Overview
- The U.S. Geological Survey confirmed a magnitude 2.9 earthquake about 13 miles off Evanston that was recorded in the early afternoon on Wednesday.
- More than 170 residents reported feeling light shaking and short lived effects such as choppy water across North Shore communities and parts of Chicago.
- Northwestern University researchers say the quake was unusually shallow, about 5 kilometers beneath the lake bottom, and they are merging campus instrument data with seismometer records for analysis.
- CBS and Northwestern scientists noted a possible smaller aftershock the following morning that was below the typical USGS catalog threshold.
- Experts say the Great Lakes region has low seismic activity but improved detection makes small quakes easier to spot, so scientists will watch for more small events even though damaging quakes remain unlikely.