CLR structure

The CLR structure type defines sesimological velocity models in terms of piecewise continuous polynomials, as known from standard models like PREM (Dziewonski & Anderson, 1981). Within the TTBOX context it is mainly the internal rpresentation of .clr files, which are a storage format for such models. CLR structures are currently not used for computation.

Layer information is stored as coefficients of layer polynomials. For details on the evaluation of these polynomials, see the section on the .clr format.

Its field can be divided into the following groups:

  1. General Information
  2. Layer Data
  3. Discontinuity Data
General Information
Field Type Units Description
name string - model name
year numeric - Year of model publication
planet string - Name of planet for which model is valid.
rp numeric km Radius of planet for which model is valid.
tag string - A user-defined tag with no special meaning. The user may use this as he likes. Or She.

Layer information is represented in one field which contains the number of continuously defined layers an the layers-substructure

Layer Information
Field Type Units Description
lyrcnt numeric counter Number of Layers in model.
layers structure - layers is an array of structures. Each layer has its own structure, containing the coefficients of all layer polynomials. The sequence of layers does not neccessarily correspond to the layer sequence in depth: layers(i) is not neccessarily the i-th layer from the surface or from the planets center. Depths are given by depth data only!
Layers sub-structure
Field Type Units Description
name string - name of layer (may be empty)
depth numeric 2-element vector km min(depth) is the depth to the top of the layer, measured from the surface. max(depth) is the depth of its bottom.
vp numeric n-element vector km/s P wave velocity layer polynomial coefficients. The first element is the constant term, the last element is coefficient of the highest power. A correct interpretation of the polynomial results in a velocity in km/s. The degree of the polynomial is implied by the number of coefficients.
vs numeric n-element vector km/s S wave velocity layer polynomial coefficients. The first element is the constant term, the last element is coefficient of the highest power. A correct interpretation of the polynomial results in a velocity in km/s. The degree of the polynomial is implied by the number of coefficients.
rho numeric n-element vector g/cm3 Density layer polynomial coefficients. The first element is the constant term, the last element is coefficient of the highest power. A correct interpretation of the polynomial results in a density in g/cm3. The degree of the polynomial is implied by the number of coefficients.
qp numeric n-element vector - P wave Q-factor layer polynomial coefficients. The first element is the constant term, the last element is coefficient of the highest power. A correct interpretation of the polynomial results in a dimensionless Qp factor. The degree of the polynomial is implied by the number of coefficients.
qs numeric n-element vector - S wave Q-factor layer polynomial coefficients. The first element is the constant term, the last element is coefficient of the highest power. A correct interpretation of the polynomial results in a dimensionless Qs factor. The degree of the polynomial is implied by the number of coefficients.
Discontinuity Definition Stuff
Field Type Units Description
conr numeric scalar km Depth to Conrad Discontinuity. Must be NaN if not specified.
moho numeric scalar km Depth to Mohorovicic Discontinuity. Must be NaN if not specified.
d410 numeric scalar km Depth to Olivine-α - β-spinel phase transition. Must be NaN if not specified. This is named after the mean depth on earth in order to get a short name.
d520 numeric scalar km Depth to β-spinel-&gamma-spinel phase transition. Must be NaN if not specified. This is named after the mean depth on earth in order to get a short name.
d660 numeric scalar km Depth to &gamma-spinel-Perovskite Boundary. Must be NaN if not specified. This is named after the mean depth on earth in order to get a short name.
cmb numeric scalar km Depth to the Core-Mantle-Boundary. Must be NaN if not specified.
icb numeric scalar km Depth to the Core-Mantle-Boundary. Must be NaN if not specified.
dz numeric vector km Depths of non-standard discontinuites. Must be empty if none specified.
dname string matrix - Names of non-standard discontinuities. dname(i,:) is the name string for the i-th non-standard discontinuity, the depth of which is given in dz(i). Must be empty if none specified.

eof.