An interpretation of the November 7, 1882, Colorado earthquake. 36 pages. Digital PDF download. OF-86-08D
From the Abstract:
On November 7, 1882 an earthquake rocked parts of Colorado, Wyoming, Utah, and Kansas. It was felt over 470,000 km, with a maximum reported Modified Mercalli intensity of VII. An isoseismal map for the main event and the felt area of an aftershock on November 8th, along with historic wave path and focusing considerations, suggest the epicenter was probably in north-central Colorado, perhaps in the northern Front Range or possibly southern Laramie Mountains. The felt area for the aftershock is in our opinion the most significant factor for defining the general epicentral location for the main earthquake. Earthquake magnitude is estimated at 6.2 + 0.3 ML, based on felt area size. Similarities with the 1984 Laramie Mountains earthquake support an interpretation that the 1882 event probably occurred at a fairly great depth, perhaps 20 km or more. The possibility of there having been two earthquakes closely spaced in time at different locations was specifically addressed and no data supporting this theory was found.