All earthquakesMontana

Montana earthquakes in 1984

17 earthquakes of magnitude 2.5 or more were located in Montana in 1984. The largest: M4.0 8 km SSW of Toston, Montana, Dec 31, 1983.

From the USGS catalog. Times are local to each quake.

19831985

Map

Where every quake of 1984 was located in Montana. Select one for its page.

Open the live map with earthquakes

Every quake of 1984

Magnitude 2.5 and up, newest first.

Month by month

Counted by UTC date, which is how the catalog files them.

MonthQuakesLargestWhere
January 198454.08 km SSW of Toston, Montana
February 198433.81 km WNW of Toston, Montana
March 198423.538 km SSE of Virginia City, Montana
April 198413.010 km SE of Pony, Montana
May 198413.412 km ESE of Swan Lake, Montana
June 198413.124 km W of Hebgen Lake Estates, Montana
July 19840
August 19840
September 198423.631 km NW of Lima, Montana
October 198413.229 km SSE of Mammoth, Wyoming
November 19840
December 198413.534 km SSE of Virginia City, Montana

What this means

The catalog is only as complete as the instruments of the time. Worldwide coverage of magnitude 5 and up dates from the 1960s, and of 4.5 from the 1990s; earlier years hold the large quakes and the ones near a station, so a low count in an early year means fewer instruments, not a quiet earth.

By year

Every year the USGS catalog covers.

Nearby

Montana nowWorldwide in 1984

Sources

Earthquakes, magnitudes, depths, shaking estimates and felt reports from the U.S. Geological Survey Earthquake Hazards Program, read from its live feeds and its catalog back to 1900. Tsunami messages from NOAA’s tsunami warning centers.