚ 107˚ 106˚ 105˚ 45˚ 45˚ and earthquake response can be obtained from: Yellowstone Earthquakes are common in Wyoming. National WYOMING STATE Park Historically, earthquakes have occurred in Sheridan Wyoming State Geological Survey Crook GEOLOGICAL SURVEY every county in Wyoming over the past 120 P.O. Box 3008 Park Bighorn �� ���� years, with some causing significant damage. Laramie, WY 82071-3008 �� �� Lance Cook, State Geologist �� � Campbell Phone: (307) 766-2286 � Figure 1 shows the generalized distribution of Johnson 44˚ 44˚ historical earthquakes in Wyoming. Washakie Fax: (307) 766-2605 � � � Teton Weston � ���� � Email:
[email protected] � �� The first recorded earthquake in the ������ �� Hot Springs
[email protected] state occurred in the area now known as Agency Web: http://wsgsweb.uwyo.edu EARTHQUAKES IN Yellowstone National Park on July 20, 1871. Earthquake Web: http://www.wrds.uwyo.edu During the early geologic investigations of WYOMING Yellowstone, Ferdinand V. Hayden of the U.S. Fremont Natrona Niobrara 43˚ Converse 43˚ Wyoming Emergency Management Agency Geological Survey reported that “on the night 5500 Bishop Blvd. of the 20th of July, we experienced several se- Sublette Cheyenne, WY 82009-3320 vere shocks of an earthquake, and these were Phone: (307) 777-4900 felt by two other parties, fifteen or twenty-five Fax: (307) 635-6017 miles distant, on different sides of the lake.” Email:
[email protected] Platte Goshen Yellowstone National Park is now known as 42˚ 42˚ Agency Web: http://132.133.10.9 one of the more seismically active areas in Lincoln FEMA Web: http://www.fema.gov the United States.