Michigan Earthquake on October 23, 2001
 
Web page by Dr. Larry Ruff
and MichSeis, the Michigan Seismic Network

Origin Time: 01:33:18.8 (UTC)
Location: 42.34° N, 84.76° W    North of Albion Michigan
Depth: 5 km (fixed)
Magnitude: mbLg = 2.85 (based on 4 MichSeis/OhioSeis stations)
Magnitude: mN    = 2.9  (Canada Nat. Net.)

Note: This hypocenter is based on arrival times from MichSeis/OhioSeis and Canadian stations. There are also seismograms from the USNSN and Indiana/Purdue/PEPP stations. Those seismograms will be used in a future revision to this hypocenter.

Seismograms

• S & Lg waves recorded at MichSeis station AAMC, Close to the epicenter, distance is 82 km. This Lg wave was used for magnitude estimate
   
• P, S, & Lg waves recorded at OhioSeis station BGSO. This Lg wave was used for magnitude estimate
   
• P, S, & Lg waves recorded at OhioSeis station BHSO.
   
• Filtered seismogram recorded at OhioSeis station ACSO.

Felt Reports

This event was widely felt across the northeastern portion of Calhoun County and adjacent portions of Eaton and Jackson Counties, MI. The Calhoun County 911 Dispatch Office has been very helpful in providing felt reports, and MichSeis is conducting a detailed intensity survey.

This earthquake occurred north of Albion, MI. Local origin time 9:33 pm Monday evening, Oct. 22. The map below shows the preliminary estimate of the extent of felt reports.