Tools

We have a number of functions with which we can extract sub-data from a 2D or 3D GeoData structure.

GeophysicalModelGenerator.CrossSectionFunction
CrossSection(DataSet::GeoData; dims=(100,100), Interpolate=false, Depth_level=nothing; Lat_level=nothing; Lon_level=nothing; Start=nothing, End=nothing )

Creates a cross-section through a GeoData object.

  • Cross-sections can be horizontal (map view at a given depth), if Depth_level is specified
  • They can also be vertical, either by specifying Lon_level or Lat_level (for a fixed lon/lat), or by defining both Start=(lon,lat) & End=(lon,lat) points.
  • Depending on the type of input data (volume, surface or point data), cross sections will be created in a different manner:
  1. Volume data: data will be interpolated or directly extracted from the data set.
  2. Surface data: surface data will be interpolated or directly extracted from the data set
  3. Point data: data will be projected to the chosen profile. Only data within a chosen distance (default is 50 km) will be used
  • Interpolate indicates whether we want to simply extract the data from the data set (default) or whether we want to linearly interpolate it on a new grid, which has dimensions as specified in dims NOTE: THIS ONLY APPLIES TO VOLUMETRIC aND SURFACE DATA SETS
  • 'section_width' indicates the maximal distance within which point data will be projected to the profile

Example:

julia> Lon,Lat,Depth   =   LonLatDepthGrid(10:20,30:40,(-300:25:0)km);
julia> Data            =   Depth*2;                # some data
julia> Vx,Vy,Vz        =   ustrip(Data*3),ustrip(Data*4),ustrip(Data*5);
julia> Data_set3D      =   GeoData(Lon,Lat,Depth,(Depthdata=Data,LonData=Lon, Velocity=(Vx,Vy,Vz))); 
julia> Data_cross      =   CrossSection(Data_set3D, Depth_level=-100km)  
GeoData 
  size  : (11, 11, 1)
  lon   ϵ [ 10.0 : 20.0]
  lat   ϵ [ 30.0 : 40.0]
  depth ϵ [ -100.0 km : -100.0 km]
  fields: (:Depthdata, :LonData, :Velocity)
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GeophysicalModelGenerator.ExtractSubvolumeFunction
ExtractSubvolume(V::GeoData; Interpolate=false, Lon_level=nothing, Lat_level=nothing, Depth_level=nothing, dims=(50,50,50))

Extract or "cuts-out" a piece of a 2D or 3D GeoData set, defined by Lon, Lat and Depth coordinates.

This is useful if you are only interested in a part of a much bigger larger data set.

  • Lon_level,Lat_level and Depth_level should be tuples that indicate (minimum_value, maximum_value) along the respective direction. If not specified we use the full range.
  • By default, Interpolate=false and we find the closest indices within the data set (so your new data set will not go exactly from minimum to maximum).
  • Alternatively, if Interpolate=true we interpolate the data onto a new grid that has dimensions dims. This can be useful to compare data sets that are originally given in different resolutions.

3D Example with no interpolation:

julia> Lon,Lat,Depth   =   LonLatDepthGrid(10:20,30:40,(-300:25:0)km);
julia> Data            =   Depth*2;                # some data
julia> Vx,Vy,Vz        =   ustrip(Data*3),ustrip(Data*4),ustrip(Data*5);
julia> Data_set3D      =   GeoData(Lon,Lat,Depth,(Depthdata=Data,LonData=Lon, Velocity=(Vx,Vy,Vz)))
GeoData 
  size  : (11, 11, 13)
  lon   ϵ [ 10.0 : 20.0]
  lat   ϵ [ 30.0 : 40.0]
  depth ϵ [ -300.0 km : 0.0 km]
  fields: (:Depthdata, :LonData, :Velocity)
julia> Data_extracted = ExtractSubvolume(Data_set3D,Lon_level=(10,12),Lat_level=(35,40))
GeoData 
  size  : (3, 6, 13)
  lon   ϵ [ 10.0 : 12.0]
  lat   ϵ [ 35.0 : 40.0]
  depth ϵ [ -300.0 km : 0.0 km]
  fields: (:Depthdata, :LonData, :Velocity)

By default it extracts the data points closest to the area defined by Lonlevel/Latlevel/Depth_level.

3D Example with interpolation:

Alternatively, you can also interpolate the data onto a new grid:

julia> Data_extracted = ExtractSubvolume(Data_set3D,Lon_level=(10,12),Lat_level=(35,40), Interpolate=true, dims=(50,51,52))
GeoData 
  size  : (50, 51, 52)
  lon   ϵ [ 10.0 : 12.0]
  lat   ϵ [ 35.0 : 40.0]
  depth ϵ [ -300.0 km : 0.0 km]
  fields: (:Depthdata, :LonData, :Velocity)
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GeophysicalModelGenerator.InterpolateDataFieldsFunction
InterpolateDataFields(V::AbstractGeneralGrid, Lon, Lat, Depth)

Interpolates a data field V on a grid defined by Lon,Lat,Depth

Example

julia> x        =   0:2:10
julia> y        =   -5:5
julia> z        =   -10:2:2
julia> X,Y,Z    =   XYZGrid(x, y, z);
julia> Data     =   Z
julia> Data_set1=   CartData(X,Y,Z, (FakeData=Data,Data2=Data.+1.))
CartData 
    size    : (6, 11, 7)
    x       ϵ [ 0.0 km : 10.0 km]
    y       ϵ [ -5.0 km : 5.0 km]
    z       ϵ [ -10.0 km : 2.0 km]
    fields  : (:FakeData, :Data2)
  attributes: ["note"]
  
julia> X,Y,Z    =   XYZGrid(0:4:10, -1:.1:1, -5:.1:1 );
julia> Data_set2= InterpolateDataFields(Data_set1, X,Y,Z)
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InterpolateDataFields(V::UTMData, EW, NS, Depth)

Interpolates a data field V on a grid defined by UTM,Depth

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GeophysicalModelGenerator.VoteMapFunction
VoteMap(DataSets::Vector{GeoData}, criteria::Vector{String}, dims=(50,50,50))

Creates a Vote map which shows consistent features in different 2D/3D tomographic datasets.

The way it works is:

  • Find a common region between the different GeoData sets (overlapping lon/lat/depth regions)
  • Interpolate the fields of all DataSets to common coordinates
  • Filter data points in one model (e.g., areas with a velocity anomaly > 2 percent). Set everything that satisfies this criteria to 1 and everything else to 0.
  • Sum the results of the different datasets

If a feature is consistent between different datasets, it will have larger values.

Example

We assume that we have 2 seismic velocity datasets Data_Zhao_Pwave and DataKoulakov_Alps:

julia> Data_Zhao_Pwave
GeoData 
  size  : (121, 94, 101)
  lon   ϵ [ 0.0 : 18.0]
  lat   ϵ [ 38.0 : 51.95]
  depth ϵ [ -1001.0 km : -1.0 km]
  fields: (:dVp_Percentage,)
julia> DataKoulakov_Alps
  GeoData 
    size  : (108, 81, 35)
    lon   ϵ [ 4.0 : 20.049999999999997]
    lat   ϵ [ 37.035928143712574 : 49.01197604790419]
    depth ϵ [ -700.0 km : -10.0 km]
    fields: (:dVp_percentage, :dVs_percentage)

You can create a VoteMap which combines the two data sets with:

julia> Data_VoteMap = VoteMap([Data_Zhao_Pwave,DataKoulakov_Alps],["dVp_Percentage>2.5","dVp_percentage>3.0"])
GeoData 
  size  : (50, 50, 50)
  lon   ϵ [ 4.0 : 18.0]
  lat   ϵ [ 38.0 : 49.01197604790419]
  depth ϵ [ -700.0 km : -10.0 km]
  fields: (:VoteMap,)

You can also create a VoteMap of a single dataset:

julia> Data_VoteMap = VoteMap(Data_Zhao_Pwave,"dVp_Percentage>2.5", dims=(50,51,52))
GeoData 
  size  : (50, 51, 52)
  lon   ϵ [ 0.0 : 18.0]
  lat   ϵ [ 38.0 : 51.95]
  depth ϵ [ -1001.0 km : -1.0 km]
  fields: (:VoteMap,)
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GeophysicalModelGenerator.SubtractHorizontalMeanFunction
V_sub = SubtractHorizontalMean(V::AbstractArray{T, 3}; Percentage=false)

Subtracts the horizontal average of the 3D data array V.

If Percentage=true, the result is given as percentage; otherwise absolute values are returned

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V_sub = SubtractHorizontalMean(V::AbstractArray{T, 2}; Percentage=false)

Subtracts the horizontal average of the 2D data array V.

If Percentage=true, the result is given as percentage; otherwise absolute values are returned

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GeophysicalModelGenerator.AboveSurfaceFunction
AboveSurface(Data::GeoData, DataSurface::GeoData; above=true)

Returns a boolean array of size(Data.Lon), which is true for points that are above the surface DataSurface (or for points below if above=false).

This can be used, for example, to mask points above/below the Moho in a volumetric dataset or in a profile.

Example

First we create a 3D data set and a 2D surface:

julia> Lon,Lat,Depth   =   LonLatDepthGrid(10:20,30:40,(-300:25:0)km);
julia> Data            =   Depth*2; 
julia> Data_set3D      =   GeoData(Lon,Lat,Depth,(Depthdata=Data,LonData=Lon))
GeoData 
  size  : (11, 11, 13)
  lon   ϵ [ 10.0 : 20.0]
  lat   ϵ [ 30.0 : 40.0]
  depth ϵ [ -300.0 km : 0.0 km]
  fields: (:Depthdata, :LonData)
julia> Lon,Lat,Depth   =   LonLatDepthGrid(10:20,30:40,-40km);  
julia> Data_Moho       =   GeoData(Lon,Lat,Depth+Lon*km, (MohoDepth=Depth,))
  GeoData 
    size  : (11, 11, 1)
    lon   ϵ [ 10.0 : 20.0]
    lat   ϵ [ 30.0 : 40.0]
    depth ϵ [ -30.0 km : -20.0 km]
    fields: (:MohoDepth,)

Next, we intersect the surface with the data set:

julia> Above       =   AboveSurface(Data_set3D, Data_Moho); 

Now, Above is a boolean array that is true for points above the surface and false for points below and at the surface.

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Above = AboveSurface(Data_Cart::ParaviewData, DataSurface_Cart::ParaviewData; above=true)

Determines if points within the 3D Data_Cart structure are above the Cartesian surface DataSurface_Cart

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Above = AboveSurface(Data_Cart::CartData, DataSurface_Cart::CartData; above=true)

Determines if points within the 3D Data_Cart structure are above the Cartesian surface DataSurface_Cart

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Above = AboveSurface(Grid::CartGrid, DataSurface_Cart::CartData; above=true)

Determines if points described by the Grid CartGrid structure are above the Cartesian surface DataSurface_Cart

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Above = AboveSurface(Data_LaMEM::LaMEM_grid, DataSurface_Cart::CartData)

Determines if points within the 3D LaMEM_grid structure are above the Cartesian surface DataSurface_Cart

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GeophysicalModelGenerator.BelowSurfaceFunction
Below = BelowSurface(Data::GeoData, DataSurface::GeoData)

Determines if points within the 3D Data structure are below the GeoData surface DataSurface

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Below = BelowSurface(Grid::CartGrid, DataSurface_Cart::CartData)

Determines if points described by the `Grid` CartGrid structure are above the Cartesian surface `DataSurface_Cart`
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Below = BelowSurface(Data_Cart::ParaviewData, DataSurface_Cart::ParaviewData)

Determines if points within the 3D DataCart structure are below the Cartesian surface DataSurfaceCart

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Below = BelowSurface(Data_Cart::CartData, DataSurface_Cart::CartData)

Determines if points within the 3D DataCart structure are below the Cartesian surface DataSurfaceCart

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Below = BelowSurface(Data_LaMEM::LaMEM_grid, DataSurface_Cart::CartData)

Determines if points within the 3D LaMEM_grid structure are below the Cartesian surface DataSurface_Cart

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GeophysicalModelGenerator.InterpolateDataOnSurfaceFunction
Surf_interp = InterpolateDataOnSurface(V::ParaviewData, Surf::ParaviewData)

Interpolates a 3D data set V on a surface defined by Surf. nex

Example

julia> Data
ParaviewData 
  size  : (33, 33, 33)
  x     ϵ [ -3.0 : 3.0]
  y     ϵ [ -2.0 : 2.0]
  z     ϵ [ -2.0 : 0.0]
  fields: (:phase, :density, :visc_total, :visc_creep, :velocity, :pressure, :temperature, :dev_stress, :strain_rate, :j2_dev_stress, :j2_strain_rate, :plast_strain, :plast_dissip, :tot_displ, :yield, :moment_res, :cont_res)
julia> surf
ParaviewData 
  size  : (96, 96, 1)
  x     ϵ [ -2.9671875 : 3.2671875]
  y     ϵ [ -1.9791666666666667 : 1.9791666666666667]
  z     ϵ [ -1.5353766679763794 : -0.69925457239151]
  fields: (:Depth,)
julia> Surf_interp = InterpolateDataOnSurface(Data, surf)
  ParaviewData 
    size  : (96, 96, 1)
    x     ϵ [ -2.9671875 : 3.2671875]
    y     ϵ [ -1.9791666666666667 : 1.9791666666666667]
    z     ϵ [ -1.5353766679763794 : -0.69925457239151]
    fields: (:phase, :density, :visc_total, :visc_creep, :velocity, :pressure, :temperature, :dev_stress, :strain_rate, :j2_dev_stress, :j2_strain_rate, :plast_strain, :plast_dissip, :tot_displ, :yield, :moment_res, :cont_res)
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Surf_interp = InterpolateDataOnSurface(V::GeoData, Surf::GeoData)

Interpolates a 3D data set V on a surface defined by Surf

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GeophysicalModelGenerator.ParseColumns_CSV_FileFunction
ParseColumns_CSV_File(data_file, num_columns)

This parses numbers from CSV file that is read in with CSV.File. That is useful in case the CSV files has tables that contain both strings (e.g., station names) and numbers (lat/lon/height) and you are only intested in the numbers

Example

This example assumes that the data starts at line 18, that the colums are separated by spaces, and that it contains at most 4 columns with data:

julia> using CSV
julia> data_file        =   CSV.File("FileName.txt",datarow=18,header=false,delim=' ')
julia> data = ParseColumns_CSV_File(data_file, 4)
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Missing docstring.

Missing docstring for GeophysicalModelGenerator.RotateTranslateScale!. Check Documenter's build log for details.

Missing docstring.

Missing docstring for GeophysicalModelGenerator.Convert2UTMzone. Check Documenter's build log for details.

Missing docstring.

Missing docstring for GeophysicalModelGenerator.Convert2CartData. Check Documenter's build log for details.

Missing docstring.

Missing docstring for GeophysicalModelGenerator.ImportTopo. Check Documenter's build log for details.

Missing docstring.

Missing docstring for GeophysicalModelGenerator.ProjectCartData. Check Documenter's build log for details.

GeophysicalModelGenerator.DrapeOnTopoFunction
Topo = DrapeOnTopo(Topo::GeoData, Data::GeoData)

This drapes fields of a data set Data on the topography Topo

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DrapeOnTopo(Topo::CartData, Data::CartData)

Drapes Cartesian Data on topography

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GeophysicalModelGenerator.LithostaticPressure!Function
LithostaticPressure!(Plithos::Array, Density::Array, dz::Number; g=9.81)

Computes lithostatic pressure from a 3D density array, assuming constant soacing dz in vertical direction. Optionally, the gravitational acceleration g can be specified.

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