Earthquake rumblings

We just felt a rumble from the 4.0 (corrected 10/17 per updated info from USGS) magnitude Earthquake just west of Hollis Center, Maine which is about 85 miles SW from us.   The US Geological Survey has a great website www.earthquake.usgs.gov that has real-time earthquake info.  We guessed what it was a couple of minutes before the website content was updated and confirmed our suspicion.  Fortunately our house will be built on ledge which will reduce the potential for impact from such rumblings.