LA earthquakes - peak ground acceleration 1

[glass99]

Does anyone know where to find the actual peak ground acceleration in LA from the recent Ridgecrest earthquake(s)? The epicenter was 100 miles from LA so there would be a lot of attenuation, but I'm sure the USGS has the actual ground motion measurements online somewhere.

 

[IRstuff]

There's

https://earthquake.lacity.org/

which also answers the question about any correlation between time of day and earthquakes, as a general rule. That's not to say that some earthquakes might be triggered by tidal motions.

Also

https://www.fdsn.org/networks/detail/CI/

and specifically

http://www.scsn.org/index.php/earthquakes/live-seismogram-feed/index.html

TTFN (ta ta for now)
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[glass99]

thanks IR stuff - these graphs seem to be either qualitative or in some weird units (microvolts?). Do you have to pay to get actual ground accelerations?

 

[GC_Hopi]

Here is the USGS site. [URL unfurl="true"]https://earthquake.usgs.gov/earthquakes/eventpage/ci38443183/shakemap/intensity[/url] I believe someone previously posted where to get the time history data. Its tempting to apply the time history on some current models/designs I did...

 

[glass99]

thanks GC_Hopi. Actually indirectly I got what I think i need which is a plot of peak ground acceleration vs distance to the rupture.

Can you actually get time histories? I don't think you could use them officially bc that would take some soils interpretation, but super cool nonetheless.

 

[GC_Hopi]

Here is a previous post with a few time histories. I believe there is some code language that allows you to use some minimum number of actual time histories within some distance of your site to validate your structure as an alternative to the code numbers for seismic. But obvious time histories are mostly used for academic purposes.

Further, the Soil Structure Interaction (SSI) you refer to is usually NOT considered for light structures in stiff soils. But is used for certain types of structures and SSI is still in its infancy as far as our understanding goes. Wiki has a nice description