GTL

In UCVM, geotechnical layer (GTL) refers to the near-surface region of the velocity models. These regions have significant impact on ground motion simulations.

• CVMs with GTLs : CVM-H, CVM-S4, CVM-S4.26, CVM-4.26.M01, CCA06, CS17.3, CS17.3-H

• Description of Ely-Jordan GTL method

• Ely Jordan Geotechnical layer

• Technical Description of Ely-Jordan method

How to enable/disable GTL from models

Both CVM-S4 and CVM-S4.26.M01 have builtin GTL that can not be disabled. For other models with GTL, there are two different methods for enable and disable GTL depending on the models.

CVM-H

The default GTL setting for CVM-H is off and the flag can be found in installdir/conf/ucvm.conf file.

# CVM-H model flags. The model defaults are:
# No 1D background model
# No GTL added
#
cvmh_param=USE_1D_BKG,False
cvmh_param=USE_GTL,False
#

To enable GTL, update the last line to be,

cvmh_param=USE_GTL,True

CVM-S4.26, CCA06, CS17.3, CS17.3-H

The default GTL setting for CVM-S4.26, CCA06, CS17.3 and CS17.3-H are off. The GTL setting can be set in each model's config file located at installdir/model/cvms5/data/config, installdir/model/cca/data/config, installdir/model/cs173/data/config and installdir/model/cs173h/data/config

# GTL on or off?
gtl = off 

To enable GTL, change the line to

gtl = on