SCECpedia - User contributions [en]

BBP Group Ridgecrest Sequence Simulations

2020-09-10T18:07:29Z

Goulet: /* Observational Data */

This page documents the BBP Group activities to simulate events from the Ridgecrest Sequence.

== Events Considered ==
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38443183/moment-tensor USGS Event page for M6.4 (RIDG19A)]
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38450263/moment-tensor USGS Event page for M5.4 (RIDG19B)]
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38457511/moment-tensor USGS Event page for M7.1 (RIDG19C)]

* [http://hypocenter.usc.edu/research/Goulet/BBP_RidgecrestSequence/2019RidgEqSeq_Ridg19_Flatfile_RotD50_050_EventParameters.xlsx Source information from NGA-NHR3 preliminary release]

== Observational Data ==
* [http://hypocenter.usc.edu/research/Goulet/BBP_RidgecrestSequence/2019RidgEqSeq_NGA_Datasets_20200609.kmz Google Earth map of NGA-NHR3-processed data available as of 2020-06-09]
* [http://hypocenter.usc.edu/research/Goulet/BBP_RidgecrestSequence/GEFileVs30map_FaultTraces_Ridgecrest_All3NonRepeat_name.kml Google Earth map of Vs30 at recording stations (triangles=measured and circles=inferred)]

== Station Selection ==
* For the validation, Christine selected all the stations within a closest distance (Rrup) of 125 km of all three events. This yielded ~ 50 stations, most of which have recordings for all three events.

== SRC Files ==

=== M5.4 ===

MAGNITUDE = 5.36
LAT_TOP_CENTER = 35.757359
LON_TOP_CENTER = -117.566269
DEPTH_TO_TOP = 6.0
STRIKE = 313
DIP = 81
RAKE = -165
FAULT_LENGTH = 3.0
DLEN = 0.1
FAULT_WIDTH = 3.0
DWID = 0.1
HYPO_ALONG_STK = 0.0
HYPO_DOWN_DIP = 1.5
SEED = ***needs_to_be_specified_and_different_than_other_segments_and_hypos***
MAX_FAULT_LENGTH = 3
RUPTURE_DELAY = 0.00
MOMENT_FRACTION = 1

BBP Group Ridgecrest Sequence Simulations

2020-06-25T00:06:06Z

Goulet: /* Station Selection */

This page documents the BBP Group activities to simulate events from the Ridgecrest Sequence.

== Events Considered ==
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38443183/moment-tensor USGS Event page for M6.4 (RIDG19A)]
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38450263/moment-tensor USGS Event page for M5.4 (RIDG19B)]
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38457511/moment-tensor USGS Event page for M7.1 (RIDG19C)]

* [http://hypocenter.usc.edu/research/Goulet/BBP_RidgecrestSequence/2019RidgEqSeq_Ridg19_Flatfile_RotD50_050_EventParameters.xlsx Source information from NGA-NHR3 preliminary release]

== Observational Data ==
* [http://hypocenter.usc.edu/research/Goulet/BBP_RidgecrestSequence/2019RidgEqSeq_NGA_Datasets_20200609.kmz Google Earth map of NGA-NHR3-processed data available as of 2020-06-09]

== Station Selection ==
* For the validation, Christine selected all the stations within a closest distance (Rrup) of 125 km of all three events. This yielded ~ 50 stations, most of which have recordings for all three events.

== SRC Files ==

=== M5.4 ===

MAGNITUDE = 5.36
LAT_TOP_CENTER = 35.757359
LON_TOP_CENTER = -117.566269
DEPTH_TO_TOP = 6.0
STRIKE = 313
DIP = 81
RAKE = -165
FAULT_LENGTH = 3.0
DLEN = 0.1
FAULT_WIDTH = 3.0
DWID = 0.1
HYPO_ALONG_STK = 0.0
HYPO_DOWN_DIP = 1.5
SEED = ***needs_to_be_specified_and_different_than_other_segments_and_hypos***
MAX_FAULT_LENGTH = 3
RUPTURE_DELAY = 0.00
MOMENT_FRACTION = 1

2020-06-18T22:51:25Z

Goulet: /* Events Considered */

This page documents the BBP Group activities to simulate events from the Ridgecrest Sequence.

== Events Considered ==
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38443183/moment-tensor USGS Event page for M6.4 (RIDG19A)]
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38450263/moment-tensor USGS Event page for M5.4 (RIDG19B)]
* [https://earthquake.usgs.gov/earthquakes/eventpage/ci38457511/moment-tensor USGS Event page for M7.1 (RIDG19C)]

Source information from NHR3 preliminary release

== Observational Data ==
* [http://hypocenter.usc.edu/research/Goulet/BBP_RidgecrestSequence/2019RidgEqSeq_NGA_Datasets_20200609.kmz Google Earth map of NGA-processed data available as of 2020-06-09]

== Station Selection ==
* For the validation, we select the 50 stations closest to the hypocenter of the M5.4 event

== SRC Files ==

=== M5.4 ===

MAGNITUDE = 5.36
LAT_TOP_CENTER = 35.757359
LON_TOP_CENTER = -117.566269
DEPTH_TO_TOP = 6.0
STRIKE = 313
DIP = 81
RAKE = -165
FAULT_LENGTH = 3.0
DLEN = 0.1
FAULT_WIDTH = 3.0
DWID = 0.1
HYPO_ALONG_STK = 0.0
HYPO_DOWN_DIP = 1.5
SEED = ***needs_to_be_specified_and_different_than_other_segments_and_hypos***
MAX_FAULT_LENGTH = 3
RUPTURE_DELAY = 0.00
MOMENT_FRACTION = 1

2020-04-13T23:55:13Z

Goulet:

This page documents the High-F activities and decisions for the 2018 verification and validation runs for three groups: Olsen et al. (AWP), Graves (RWG) and Taborda et al. (Hercules).

== Mesh generation rules and parameter constraints ==
=== Domain definitions ===
Small domain: defined [https://scec.usc.edu/scecpedia/La_Habra_Simulation_Region here].
Large domain: defined [https://scec.usc.edu/scecpedia/HighF_v14.12#Simulation_Box_.2F_Velocity_Model here].

Use CVMS4.26.M01 (called cvmsi in UCVM, as per Table 1 in this [http://hypocenter.usc.edu/research/High-F_2020/Small_et_al_2017_SCEC_UCVM.pdf UCVM paper]), do NOT apply a GTL to the model, but apply the rules described below.

=== Velocities ===
* 1. Set Min Vs=500 m/s
* 2. If Vs was lower than 500 m/s and adjusted, then adjust Vp with original Vp/Vs ratio (so that we don’t have the automatic Vs/Vp of 3). We may want to set a minimum value of Vp (Rob to check)
* 3. Then set Max Vp/Vs= 3, if lower Vp to maintain the max of 3 ratio

=== Lame parameters (mu and lambda) ===
Use mu and Lambda parameters to fix Vp/Vs issues in the CVM where necessary, as part of the mesh generation. Need to make sure that patches are physical and not only to make the codes run.
* Rob to check if raw model produces lambda of <=zero.
* Note: lambda of zero corresponds to Vp/Vs= sqrt(2)=1.45
* Note: typical Vp speeds are 330 m/s in air, 1450 m/s in water and about 5000 m/s in granite

=== Anelastic attenuation (Q) ===
Frequency-independent Q definition
* Qs=100*Vs(km/s)
* Qp=2*Qs

=== Upper frequency ===

* 5Hz: based on 500 m/s and 20 m spacing
* Kim and Rob have been low-pass filtering the slip function at 5 Hz
* Ricardo and Naeem don’t filter the source

== Source Models ==
We discussed various sources, both point source (PS) and finite-fault (FF) in the past for our verifications and validation.
* Various models were run in 2016:
** [https://scec.usc.edu/scecpedia/HighF_v14.12_Data_Comparison#Simulation_Results_-_22_May_2016 2016 runs with 2FF and 1 PS]

* Also ran various smoothed variations of the GP15 FF (need to find a reference for that)

* Rob to follow-up with Wei (last communication was in April 2017).

Proposed models for verification and validation:
*PS: model from En-Jui (moment tensor). Can we replicate En-Jui's results? Would need to use CVMS4.26 (cms5) - not desirable. We could perform a check with CVS4.26.M01 at 5 sec. Need to use the same record En-Jui used. Proposed to use records from Figure 6 in:
** Lee E.-J., P. Chen, and T.H. Jordan (2014). Testing Waveform Predictions of 3D Velocity Models against Two Recent Los Angeles Earthquakes. Seismol. Res. Lett., 85 (6): 1275–1284 ([http://hypocenter.usc.edu/var/www/html/research/High-F_2018/Lee%2C%20Chen%2C%20Jordan%20-%202014%20-%20Testing%20Waveform%20Predictions%20of%203D%20Velocity%20Models%20against%20Two%20Recent%20Los%20Angeles%20Earthquakes.pdf Paper here])
*FF: [http://hypocenter.usc.edu/research/High-F_2018/LaHabra_notes-20170412-presented-2017-04-24.pdf Summary of agreed-upon FF model (gp.5.3.02)]
* FF refined with velocity model [http://hypocenter.usc.edu/research/High-F_2018/rwg_slides-20180221.pptx Slides from Graves presented on Feb. 21 2018]

2020 updates:
* Revisiting finite fault selection for the verification paper
** Rob ran a series of tests to select a finite source to use with the Vmod floored at 500 m/s ([http://hypocenter.usc.edu/research/High-F_2020/source_nearfault-20200217.pptx powerpoint here])
** The suite of 40 SRF rupture models for the 2.5 km X 2.5 km fault are contained in this [http://hypocenter.usc.edu/research/High-F_2020/m5.14-2.5x2.5.tgz tarfile (364 MB)]. There are 2 resolutions: 100 m subfaults and 20m subfaults. The recommendation is to use 20m subfaults if possible.

== Site Selection ==
2020 updates
* Step 1: fault model verification to be done by all groups, using the "small domain", focused on near-by stations selected by Rob (need to link to text file here)

== Simulation results ==
=== Results shared on March 5 2018 ===
Description: results for the small region from November 10 2017:

Description: small region simulations for Hercules, AWP (updated since November 2017) and RWG (medium size model to avoid boundary reflexions):

* [http://hypocenter.usc.edu/bbp/highf/awp-hercules-rwg-2018-03-05 AWP-Hercules-RWG Comparison]
* [http://hypocenter.usc.edu/bbp/highf/obs-awp-hercules-rwg-2018-03-05 AWP-Hercules-RWG Comparison With Observations]

=== Results shared on March 12 2018 ===
Description: results for the small region from November 10 2017:

Description: small region simulations for Hercules (updated to use simulations including Q), AWP (updated since November 2017) and RWG (medium size model to avoid boundary reflexions):

* [http://hypocenter.usc.edu/bbp/highf/awp-hercules-rwg-2018-03-12 AWP-Hercules-RWG Comparison]
* [http://hypocenter.usc.edu/bbp/highf/bbp_comparison/awp-hercules-rwg-2018-03-12 AWP-Hercules-RWG Timeseries Comparison]

== 2019-12-02 Call, summary of plans for 2020==

=== Goals for 2020 ===
** Verification paper (2020 Q1+?)
** Validation paper(s) (2020 Q2+?)

=== Action items from call ===
* Rob to test other finite fault models using near-fault data and perform initial screening of candidate sources
* Christine to coordinate with Phil and Fabio for Jan. High-F sprint
** to allow use of BBP GOF post-processors with high-f results and data
** to revive GOF map plotting tools (last run in 2016)
** Christine to verify that PSA results are ok (see anomaly on 20181125 results for observations of CE_13066).
** need to confirm start time as documented in post-processing code. Is it more or less constant with offset at all stations?
* Christine to re-start verification paper development
* Group need to document their submissions for point source or rerun them (see section below; finite fault is documented).

=== Latest 2018 results documentation ===
Description: results for the small and large regions (model dependent) from November 10 2017, computed 20181125 using the latest ts_processor codes:

* [http://hypocenter.usc.edu/bbp/highf/obs-awp-hercules-rwg-2018-11-25-vel/ AWP-Hercules-RWG-OBS Comparison]

Summary documentation of extended source simulations submitted at [http://hypocenter.usc.edu/research/highf_data/ high-f]:

Hercules 20171106 notes:
* Simulation of Mw 5.14 Lahabra Earthquake.(2014/03/29 04:09:42.97) with damping and using the extended source model provided by Robert Graves (downsampled version of the SRF for La Habra and based on 3D velocity model.The subfault spacing is 100 m). This simulation is part of High-F project. The simulation is done using the CVM-etree extracted from CVM-S4.26.M01 (28*28*14 km) at the “Small Domain." See readme.txt in their folder for more info.

RWG 20180425 notes:
* 20180425 - RWG simulation results for full-size model region (135 km x 180 km x 60 km). Velocity mesh was created on BlueWaters using UCVM interface that Scott C. created. Model is CVM-S4.26.M01 (at least I believe so, I selected 'cvmsi' as input to single_exe.py). Vp/Vs capped at 3.0, Vsmin=500 ms, Qs=100*Vs(m/s), Qp=2*Qs. Time step is dt=0.001 sec. Waveforms are ground velocity and have been low-pass filtered using zero-phase 4th order butterworth with corner at 5 Hz.

AWP 20181203 notes:
* The latest anelastic simulation using cap of vp/vs=3, minimum Vs at 500 m/s with simulation length to 120 seconds in the large domain (180 km * 135 km * 60 km, grid spacing = 20 m). Number of stations: 351.

== 2020-03-16 call summary: path forward on VERIFICATION paper ==
Verification of 5 Hz time series (4Hz PSA, multiple bands verification):
* Use Vs floor of 500 m/s (CVMS4.26-M01 (cmvsi))
* Use RWG best source
* Verify that best RG source is good at 17 stations for all models
* Then all modelers rerun large region (need to confer on rotations before that step)
* Perform verification using results and plots from
** Seismtools
** tsprocess Anderson GOF scores and maps (GMT capability needs to be restored due to updates)
** BBP (GOF with T, distance, mapped, etc.; consider adding Vs30-based plots on BBP)
* Compare with 1D BBP sims (with Vs30=500 for all stations, with site response)?
* Write paper, publish

== Related Pages ==
*[https://scec.usc.edu/scecpedia/High-F_Project High-F Main page]

*[https://scec.usc.edu/scecpedia/HighF_v14.12_Data_Comparison Past verification (HighF_v14.12_Data)]

*[https://scec.usc.edu/scecpedia/La_Habra_Simulations_on_Titan La Habra simulations on Titan]

*[https://scec.usc.edu/scecpedia/La_Habra_Simulation_Region La Habra Simulation region]
*[https://scec.usc.edu/scecpedia/La_Habra_Observational_Data La Habra Observational data]