United States earthquakes, 1952

Abstract

An asterisk (*) indicates instrumental origin time of the earthquake when coordinates of the epicenter are given. Otherwise, Instrumental times shown with asterisks are those of first motions. When more than one degree of intensity Is reported from a town, the town is listed under the highest intensity reported. More details will be found in the quarterly Abstracts of Earthquake Reports for the Pacific Coast and the Western Mountain Jtegion, MSA series, issued on mailing list CGS-S by the United States Coast and Geodetic Survey, Washington 25, D. C. EARTHQUAKE ACTIVITY IN THE VARIOUS STATES NOTE. The intensities of the earthquakes for which no ratings are given range from I to IV.

Intensity distribution and isoseismal maps for the Nisqually, Washington, earthquake of 28 February 2001

“…Most intensities that are plotted for 1949 in figure 10 were assigned by Stover and Coffman (1993) for the preparation of their intensity map of the 1949 earthquake. These intensities reflect recent USGS conventions for the assigning of MMI from macroseismic data, and they are slightly but systematically lower than the intensities assigned by Murphy and Ulrich (1951) on the basis of the same macroseismic data. The intensities plotted in figure 10 also includes 39 interpretations of the present authors, again applying recent USGS conventions to the macroseismic data reported by Murphy and Ulrich (1951).…”

“…These intensities reflect recent USGS conventions for the assigning of MMI from macroseismic data, and they are slightly but systematically lower than the intensities assigned by Murphy and Ulrich (1951) on the basis of the same macroseismic data. The intensities plotted in figure 10 also includes 39 interpretations of the present authors, again applying recent USGS conventions to the macroseismic data reported by Murphy and Ulrich (1951). The reinterpretations that we made were for observations to which Murphy and Ulrich (1951) assigned MMI 8, and to which we do not know if Stover and Coffman (1993) (1967).…”

“…We think that these differences result in part from shaking in the epicentral region having been stronger in 1949 than in 2001, due to differences in some source property such as the source-time function or the direction of rupture propagation. For most of the towns assigned MMI 8 in 1949, the effects reported on unreinforced masonry chimneys and buildings (Murphy and Ulrich, 1951) were substantially more dramatic than we observed or were reported in the same types of structures in the same towns in 2001.…”

Seismicity of the United States, 1568-1989 (revised)

“…It also was reported felt at Seligman, Ariz. Many aftershocks occurred on Dec. 25 1902. July 28 (July 27).…”

“…This earthquake series consisted of more than 200 foreshocks and aftershocks. The strongest aftershock occurred on Oct. 20 were killed when the north end of the island slumped into the sea, and two people were missing and presumed dead in Lituya Bay from a wave generated by the collapse of 300 million m3 of rock into Gilbert Bay. At Yakutat, bridges, docks, and oil lines were damaged, a water tower fell, and a few cabins were destroyed.…”