1935 Helena earthquake
| UTC time | 1935-10-19 04:48:02 |
|---|---|
| ISC event | 904601 |
| USGS-ANSS | ComCat |
| Local date | October 18, 1935 |
| Local time | 22:48 |
| Magnitude | 6.2 Ms |
| Epicenter | 46°36′N 112°00′W / 46.6°N 112.0°W |
| Type | Strike-slip |
| Areas affected | Montana, United States |
| Max. intensity | MMI VIII (Severe) |
| Aftershocks | 6.0 Ms Oct 31 at 18:37 |
| Casualties | 4 (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. 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. Two people died in the mainshock and two others died as a result of the October 31 aftershock. Property damage was over $4 million.