Difference between revisions of "CyberShake Study 15.12"

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! PAS, previous site amplification (run 4266, blue) vs new deterministic site amplification (run 4275, black)
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! PAS, previous site amp (run 4266: LF_vref=865, vs30=, blue) vs new deterministic site amplification (run 4275, black)
 
| [[File:PAS_4266_v_4275_10s_SA.png|thumb|200px]]
 
| [[File:PAS_4266_v_4275_10s_SA.png|thumb|200px]]
 
| [[File:PAS_4266_v_4275_5s_SA.png|thumb|200px]]
 
| [[File:PAS_4266_v_4275_5s_SA.png|thumb|200px]]

Revision as of 16:38, 30 October 2015

CyberShake Study 15.10 takes the deterministic results from CyberShake Study 15.4 and adds broadband components.


Initial tests

We performed initial tests by using the Graves code from the current version of the BBP to synthesize stochastic seismograms, along with applying site amplification from CB2014. We used the Vs30 value taken from the same velocity model as the deterministic seismograms (CVM-S 4.26). We also applied site amplification from CB2014 to the deterministic seismograms. Then the deterministic seismograms were low-pass filtered at 1.0 Hz, and the stochastic seismograms were high-pass filtered at 1.0 Hz, and the results were combined. From this broadband seismogram we calculated PSA and RotD values.

Run 10 sec SA 5 sec SA 3 sec SA 2 sec SA 1 sec SA 0.5 sec SA 0.2 sec SA 0.1 sec SA
PAS, broadband (run 4266)
PAS 4266 10s SA.png
PAS 4266 5s SA.png
PAS 4266 3s SA.png
PAS 4266 2s SA.png
PAS 4266 1s SA.png
PAS 4266 0.5s SA.png
PAS 4266 0.2s SA.png
PAS 4266 0.1s SA.png
PAS, broadband (run 4266, blue) vs deterministic (run 3878, black)
PAS 4266 v 3878 10s SA.png
PAS 4266 v 3878 5s SA.png
PAS 4266 v 3878 3s SA.png
PAS 4266 v 3878 2s SA.png
PAS 4266 v 3878 1s SA.png
LADT, broadband (run 4271)
LADT 4271 10s SA.png
LADT 4271 5s SA.png
LADT 4271 3s SA.png
LADT 4271 2s SA.png
LADT 4271 1s SA.png
LADT 4271 0.5s SA.png
LADT 4271 0.2s SA.png
LADT 4271 0.1s SA.png
LADT, broadband (run 4271, blue) vs deterministic (run 3870, black)
LADT 4271 v 3870 10s SA.png
LADT 4271 v 3870 5s SA.png
LADT 4271 v 3870 3s SA.png
LADT 4271 v 3870 2s SA.png
LADT 4271 v 3870 1s SA.png

Sample Seismogram

Below is a seismogram for PAS, source 273, rupture 69, rupture variation 50, comparing the 1 Hz seismogram (blue) to the 10 Hz seismogram (green). Mostly, the 10 Hz seismogram looks sharper.

PAS s273 r69 rv50 3878v4266.png

Deterministic Site Amplification

We ran PAS and LADT with and without deterministic site amplification (using CB 2014, and Vs30 values from CVM-S4.26). Here are the results:

Run 10 sec SA 5 sec SA 3 sec SA 2 sec SA 1 sec SA 0.5 sec SA 0.2 sec SA 0.1 sec SA
PAS, site amplification (run 4266, blue) vs no deterministic site amplification (run 4270, black)
PAS 4266 v 4270 10s SA.png
PAS 4266 v 4270 5s SA.png
PAS 4266 v 4270 3s SA.png
PAS 4266 v 4270 2s SA.png
PAS 4266 v 4270 1s SA.png
PAS 4266 v 4270 0.5s SA.png
PAS 4266 v 4270 0.2s SA.png
PAS 4266 v 4270 0.1s SA.png
LADT, site amplification (run 4271, blue) vs no deterministic site amplification (run 4272, black)
LADT 4271 v 4272 10s SA.png
LADT 4271 v 4272 5s SA.png
LADT 4271 v 4272 3s SA.png
LADT 4271 v 4272 2s SA.png
LADT 4271 v 4272 1s SA.png
LADT 4271 v 4272 0.5s SA.png
LADT 4271 v 4272 0.2s SA.png
LADT 4271 v 4272 0.1s SA.png

Modified Vs values

For the stochastic, we continued to use vref=865, and Vs30 calculated by Vs30 = 30 / Sum (1/(Vs sampled from [0.5,29.5] in 1 meter increments)).

For the deterministic, we switched to use vref = Vs @ Z=0 * Vs30 / Vs50 (50 is half the grid spacing of 100m).

Here's a comparison for PAS and LADT.


Run 10 sec SA 5 sec SA 3 sec SA 2 sec SA 1 sec SA 0.5 sec SA 0.2 sec SA 0.1 sec SA
PAS, previous site amp (run 4266: LF_vref=865, vs30=, blue) vs new deterministic site amplification (run 4275, black)
PAS 4266 v 4275 10s SA.png
PAS 4266 v 4275 5s SA.png
PAS 4266 v 4275 3s SA.png
PAS 4266 v 4275 2s SA.png
PAS 4266 v 4275 1s SA.png
PAS 4266 v 4275 0.5s SA.png
PAS 4266 v 4275 0.2s SA.png
PAS 4266 v 4275 0.1s SA.png
LADT, previous site amplification (run 4271, blue) vs new deterministic site amplification (run 4276, black)
LADT 4271 v 4276 10s SA.png
LADT 4271 v 4276 5s SA.png
LADT 4271 v 4276 3s SA.png
LADT 4271 v 4276 2s SA.png
LADT 4271 v 4276 1s SA.png
LADT 4271 v 4276 0.5s SA.png
LADT 4271 v 4276 0.2s SA.png
LADT 4271 v 4276 0.1s SA.png

srf2stoch_lite

To reduce the memory requirements of srf2stoch, Rob Graves created a new version, srf2stoch_lite, with much smaller memory requirements. The differences in hazard curves can be seen here, for PAS. Since srf2stoch is only used in the high frequency, we are only looking at high frequency curves. Blue is with srf2stoch, black is with srf2stoch_lite.

2 sec 1 sec 0.5 sec 0.2 sec 0.1 sec
Curve
PAS 4266 v 4274 2s SA.png
PAS 4266 v 4274 1s SA.png
PAS 4266 v 4274 0.5s SA.png
PAS 4266 v 4274 0.2s SA.png
PAS 4266 v 4274 0.1s SA.png
Avg absolute % diff 0.4% 1.9% 1.7% 33.9%
(skewed by 1 point;
otherwise it's 1.8%)
2.7%
Max % diff 8.4%, at x=0.50g 29.6%, at x=1.58g 34.3%, at x=3.98g 1448.7%, at x=2.51g 68.4%, at x=2.00g