The maximum S-amplitude, given in mm scale of a recorded earthquake by a standard seismometer at 100 km away from the epicenter, is converted to magnitude (M) by the following relation. About 900-1,000 times more energy.
MG is a British automotive marque registered by the now defunct MG Car Company Limited, a British sports car manufacturer begun in the 1920s as a sales promotion sideline within W R Morris's Oxford city retail sales and service business by the business's manager, Cecil Kimber.
Background to the MGC. The MGC was firmly based on the MGB, and was intended as a replacement for the Austin-Healey 3000 which, by the time the MGC was announced in 1967, had had its day. It was powered by an in-line, six-cylinder, pushrod, OHV engine of 2912cc capacity that was capable of developing 150bhp.