CVM H GTL

CVM-H is a mult-resolution model, described this way in the USR paper (Shaw 2015).

The various components of the USR, including the topography, basin representations, basement and Moho surfaces, tomographic crust and upper mantle velocity models, and the GTL were as-sembled by parameterizing a set of voxets, or regular grids of voxels, with velocity values and by appropriately resampling sur-faces. These nested voxets include a high-resolution grid (250 by 250 m horizontally, 100 m in depth) centered around the Los Angles basin, where we had the greatest density of data. This voxet was embedded in a medium resolution grid (1 by 1km resolution, 250km in depth) for the remainder of southern California. Areas beyond the extent of the voxets are extrapolated by a 1D ve-locity model (Dreger and Helmberger, 1990; Wald et al., 1995; Hutton et al., 2010). Below 15 km, the model resolution is 1 km vertically and 10 km horizontally.

CVM-H GTL

CVM-H is a cell-based velocity model with two different resultion areas. The LA Basin area is discretized at 250x250mx100m, and the the medium resolution background region is 1kmx1kmx250m resolution.

The are three CVM-H GTL modes, which include:

Default - no GTL. The CVM-H model has limited areas with low (<500m/s) Vs values. This is the default mode.

[ucvm@66975967506b target]$ vs30_query -f /app/ucvm/conf/ucvm.conf -m cvmh < vs30pts.txt
 -118.4810    34.3120    165.039
 -118.5000    34.5000   1210.907
 -117.5000    33.5500   1424.097
 -117.5000    35.5000   1458.000
 -116.5000    34.4000   1407.656

CVM-S4 GTL. Users can edit the UCVM.conf file and set a parameter (cvmh_param=USE_GTL,True). When this is set true, CVM-H will return different material properties for the top cell. The properties it returns are based on data extracted from the CVM-S4 model, which has more detailed GTL information.

[ucvm@66975967506b target]$ vi /app/ucvm/conf/ucvm.conf
[ucvm@66975967506b target]$ vs30_query -f /app/ucvm/conf/ucvm.conf -m cvmh < vs30pts.txt
 -118.4810    34.3120    174.363
 -118.5000    34.5000    404.900
 -117.5000    33.5500    318.913
 -117.5000    35.5000    201.797
 -116.5000    34.4000    232.947

CVM-H, UCVM.conf CVM-H GTL,false

[ucvm@ac3e0e643150 target]$ ucvm_query -f /app/ucvm/conf/ucvm.conf -m cvmh < querypts.txt
Using Geo Depth coordinates as default mode.
 -118.4810    34.3120    100.000    386.051    397.973       cvmh   1946.508    505.610   1880.905       none      0.000      0.000      0.000      crust   1946.508    505.610   1880.905
 -118.5000    34.5000    100.000    573.044    527.718       cvmh   3994.835   2271.410   2392.620       none      0.000      0.000      0.000      crust   3994.835   2271.410   2392.620
 -117.5000    33.5500    100.000    381.905    518.900       cvmh   5087.308   2795.410   2548.363       none      0.000      0.000      0.000      crust   5087.308   2795.410   2548.363
 -117.5000    35.5000    100.000    721.905    394.017       cvmh   4855.963   2866.868   2513.006       none      0.000      0.000      0.000      crust   4855.963   2866.868   2513.006
 -116.5000    34.4000    100.000    791.036    293.500       cvmh   4730.289   2751.258   2494.663       none      0.000      0.000      0.000      crust   4730.289   2751.258   2494.663

images/gtl_plots/cvmh_gtl_false_no_z.png

CVM-H UCVM.conf CVM-H GTL,false, elygtl:ely -z 0,350

[ucvm@ac3e0e643150 target]$ ucvm_query -f /app/ucvm/conf/ucvm.conf -m cvmh,elygtl:ely -z 0,350 < querypts.txt
Using Geo Depth coordinates as default mode.
 -118.4810    34.3120    100.000    386.051    397.973       cvmh   2139.914    672.340   1965.082     elygtl      0.000    397.973      0.000        ely   2226.984    600.934   1999.243
 -118.5000    34.5000    100.000    573.044    527.718       cvmh   4398.315   2524.129   2448.169     elygtl      0.000    527.718      0.000        ely   3334.547   1485.425   2289.937
 -117.5000    33.5500    100.000    381.905    518.900       cvmh   5074.826   2788.256   2546.395     elygtl      0.000    518.900      0.000        ely   3609.738   1589.793   2335.911
 -117.5000    35.5000    100.000    721.905    394.017       cvmh   4860.199   2866.500   2513.634     elygtl      0.000    394.017      0.000        ely   3369.378   1523.207   2296.108
 -116.5000    34.4000    100.000    791.036    293.500       cvmh   4713.636   2738.400   2492.270     elygtl      0.000    293.500      0.000        ely   3177.536   1389.021   2260.583

images/gtl_plots/cvmh_gtl_false_elygtl_ely_z.png

CVM-H UCVM.conf CVM-H GTL,false, elygtl:linear -z 0,350

[ucvm@ac3e0e643150 target]$ ucvm_query -f /app/ucvm/conf/ucvm.conf -m cvmh,elygtl:linear -z 0,350 < querypts.txt
Using Geo Depth coordinates as default mode.
 -118.4810    34.3120    100.000    386.051    397.973       cvmh   2139.914    672.340   1965.082     elygtl      0.000    397.973      0.000     linear      0.000      0.000      0.000
 -118.5000    34.5000    100.000    573.044    527.718       cvmh   4398.315   2524.129   2448.169     elygtl      0.000    527.718      0.000     linear      0.000      0.000      0.000
 -117.5000    33.5500    100.000    381.905    518.900       cvmh   5074.826   2788.256   2546.395     elygtl      0.000    518.900      0.000     linear      0.000      0.000      0.000
 -117.5000    35.5000    100.000    721.905    394.017       cvmh   4860.199   2866.500   2513.634     elygtl      0.000    394.017      0.000     linear      0.000      0.000      0.000
 -116.5000    34.4000    100.000    791.036    293.500       cvmh   4713.636   2738.400   2492.270     elygtl      0.000    293.500      0.000     linear      0.000      0.000      0.000

images/gtl_plots/cvmh_gtl_false_elygtl_linear_z.png

CVM-H, UCVM.conf CVM-H GTL,true

[ucvm@ac3e0e643150 target]$ ucvm_query -f /app/ucvm/conf/ucvm.conf -m cvmh < querypts.txt
Using Geo Depth coordinates as default mode.
 -118.4810    34.3120    100.000    386.051    397.973       cvmh   2164.931    561.880   1975.122       none      0.000      0.000      0.000      crust   2164.931    561.880   1975.122
 -118.5000    34.5000    100.000    573.044    527.718       cvmh   3571.999   1661.088   2329.946       none      0.000      0.000      0.000      crust   3571.999   1661.088   2329.946
 -117.5000    33.5500    100.000    381.905    518.900       cvmh   3633.909   1606.619   2339.684       none      0.000      0.000      0.000      crust   3633.909   1606.619   2339.684
 -117.5000    35.5000    100.000    721.905    394.017       cvmh   3221.180   1432.285   2269.012       none      0.000      0.000      0.000      crust   3221.180   1432.285   2269.012
 -116.5000    34.4000    100.000    791.036    293.500       cvmh   3256.877   1437.267   2275.747       none      0.000      0.000      0.000      crust   3256.877   1437.267   2275.747

images/gtl_plots/cvmh_gtl_true_no_z.png

CVM-H UCVM.conf CVM-H GTL,true elygtl:ely -z 0,350

[ucvm@ac3e0e643150 target]$ ucvm_query -f /app/ucvm/conf/ucvm.conf -m cvmh,elygtl:ely -z 0,350 < querypts.txt
Using Geo Depth coordinates as default mode.
 -118.4810    34.3120    100.000    386.051    397.973       cvmh   2139.914    672.340   1965.082     elygtl      0.000    397.973      0.000        ely   2226.984    600.934   1999.243
 -118.5000    34.5000    100.000    573.044    527.718       cvmh   4398.315   2524.129   2448.169     elygtl      0.000    527.718      0.000        ely   3334.547   1485.425   2289.937
 -117.5000    33.5500    100.000    381.905    518.900       cvmh   5074.826   2788.256   2546.395     elygtl      0.000    518.900      0.000        ely   3609.738   1589.793   2335.911
 -117.5000    35.5000    100.000    721.905    394.017       cvmh   4860.199   2866.500   2513.634     elygtl      0.000    394.017      0.000        ely   3369.378   1523.207   2296.108
 -116.5000    34.4000    100.000    791.036    293.500       cvmh   4713.636   2738.400   2492.270     elygtl      0.000    293.500      0.000        ely   3177.536   1389.021   2260.583

images/gtl_plots/cvmh_gtl_true_elygtl_ely_z.png

CVM-H UCVM.conf CVM-H GTL,true elygtl:linear -z 0,350

[ucvm@ac3e0e643150 target]$ ucvm_query -f /app/ucvm/conf/ucvm.conf -m cvmh,elygtl:linear -z 0,350 < querypts.txt
Using Geo Depth coordinates as default mode.
 -118.4810    34.3120    100.000    386.051    397.973       cvmh   2139.914    672.340   1965.082     elygtl      0.000    397.973      0.000     linear      0.000      0.000      0.000
 -118.5000    34.5000    100.000    573.044    527.718       cvmh   4398.315   2524.129   2448.169     elygtl      0.000    527.718      0.000     linear      0.000      0.000      0.000
 -117.5000    33.5500    100.000    381.905    518.900       cvmh   5074.826   2788.256   2546.395     elygtl      0.000    518.900      0.000     linear      0.000      0.000      0.000
 -117.5000    35.5000    100.000    721.905    394.017       cvmh   4860.199   2866.500   2513.634     elygtl      0.000    394.017      0.000     linear      0.000      0.000      0.000
 -116.5000    34.4000    100.000    791.036    293.500       cvmh   4713.636   2738.400   2492.270     elygtl      0.000    293.500      0.000     linear      0.000      0.000      0.000

images/gtl_plots/cvmh_gtl_true_elygtl_linear_z.png

Examples Effect of Ely/Jordan GTL in vs30queries

[ucvm@28d7188735e6 target]$ vs30_query -f /app/ucvm/conf/ucvm.conf -m cvms5 < vs30pts.txt
 -118.4810    34.3120    479.035
 -118.5000    34.5000    542.880
 -117.5000    33.5500   1488.633
 -117.5000    35.5000   1301.073
 -116.5000    34.4000   1297.697
[ucvm@28d7188735e6 target]$ vs30_query -f /app/ucvm/conf/ucvm.conf -m cvms5,elygtl:ely -z 0,350 < vs30pts.txt
 -118.4810    34.3120    209.404
 -118.5000    34.5000    276.783
 -117.5000    33.5500    313.116
 -117.5000    35.5000    246.636
 -116.5000    34.4000    200.306
[ucvm@28d7188735e6 target]$ vs30_query -f /app/ucvm/conf/ucvm.conf -m cvms5,elygtl:linear -z 0,350 < vs30pts.txt
 -118.4810    34.3120      0.000
 -118.5000    34.5000      0.000
 -117.5000    33.5500      0.000
 -117.5000    35.5000      0.000
 -116.5000    34.4000      0.000

Show that the CVM-H USE_GTL model flag in ucvm.conf has effect

The user can specify whether a geotechnical layer, based on Ely Vs30 technique is added to the top 300M of the cvm-h model, by editing a flag in the ucvm.conf file. We expect that Vs values in the top 300m will be lower for sites when the USE_GTL flag is set to true. We called ucvm_query this way:

./bin/ucvm_query -f ./conf/ucvm.conf -m cvmh -c gd < ./tests/inputs/ucvm_socal_test_pts.txt > ucvm_cvmh_depth_usegtl_false_results.txt

We ran this query without USE_GTL by setting conf/ucvm.conf file flag this way:

cvmh_param=USE_1D_BKG,False
cvmh_param=USE_GTL,False

We ran this query with USE_GTL by setting conf/ucvm.conf file flag this way:

cvmh_param=USE_1D_BKG,False
cvmh_param=USE_GTL,True

We posted the results on a SCEC Website at:

This shows the the USE_GTL flag return different material properties in the top 500m. However, the columns showing combined results (from model and GTL) are identical. This suggests that the combined properties columns change only when an external GTL is returned from the UCVM. CVM-H internal GTL does not appear as a "combined" material properties, but rather as native model properties.

Shield: