On 1 April 1965, at 05:48 U.T., a meteor struck the earth in the Banff-Penticton area of British Columbia, Canada. The meteor was sighted and recorded by seismic and infrasonic equipment. The U. S. Coast and Geodetic Survey analyzed Canadian and United States seismograms from the immediate vicinity. Sufficient acoustic, surface, and body-wave seismic signals were recorded to outline an epicentral area of impact. This assisted the Canadian Government in carrying out an aerial photographic survey and on-site inspection tour. This represents the most geophysical data available on this unique event, and perhaps the best documented within recent historical times.

Studies of earthquake aftershocks as a function of space, time, and rate of energy release (magnitude) afford new evidence of earth structure. The sharp boundary conditions of the epicenter locations suggest block faulting about the Rat Islands as a subsystem of the Aleutian Islands arc structure. Earthquake frequency of occurrence in time and magnitude are given.

Salmon, an underground nuclear explosion in the Tatum salt dome in Southern Mississippi, was seismically recorded throughout North America and at some overseas stations. Data are presented from 143 seismograph stations recording signals from the Salmon event. Travel times at smaller distances generally confirm the high upper mantle velocities indicated by Gnome as recorded in the eastern United States. Travel times for the area east of the Rocky Mountain front may generally be represented by the equation t = Δ/8.3 + 8 seconds (Δ in kilometers); however, additional detail is shown indicating apparent velocities of up to 8.7 km/sec. In the 10° to 20° distance range multiple arrivals are apparent, and beginning near 16° late initial arrivals are observed which correspond to Jeffreys‐Bullen travel time. Amplitudes were generally higher than expected for regional and for teleseismic distances but lower in the 13° to 22° range in the western United States. A revision to procedures for determining magnitudes is shown to be necessary.

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