It had a magnitude of M = 7.7 and a maximum felt intensity of VIII ( Severe ) on the mercalli intensity scale .
The 1935 Sumatra earthquake occurred at 09 : 35 local time on 28 December .
1935 Sumatra earthquake had a magnitude of M = 7.7 and a maximum felt intensity of VIII ( Severe ) on the mercalli intensity scale .
The 1935 Sumatra earthquake occurred at 09 : 35 local time on 28 December .