EARTHQUAKE! Important Question…

[jrenaut]

Traffic-free? I wish. I was on my bike when it happened, down at the Navy Yard, waiting at a light. The PA Ave cycle tracks were FULL of clowns, and on 15th St I had to cross the street because the tracks were impassable. Then I had to walk my daughter 15 blocks home from her first day of preschool with the littler daughter on my back because the buses were so full they weren’t even stopping. But we’re okay, so that’s the important part.

[CCrew]

Delivered the daughter to UVA on Saturday. Quake epicenter was 8 miles from her. Needless to say she’s a happy camper

[Greenbelt]

Amazing that a 5.8 100 miles away could cause such a commotion. In California, that would have been a total ho hum. I tried to explain to my co-workers that a new steel and glass building can handle that amount of shaking no sweat. But oh well, they were out in the streets!

Was a great ride home for us, except that the Capitol police blocked all the streets around the Capitol. We scooted around the jams, though. Beautiful weather and fun the ride above the traffic jams.

[PotomacCyclist]

National Cathedral and some Smithsonian buildings were damaged. The Cathedral suffered cracks in the flying buttresses and three pinnacles fell of the main tower. Some of the Smithsonian buildings suffered cracked beams. The Smithsonian Secretary said some of the buildings may also have foundation damage, but they have to check. The Smithsonian Castle might be the most vulnerable, since it’s the oldest of the buildings.

[Brent]

I was actually worried about my bike today. I rode the Reston Century on Sunday, and my bike got soaked. I had it up on the bike stand, ready to do some maintenance when I got home from work. I was afraid it could have fallen off…but alas, everything was good.

[acc]

I was in a restaurant with my 9 year-old son and the building shook like a snow globe. I told him to stand with me against what appeared to be a load carrying beam and watched people run outside into an area with power lines, traffic, and the potential for flying glass. Once I realized my house was just a messy as before the quake and everything seemed to be more or less ok, I drove into Arlington for a ride. Heck, I survived so might as well get on with life. I saw a lot of very unhappy looking people packed in like sardines on the Metro as I drove up I-66. Traffic was almost gridlocked out in Vienna around 5:30. That got me to thinking, if I ever needed to make a run for it, a bike is the only way to get out of town. I’d never make it with my kids in a car. With backpacks and a fairly decent knowledge of where water and supplies are likely to be, we could get as far as P’ville and find shelter for the night. I am glad everyone seems to be ok.

Survive. Breathe. Keep riding.
ann

[SteveTheTech]

@Greenbelt 7468 wrote:

Amazing that a 5.8 100 miles away could cause such a commotion. In California, that would have been a total ho hum. I tried to explain to my co-workers that a new steel and glass building can handle that amount of shaking no sweat. But oh well, they were out in the streets!

I wonder if the plates we sit on are made of rock that transmits shock over a longer distance as opposed to west coast faults. The distance and intensity reported all over the east coast seem pretty interesting. The fact that the majority of the life long east coast residents (myself included) have never felt an earthquake of maybe a magnitude of 3 could also be a slight contributing factor to the reports. Seems like something very instinctual in everyone says “Get up now and move”.

What seems really…well kind of frightening is the lack of preparedness and failure of the cell networks, and fairly quick traffic lockdown in many segments of the area. I know my wife and I don’t have a backup plan if something more significant (>non forecasted weather) or if relocation were needed.
This area is still dangerously unprepared.

Seems like our weather phenomena tend to come in twos.
What’s going on here…

So I guess we might be able to answer the question many of us asked during the week after the blizzard, the same storm with rain would be much easier…seems like now we might find out.

[Brent]

@SteveTheTech 7480 wrote:

I wonder if the plates we sit on are made of rock that transmits shock over a longer distance as opposed to west coast faults.

I grew up in St. Louis, which is not that far from the New Madrid Fault. That fault caused a massive series of earthquakes in 1811-1812 that did all kinds of craziness, like shifted the course of the Mississippi River and stuff. I remember after the 1989 earthquake in California, there was all kinds of earthquake paranoia.

Anyway, back to the point: The rock on the east coast is “cold and old.” The older rock tends to be less seismically active, and the colder rock tends to be harder, transmitting the earthquake vibrations for longer distances. On the west coast, the rock is younger (meaning more seismically active) and softer, dampening the seismic waves (just like soft cork handlebar tape dampens road vibrations ).

This is my understanding of things, but any geologists out there should correct me if I’m wrong.

[Tim Kelley]

@Brent 7486 wrote:

This is my understanding of things, but any geologists out there should correct me if I’m wrong.

Getting even further from the topic of bicycles, I got the below message from my mother, who just happens to be a geologist. (I’ve only seen her ride a bike once, and it was on a dare when I was 12 because I didn’t believe she could.)

“See: http://www.geol.vt.edu/outreach/vtso/cvsz.html

I was trying to find some animations that would show how seismic waves propagate – there are some on youtube for instance.
http://www.youtube.com/watch?v=9J6EHnra7Mo&feature=related

Anyway, there are different types of seismic waves and they travel differently depending on what kind of material they are passing through (e.g., whether it is solid rock or unconsolidated sediment, whether it is liquid or solid, etc.). How deep they occur also affects the way they propagate because rocks at different depths are at different pressure. Some types travel faster and some slower, and they cause material to vibrate differently. The amplitude of the seismic waves decreases the farther you get from the point of origin, but if the earthquake is powerful enough you will be able to feel them at a distance (and a seismograph can detect them even better).

This link shows how long it would take for the VA waves to arrive in other places around the globe.
http://neic.usgs.gov/neis/eq_depot/2011/eq_110823_se082311a/se082311a_t.html

The USGS has a lot of earthquake stuff – you might be interested in this summary of the geological background:
http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/se082311a.html#summary
Kind of fun!”

[Brent]

@Tim Kelley 7492 wrote:

Getting even further from the topic of bicycles…

Earthquakes shake the ground…we ride our bikes on the ground…

[5555624]

… and bridges.

I found it amusing that people were not being let back into office buildings until they could be inspected, but no one seemed to think the bridges needed to be checked.

[Author]

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