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1979. Dark blue ball-point pen signature on a 3 x 5-inch card, no place, March 10, 1979. Hinged to an 11 x 8-inch page containing an image of the scientist and a small bio, housed in protective plastic. Fine condition. World acclaimed Seismologist who devised the scale of earthquake magnitude that has been the standard for measuring earth tremors since 1935, commonly referred to as the "Richter Scale."