June 18, 2002, Caborn, Indiana Earthquake

Epicenter of the 06/18/2002 shock is near the town of Caborn about 20 km West of Evansville, Indiana. Indiana Geological Survey named the event as Caborn, Indiana earthquake.

Broadband, Vertical-component seismic record at PAL (distance=1,226 km) in Rockland County (about 15 miles North of Manhattan). Pn wave from the quake arrives at around 17:39:53.
The strong signals at around 14:07 is teleseismic waves from a strong earthquake that occurred in Chile-Argentina Border Region (mb=6.5, h=52 km, QED/NEIC).

Focal Mechanism by Waveform Moment Tensor Inversion

Source mechanism of the Caborn, Indiana, earthquake determined by using seismic signals recorded at regional distance (from 123 to 581 km). Waveform data are used to determine focal depth and source mechanism parameters using moment tensor inversion method. This is a preliminary results. Source mechanism indicates predominantly strike-slip motion along steeply dipping fault planes striking due Northeast or Northwest (298 degree). Source depth of 18 km fits the observed records best.

Focal Depth

Focal depth has been constrained by comparing solutions for various focal depths and finding the best fit synthetic seismograms that yield smallest fitting errors between observed and synthetic traces.

June 18, 2002 earthquake and the Wabash Valley seismic zone

Location of the June 18, 2002 Caborn, Indiana earthquake. It occurred in the Wabash Valley seismic zone and perhaps along northeast trending compound Caborn fault.

Major Earthquakes in the Eastern United States

Recent Earthquakes in the Eastern U.S. with known source mechanism. Notice that June 18, 2002 earthquake is close to the event on June 10, 1987 (labeled 870610).

Additional links

• IRIS Incorporated Research Institutions for Seismology (new navigator window)
  
• NEIC/USGS National Earthquake Information Center (new navigator window)
  
• PEPP/Indiana/Purdue Princeton Earth Physics Project (new navigator window)
  
• CERI/U. Memphis Center for Earthquake Research and Information, Univ. of Memphis (new navigator window)