Delaware Quake

[roadman65]

An earthquake at 5.1 near Little Creek, DE.
http://www.businessinsider.com/delaware-struck-by-44-magnitude-earthquake-2017-11

[jp the roadgeek]

Keep hearing anywhere between 4.1 and 5.1.  Didn't feel it here in CT (about 250 mi from the epicenter), but a few in neighboring towns said they had a couple of tables shake.

[hotdogPi]

Maybe it was a slightly-misplaced cheesequake. 

[roadman65]

Its like Tom Petty's death.  He is confirmed dead and then moments later he is not dead.   The media, of course will exaggerate things.  We will know tomorrow what the actual recording is.

[Roadgeekteen]

5.1 is medium size right? I would be VERY surprised to feel that! I bet they were to, not many earthquakes on the east coast.

[jeffandnicole]

I was leaving my building in Trenton NJ at the time and didn't feel anything. I met up with co-workers after work, and other than someone saying they we're stopped in their car and felt it shake a little, no one else seemed to have noticed it.

[bing101]

Dang its amazing that a 4.1 quake on the East Coast can be felt in multiple states. But if its on the ring of fire like the West Coast like Cascadia fault, San Andreas and the Alaska faults then a 4.1 quake would only be felt in one section of the state.

[LM117]

I didn't feel anything, not that I'm complaining. The 2011 quake was enough for me.

[PHLBOS]

The final news reports are now saying that it was a 4.1; which equaled that last quake in Delaware from 1871.

The August 23, 2011 quake in Virginia was a 5.8.

I was still at work in Philadelphia when yesterday's quake hit.  I didn't feel or notice anything.  In contrast, when the 2011 quake hit; I felt the (same) building move twice and an evacuation was ordered (we weren't allowed back in until a half-hour later).

[briantroutman]

At the time of the quake, I was in slow moving traffic at the southern end of I-97 approaching US 50-301–which is roughly 63 miles WbS of the epicenter. I didn't feel a thing, although I doubt I would in a car. I didn't know about it until my wife (who was at home) texted me. Our home is roughly 50 miles from the epicenter, almost due north. My wife says she didn't feel the earthquake, although several people in our town reported feeling tremors.

[Bruce]

Note that earthquakes are measured with a logarithmic scale, so the difference between a 5.1 and 5.8 is massive.

Readings are often upgraded and downgraded by the USGS as they get new data. The media will of course republish whatever USGS says, so they're not really at fault.

[freebrickproductions]

Dang its amazing that a 4.1 quake on the East Coast can be felt in multiple states. But if its on the ring of fire like the West Coast like Cascadia fault, San Andreas and the Alaska faults then a 4.1 quake would only be felt in one section of the state.

Well, the states on the East Coast are a lot smaller than the states on the West Coast, in terms of geographic size.

Also, depending on how far below the surface the quake was, it might not have had much of an effect on the surface itself.

[roadman65]

The topography and also the amount of rock below the surface may account as well.

[epzik8]

I'm in Harford County, Maryland and one of my buddies claims today to have felt it. None of the rest of us were aware of it until they brought it up.

[inkyatari]

The topography and also the amount of rock below the surface may account as well.

The famous New Madrid quake in Missouri was felt all the way to Boston, and it's all to do with the geology and geography.  The west coast is more on and closer to sold rock, which acts as a damper, whereas the midwest is all on sediment.  Another quake like that of 1811 / 1812 would cause substantial damage up to Chicago - about 300 miles.

I was reading about the New Madrid area recently, and it seems that a growing consensus is that the New Madrid fault is having a reduction in seismic activity, but the Wabash seismic zone in Illinois and Indiana is the one we should be watching instead.

[kkt]

4.1 is small.  You could feel it, if you were close by and conditions were right, but there would rarely be much damage.

[adventurernumber1]

This news comes as a huge surprise to me, especially since Delaware is on the East Coast of the United States. There have been very small earthquakes from time to time here in Dalton, Georgia, but at least in my lifetime, none have done much more than make things in the house shake a tad with a very faint rumbling noise.

[triplemultiplex]

The famous New Madrid quake in Missouri was felt all the way to Boston, and it's all to do with the geology and geography.  The west coast is more on and closer to sold rock, which acts as a damper, whereas the midwest is all on sediment.  Another quake like that of 1811 / 1812 would cause substantial damage up to Chicago - about 300 miles.

It's actually the other way around.  Western earthquakes aren't felt as far afield compared to the Eastern US because the bedrock out west has many more younger faults.  They make the bedrock less monolithic and make it more difficult for energy to transfer through the rock.
Faulting in the eastern US is far less numerous and what faults are there are way older so the bedrock is better able to transmit the energy of a quake longer distances.

Its like those mattress commercials where they drop the bowling ball on 'regular' mattress and then do it to one of those memory cell ones and you see how much the first one shakes and spills the glass of wine inexplicably resting on the bed.

[inkyatari]

The famous New Madrid quake in Missouri was felt all the way to Boston, and it's all to do with the geology and geography.  The west coast is more on and closer to sold rock, which acts as a damper, whereas the midwest is all on sediment.  Another quake like that of 1811 / 1812 would cause substantial damage up to Chicago - about 300 miles.

It's actually the other way around.  Western earthquakes aren't felt as far afield compared to the Eastern US because the bedrock out west has many more younger faults.  They make the bedrock less monolithic and make it more difficult for energy to transfer through the rock.
Faulting in the eastern US is far less numerous and what faults are there are way older so the bedrock is better able to transmit the energy of a quake longer distances.

Its like those mattress commercials where they drop the bowling ball on 'regular' mattress and then do it to one of those memory cell ones and you see how much the first one shakes and spills the glass of wine inexplicably resting on the bed.

Ahhh.  I was wondering if I was missing something.  Certainly the sediment the midwest is famous for exasperates the situation.