USGS: 1906 Ground Motion Simulations

USGS ^ | 3/28/06 | USGS

[NormsRevenge]

Overview

To better understand the distribution of shaking and damage that accompanied the great 1906 earthquake, seismologists have constructed new computer models to recreate the ground motions. The simulations show how ground moved on the two sides of the San Andreas fault and how seismic waves radiated away from the fault to produce the shaking. The earthquake, which began 2 miles offshore from the City of San Francisco, ultimately grew to cause shaking and damage along more than 300 miles of the San Andreas Fault.

The movies and snapshots available here portray the shaking over a 155 mile by 70 mile area covering the San Francisco Bay region. They are offered in .mov format, which can be viewed using a variety of plugins available for most browsers. These movies are typically 4 MB or more in size, and are best downloaded using a high speed internet connection. Snapshots from one movie are also offered as an alternative for those with slower modem connections.

[NormsRevenge]

http://earthquake.usgs.gov/regional/nca/1906/simulations/

Five second snapshots taken from one of the movies available below. Yellow to red colors indicate regions experiencing damaging shaking. Isolated regions of intense shaking, like the one near Santa Rosa 20 miles from the fault, result from a combination of the amount of slip nearby on the fault, the geologic materials that the seismic waves travel through, and the local geologic conditions.

[bd476]

Earthquake Ping List. Please send a Freepmail if you want to be added
or removed from this list.

[Howlin]

Oh, this is neat! Thanks.

[fatima]

Thanks for the ping bd476.

[hole_n_one]

Here is a downloadable program that details the 1994 Northridge quake. Along with a map and running clock, the program shows the main quake and subsequent aftershocks with their associated locations.

It's amazing just how many aftershocks there were withing the first 2 days after the main event.

There are detailed instructions within the program instructing you how to speed up/down and pause the events.

I trust it's simply a matter of downloading and opening the execute file without the need of any special program in order to view it.

I can vouch for the safety and security of the program in that I just uploaded it and it is being hosted on my lame "web site".

[NormsRevenge]

Thanks for pinging .

Saw a news report on this tonight and wanted to post it for the FR crew and those in the area..

[hole_n_one]

PS........

To advance beyond the first and any subsequent screens detailing instructions, you need to hit the enter key.

[NormsRevenge]

Thanks! There were aftershocks all over the place .

It took a bit to download and ya need to hit the return key once the initial screens come up to proceed..

[NormsRevenge]

Got it!

[Global2010]

Thanks for the ping.

I cannot access so I have a ?

Can they show a history prior to the big quakes and have they come to any conclusive data with any studies done thus far.
Two ?'s I guess.

I have a seminar coming up in May or June on the Cascadia and if any new data comes out of that (if I can discern what the heck they are saying) I will let you guys know.

[Dallas59]

Fire destroyed SF much like the flood did NO in...WOW!! I just spilt hot soup in my lap! i'm not kidding. i haven't felt like this in years. My chair is soaked. excueme. wow.

[hole_n_one]

I uploaded the program from a floppy.

With the floppy disk, it's completely animated with running clock and calender. Its starts on 17 Jan 1994 at Midnight, with the main event shwoing at 4:31am and then each subsequent aftershock being displayed.

Out of curiosity, I went and downloaded the file that I uploaded, and the downloaded version simply shows the last screen without any animation.

Is the progarm you downloaded animated and are you able to manipulate the speed of the events?

[NormsRevenge]

I just spilt hot soup in my lap! i'm not kidding.

--

Ouch! fyi - I have notifed FEMA.

They will be onsite shortly to assist you. I told them a levee busted in your back yard. ;-)

[NormsRevenge]

I saw the same thing,. the last screen came up.

The USGS stuff here is not adjustable speed-wise that I can see.

[Dallas59]

It was amazing....I have my $125 dollar chair in the shower...I was typing, little did I know that inch by inch, tap by tap my bowl of Campbell's Vegetable Beef soup was heading for my lap. Then....a spreading warmth engulfed me...It just kept going on...I didn't want it to stop. Wow.



As I was saying, Fire destroyed SF much like the flood in NO. The hurricane so to speak did little damage.

[hole_n_one]

Right click here and "save link as" to the same place as the execute file and it should work as intended.

With both files downloaded, it works great!

[Howlin]

Will there be a test on this "after?"

[hole_n_one]

You need to download 2 files in order for it to work properly.

One is the execute file while the other is the data file.

The 2nd file that needs to be downloaded is at #16.

[Paleo Conservative]

Karl Rove should team up with the USGS to get a repeat of the 1906 earthquake. Forget computer simulations.

[Redcloak]

Isolated regions of intense shaking, like the one near Santa Rosa 20 miles from the fault, result from a combination of the amount of slip nearby on the fault, the geologic materials that the seismic waves travel through, and the local geologic conditions.

If you look at the first few frames, you can see the interference fringes forming as the waves propagate and bounce off of subsurface features. Places like Santa Rosa were on nodes in the fringe pattern. On a node, the waves combine and build on top of one another. (On an anti-node, the crest of one wave falls into the trough of another partially, or totally, cancelling out the two waves.)