Magnitude 5.6 - WESTERN MONTANA - usazad
2005 July 26 04:08:35 UTC
A moderate earthquake occurred at 04:08:35 (UTC) on Tuesday, July 26, 2005.
The magnitude 5.6 event has been located in WESTERN MONTANA.
(This event has been reviewed by a seismologist.)
Earthquake Summary
Felt Reports
Items knocked off shelves at Dillon and Bozeman. Felt (VI) at Dillon and Twin Bridges; (IV) at Bozeman, Butte, Helena, Missoula and West Yellowstone; (III) at Billings, Great Falls, Kalispell and Livingston. Felt (IV) at Island Park and Salmon; (III) at Coeur d'Alene, McCall, Moscow, Rexburg and Sandpoint, Idaho. Also felt (III) at Pullman and Spokane, Washington and in Yellowstone National Park, Wyoming. The quake was felt as far away as Seattle, Washington and Calgary, Alberta.
Tectonic Summary
Montana is one of the most seismically active States in the U.S.
Since 1925, the State has experienced five shocks that reached
intensity VIII or greater
(Modified Mercalli Scale).
During the same interval, hundreds of less severe tremors were felt
within the State. Montana's earthquake activity is concentrated
mostly in the mountainous western third of the State which lies
within a seismic zone that includes western Montana, southeastern
Idaho, western Wyoming, and central Utah
(see Earthquake History of Montana).
There are a variety of fault types represented in this seismic zone.
Some faults clearly show evidence of being the source of many
large-magnitude earthquakes in the past, and some faults do not.
East-central Idaho and western Montana is characterized by long linear
mountain ranges with intervening valleys. Geologically young faults
bound most or all of these mountain blocks. Many of which are capable
of producing large-magnitude earthquakes similar to the largest
earthquakes that have occurred historically in the seismic zone
(about magnitude 7.5). Seismologists have not yet determined the
causative fault of the recent earthquake.
Earthquake Information for MONTANA
Earthquake Details
Magnitude |
5.6 |
Date-Time |
Tuesday, July 26, 2005 at 04:08:35 (UTC) = Coordinated Universal Time
Monday, July 25, 2005 at 10:08:35 PM = local time at epicenter
Time of Earthquake in other Time Zones
|
Location |
45.411°N, 112.596°W |
Depth |
5 km (3.1 miles) set by location program |
Region |
WESTERN MONTANA |
Distances |
22 km (14 miles) N (8°) from Dillon, MT
25 km (16 miles) SW (234°) from Twin Bridges, MT
32 km (20 miles) W (261°) from Sheridan, MT
351 km (218 miles) NE (54°) from Boise, ID
521 km (324 miles) N (354°) from Salt Lake City, UT
|
Location Uncertainty |
horizontal +/- 2.8 km (1.7 miles); depth fixed by location program |
Parameters |
Nst=128, Nph=128, Dmin=67.8 km, Rmss=0.73 sec, Gp= 40°,
M-type=teleseismic moment magnitude (Mw), Version=6
|
Source |
USGS NEIC (WDCS-D)
|
Event ID |
usazad |
Earthquake Maps
Earthquake Location
Scientific & Technical Info
Additional Information, News Reports
Montana is one of the most seismically active States in the U.S.
Since 1925, the State has experienced five shocks that reached
intensity VIII or greater
(Modified Mercalli Scale).
During the same interval, hundreds of less severe tremors were felt
within the State. Montana's earthquake activity is concentrated
mostly in the mountainous western third of the State which lies
within a seismic zone that includes western Montana, southeastern
Idaho, western Wyoming, and central Utah
(see Earthquake History of Montana).
There are a variety of fault types represented in this seismic zone.
Some faults clearly show evidence of being the source of many
large-magnitude earthquakes in the past, and some faults do not.
East-central Idaho and western Montana is characterized by long linear
mountain ranges with intervening valleys. Geologically young faults
bound most or all of these mountain blocks. Many of which are capable
of producing large-magnitude earthquakes similar to the largest
earthquakes that have occurred historically in the seismic zone
(about magnitude 7.5). Seismologists have not yet determined the
causative fault of the recent earthquake.
- News Release
- Earthquake Summary Poster
- ShakeMap shaking intensity maps (Global server)
- Preliminary Earthquake Report
- U.S. Geological Survey, National Earthquake Information Center
World Data Center for Seismology, Denver