Ohio-Penn EQ of Sept 25, 1998: Aftershock Information

Reports of aftershocks?

• From an earthquake of this size, we might expect to see an aftershock with a magnitude somewhere in the range of 2 to 3. The standard NEIC listing usually does not locate events this small in the midwest.
• There is a possiblity that an aftershock occurred within a few hours after the mainshock -- still checking to confirm that.
• As of Tuesday, Sept. 29, there are no aftershocks reported on the NEIC listings
• Apparently, three teams of seismologists (from the USGS, Lamont Observatory, and University of Memphis) have traveled to the epicentral area to set-up temporary stations to record aftershocks
• At this time, Tues afternoon, Sept. 29, Brian Zimmerman (Edinboro University, PA) kindly sent me e-mail that confirmed that the USGS team is in the field, but NO aftershocks were located as of last night (Mon. Sept. 28).
• At this time, Wed morning, Sept. 30, an update from Brian Zimmerman (Edinboro University, PA) indicates that NO aftershocks have been located.
• As of Fri, Oct 2, still NO confirmed aftershocks.
• As of Mon, Oct 5, still NO confirmed aftershocks. This story is now one of the more unusual aspects of this event. Could the real epicenter be far-away from where the aftershock-team is looking? I don't think so, see first look at epicenter relocation. Click on the USGS site below to get their updates.
• As of Wed, Oct 7, Memphis CERI reports in the web page listed below that:
  still NO confirmed aftershocks.
• Finally, a confirmed aftershock! On Oct 9, The Memphis CERI/USGS/Lamont team recorded an aftershock. The location from the team is close to the NEIC eipcenter, and the magnitude estimate is about 2. The team has a web page for the aftershock information, or click on their EQ link below.
  
• As of Oct. 28, no other aftershocks have been reported by the aftershock team. Their web site now posts a plot of aftershock epicenter.

USGS-Memphis CERI-Lamont Team Aftershock Updates