A minor earthquake rattled southern Maine this evening and was felt throughout New England. Update at 8:40 p.m. ET: Nonplussed by the relatively small quake, some Twitterers have weighed in with a little humor: Californians Declare 4.5 Magnitude Earthquake 'Absolutely Adorable.' @MrWordsWorth Great earthquake of our time. @Ayo_61 Hour one after earthquake: food is low. Water is almost gone. Supplies on the verge if nothing. Survival is not likely. Most remember the rule "stop, drop and roll" when it comes to fires. Federal emergency management officials want to add "drop, cover and hold on" to our memory banks. Those are the instructions given during an earthquake, and people across five states, including Maryland, and the District of Columbia will be practicing them on Thursday. The Federal Emergency Management Agency and Central U.S. Earthquake Consortium are holding "The Great Southeast ShakeOut", a widespread earthquake response drill. Given the August 2011 earthquake that rattled up and down the East Coast, the practice is important, officials said. It will take place at 10:18 a.m. Thursday in Georgia, South Carolina, North Carolina, Virginia, Maryland, and the District of Columbia.The U.S. Geological Survey revised its report of Tuesday's earthquake to magnitude 4.0, down from a preliminary magnitude of 4.6. The epicenter was pinpointed 4 miles west-southwest of Hollis Center, Maine, at a shallow depth of 4.2 miles. Despite the downgrade, the quake was felt as far away as Boston, Massachusetts; Albany, New York, and even Waterbury, Connecticut, according to the USGS. You can report your earthquake experience to the USGS at the above link, as well as adding your comment to the many at the end of this post.First reported as a 4.5 magnitude quake centered near Lake Arrowhead, the USGS revised the quake's magnitude to 4.6 and finally down to 4.0. It shifted the epicenter to close to Hollis Center, southeast of the original location, and revised the quake's depth from a deep 17 miles (27 km) to a relatively shallow 3 miles (4.8 km). Hollis Center is about 20 miles (32 km) west of Portland, Maine's most populous city, and about 100 miles (160 km) north of Boston.