Map of Indiana Showing Earthquake Epicenters and Structural Features Map and geodatabase

Abstract

The earthquake data presented on this map come from a catalog compiled from the Advanced National Seismic System (ANSS) Comprehensive Earthquake Catalog (ComCat), the Earthquake Catalog (1568 to 2018) for the USGS National Seismic Hazard Model and Nuclear Regulatory Commission, and other supplementary sources. This map documents earthquake epicenters through 2023, based on data published by various sources, including the U.S. Geological Survey, the Indiana Geological and Water Survey, and the U.S. Nuclear Regulatory Commission. The map uses the moment magnitude scale (Mw) to represent earthquake magnitudes, which measures the total energy released during an earthquake. This energy is proportional to the fault slip multiplied by the area of the fault surface that slips. The moment magnitude provides an estimate of earthquake size. Earthquakes below Mw 3.0, which release energy levels typically imperceptible to humans, are not shown. Additionally, non-tectonic events (for example, mine blasts), and duplicate entries have been excluded.

The fault traces shown on the map are derived from structural feature data available on IndianaMap (www.indianamap.org). Most of these faults are buried, meaning they lack significant surface expression. Notable exceptions include the Mt. Carmel Fault and the Kentland Disturbance, which are surface faults.