1935 Helena earthquake

1935 Helena earthquake
1935 Helena earthquake is located in Montana
Helena
Helena
1935 Helena earthquake
UTC time1935-10-19 04:48:02
ISC event904601
USGS-ANSSComCat
Local dateOctober 18, 1935 (1935-10-18)
Local time22:48
Magnitude6.2 Ms[1]
Epicenter46°36′N 112°00′W / 46.6°N 112.0°W / 46.6; -112.0
TypeStrike-slip
Areas affectedMontana, United States
Max. intensityMMI VIII (Severe)
Aftershocks6.0 Ms Oct 31 at 18:37
Casualties4 (2 from the mainshock and 2 from the aftershock of October 31)

The 1935 Helena earthquake occurred at 22:48:02 MDT on October 18 in Montana, with an epicenter near Helena.[2] It had a magnitude of 6.2 on the surface-wave magnitude scale and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. The temblor on that date was the largest of a series of earthquakes that also included a large aftershock on October 31 of magnitude 6.0 and a maximum intensity of VIII.[3] Two people died in the mainshock and two others died as a result of the October 31 aftershock. Property damage was over $4 million.[4]

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  2. ^ Cite error: The named reference USGS was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference NGDC_AS was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference L&C Co was invoked but never defined (see the help page).