i was in a 12 story building, 7th floor in Baltimore. when the virginia 5.8 or 5.9 hit.
the sensation was bump rattle rattle rattle. the bump was the sensation of the chair dropping 4 inches, returning.
not sharp, a little like an elevator brakeing. duration a few seconds, less than 12.
the signature of an undergound nuke is a big pulse followed by rapidly declining reverberations.

a regular earthwuake starts small, builds to a peak in the middle, tapers off. and lasts even minutes.

my experience seems compatible with the nuke signature
on the other hand, the depth seems unlikely to have a deep underground military base, i.e., USGS reports 6 kilometers. think it is too hot to hang out there.

revise my last comment, re virginia quake felt on 7th floor in baltimore.

i interviewed two co workers who were on the ground in baltimore, they said that quake was about 30 seconds, and that it began with with a fore shock... causing visible fluids to slosh, then visible waves in an asphalt parking lot, then back to sloshing. i saw the duration of the quake...from the 7th floor as less than 12 seconds.

i think that i did not feel the fore shock rumblings because the 7 stories were damping them...

SO i my support for an underground nuke is withdrawn. back to the conventional quake view.

the only real bit of information here is that a building can dampen the impact of minor earthquake shock waves.

Originally posted by darkstar57
revise my last comment, re virginia quake felt on 7th floor in baltimore.

i interviewed two co workers who were on the ground in baltimore, they said that quake was about 30 seconds, and that it began with with a fore shock... causing visible fluids to slosh, then visible waves in an asphalt parking lot, then back to sloshing. i saw the duration of the quake...from the 7th floor as less than 12 seconds.

i think that i did not feel the fore shock rumblings because the 7 stories were damping them...

SO i my support for an underground nuke is withdrawn. back to the conventional quake view.

the only real bit of information here is that a building can dampen the impact of minor earthquake shock waves.

well, here is my experience. I was in a 7 story hospital. We most certainly felt it. It last at least 15 secs seemed longer......fear does that. The whole building shook and vibrated. From discussion of employees and patients :
The higher up you were the more you felt it. EX: Basement.....underground.....just a vibration. 7th floor......window blinds swayed back and forth quite noticeably and things on tables vibrated off to the floor. The building was heard cracking and making noises......many reports of this. Louder as one went up(or more noticeable), per witness' accounts. so I don't get how one could say the "building" damped it? Our structure is in bed rock.......unless the type of soil the building in Baltimore is in is more "sand" ; which is very possible. Just saying......this is odd. Not questioning your story darkstar57, just relating to mine in WV.......more inland. Hummmm. Since I have felt another after shock on friday am.............around 0500 or so.........so I tend to think it is EQ's. My question is why? The mountains of WV and VA are very old and there were volcanoes there millions(if you believe the story) of years ago. Hence, Hot springs, Greenbrier, other springs in area......second to volcanic activity a long long time ago. However....Hot Springs still have HOT water there, I have been there...it is quite nice. Could some of the old volcanoes be reactiving....second to earth quakes and old fault lines....crust movement. But what is causing it....?