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Isoseismal map for the earthquake north-east of Denver - 9 August 1967 - MMI VII. (detail) Kirkham, Robert M., and William P. Rogers. “Bulletin 52 - Colorado Earthquake Information, 1867-1996.” Earthquake. Bulletin. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2000. https://coloradogeologicalsurvey.org/publications/colorado-earthquake-information-1867-1996.

Case Study: Denver – August 9, 1967

1967-08-09 | CGS Admin

Major magnitude 5.3 earthquake shock in Denver  

One of the strongest and most economically damaging earthquakes to affect the Denver area in the 1960s occurred on August 9, 1967 around 6:30 AM, awakening and frightening thousands of people. This magnitude 5.3 earthquake, centered near Commerce City, caused more than eight million dollars (2022 dollars) in damage in Denver and the northern suburbs.

Felt reports and intensity ratings were described by von Hake and Cloud (1984). Intensity VII damage was reported in Northglenn, where plate glass windows broke, many walls, ceilings, foundations, and concrete floors cracked, and several businesses sustained damage due to fallen merchandise. One liquor store had estimated damage at USD $90,000 to $175,000 (2022 dollars).

Intensity VI damage was reported in 28 locations, many of which suffered considerable cracked plaster and mortar, broken windows, damaged foundations and chimneys, and damage to household goods. The earthquake was felt as far as Sterling to the northeast and Pueblo, Colorado to the south, as well as north to Laramie, Wyoming.

Based on the isoseismal map, the estimated felt area was about 20,000 mi2 (50,000 km2). Von Hake and Cloud (1984) proposed a size of 15,000 mi2 (39,000 km2), while Hadsell (1968) indicated it was felt over 45,000 mi2 (117,000 km2). Docekal (1970) reported a felt area of 20,000 mi2 (52,000 km2). A magnitude of Mb 5.3 was reported for this earthquake by von Hake and Cloud (1969). Nuttli and others (1979) calculated an Mb of 4.9 and ms of 4.4. Herrmann and others (1981) suggested a focal depth of 1.9 mi (3 km) for this event. The overall felt area is prominently elongated in directions parallel and perpendicular to the (north-south oriented Front Range) mountain front. The intensity V and VI contours are also oriented in an elongate pattern perpendicular to the mountain front.

Aerial view of the Rocky Mountain Arsenal, south plant, 1970. Photo credit: US Library of Congress.
Aerial view of the Rocky Mountain Arsenal, south plant, 1970. Photo credit: US Library of Congress.

This substantial earthquake, the largest of a long series, is believed to have been triggered by the deep injection of chemically-charged wastewater into a borehole drilled to a depth of 12,045 ft (3671 m) at the Rocky Mountain Arsenal in 1961. It was followed by an earthquake of magnitude 5.2 on November 27, 1967. In total, between 1962 and 1967 the U.S. Geological Survey (USGS) recorded over 1,500 earthquakes in the area. The Arsenal was a large chemical weapons-manufacturing facility run by the U.S. Army in Commerce City. Wastewater injection at the site stopped in 1966 and the entire facility closed in 1992. Much of the area is now a national wildlife refuge.

NOTE: Instructions on accessing pdf copies of the citations listed following may be found at our Earthquake Reference Collection, which contains more than 500 references related to seismicity in Colorado and the region.

Citations, Categories & Tags

Citations

Our Earthquake Reference Collection which includes most of the following references—is available to researchers—see instructions on that page to access the collection.

Bardwell, George E. “Some Statistical Features of the Relationship between Rocky Mountain Arsenal Waste Disposal and Frequency of Earthquakes.” The Mountain Geologist 3, no. 1 (1966): 37–42.
Bott, J.D., and I.G. Wong. “What’s Been Happening at the Rocky Mountain Arsenal? (Abstract Only),” 1996.
Docekal, Jerry. “Earthquakes of the Stable Interior with Emphasis on the Midcontinent (Volumes 1 & 2).” PhD, University of Nebraska, 1970.
Evans, David M. “The Denver Area Earthquakes and the Rocky Mountain Arsenal Disposal Well.” The Mountain Geologist 3, no. 1 (1966): 23–36. https://doi.org/10.1130/Eng-Case-8.25.
———. “The Denver Area Earthquakes and the Rocky Mountain Arsenal Disposal Well.” In Engineering Geology Case Histories Number 8- Engineering Seismology: The Works of Man, edited by WM. Mansfield Adams, 25–32. GSA Engineering Geology Case Histories. Geological Society of America, 1970.
Hadsell, F. A. “History of Earthquake Activity in Colorado.” Colorado School of Mines Quarterly 63, no. 1 (1968): 57–72.
Hake, Carl A. von, and William K. Cloud. “United States Earthquakes, 1967.” Open-File Report. Open-File Report. Washington, D.C.: U.S. Geological Survey, 1984. https://pubs.er.usgs.gov/publication/ofr84967.
Healy, J.H., and D.B. Hoover. “Microearthquakes near the Rocky Mountain Arsenal Well, Denver, Colorado.” Geological Society of America Special Paper 115 (1968): 422.
Heerschap, Lauren, and Matthew L. Morgan. “HA-84 HAZUS 2006: Rocky Mountain Arsenal Earthquake Event Report.” Earthquake Simulation. Golden, CO: Colorado Geological Survey, 2006. https://coloradogeologicalsurvey.org/publications/hazus-report-rocky-mountain-arsenal.
Herrmann, Robert B., Sam-Kuen Park, and Chien-Ying Wang. “The Denver Earthquakes of 1967-1968.” Bulletin of the Seismological Society of America 71, no. 3 (June 1, 1981): 731–45.
Hollister, John C., and Robert J. Weimer, eds. Geophysical and Geological Studies of the Relationships Between the Denver Earthquakes and the Rocky Mountain Arsenal Well Part A. Vol. 63. 1. Golden, CO: Colorado School of Mines, 1968.
Hoover, Donald B., and J.A. Dietrich. “Seismic Activity during the 1968 Test Pumping at the Rocky Mountain Arsenal Disposal Well.” Report. Circular. Washington, D.C.: U.S. Geological Survey, 1969. USGS Publications Warehouse. http://pubs.er.usgs.gov/publication/cir613.
Kirkham, Robert M., and William P. Rogers. “Bulletin 46 - Colorado Earthquake Data and Interpretations 1867-1985.” Earthquake. Bulletin. Denver, CO: Colorado Geological Survey, Department of Natural Resources, 1985. https://coloradogeologicalsurvey.org/publications/colorado-earthquake-data-interpretation-1867-1985.
———. “Bulletin 52 - Colorado Earthquake Information, 1867-1996.” Earthquake. Bulletin. Denver, CO: Colorado Geological Survey, Division of Minerals and Geology, Department of Natural Resources, 2000. https://coloradogeologicalsurvey.org/publications/colorado-earthquake-information-1867-1996.
Morgan, Matthew L., and F. Scot Fitzgerald. “HA-84 HAZUS 2013: Rocky Mountain Arsenal Earthquake Event Report.” Earthquake Simulation. Golden, CO: Colorado Geological Survey, 2013. https://coloradogeologicalsurvey.org/publications/hazus-report-rocky-mountain-arsenal.
Nuttli, Otto W., G. A. Bollinger, and Donald W. Griffiths. “On the Relation between Modified Mercalli Intensity and Body-Wave Magnitude.” Bulletin of the Seismological Society of America 69, no. 3 (June 1, 1979): 893–909. https://doi.org/10.1785/BSSA0690030893.
Omaha District Corps of Engineers. “Injection Well Earthquake Relationship- Rocky Mountain Arsenal, Denver, Colorado.” Report of Investigations. Omaha, NE: Omaha District Corps of Engineers, October 1, 1966.
Scopel, Louis J. “Pressure Injection Disposal Well, Rocky Mountain Arsenal, Denver, Colorado.” The Mountain Geologist 1, no. 1 (1964): 35–42.
Van Poollen, H.K. “Pumping Tests: Rocky Mountain Arsenal Disposal Well September-October 1968.” Littleton, CO: U.S. Army Engineer District, January 1969.
Whitney, Justin. “Resistance in the Midst of the Anthropocene: The Rise and Fall of Artificial Earthquakes at the Rocky Mountain Arsenal, 1962–1966.” Environment & Society Portal, October 4, 2019. https://www.environmentandsociety.org/arcadia/resistance-midst-anthropocene-rise-and-fall-artificial-earthquakes-rocky-mountain-arsenal.

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case study, Denver Basin, earthquake, Front Range, hazards, RockTalk, seismology