Unclos Tutorial N. Sediment Thickness

Aim of this tutorial

1. Generate Sediment Profile from seismic interpretation

2. Import Sediment Thickness points from ASCII file

3. Import Sediment Thickness Grid

4. Compute Sediment points > 1% of distance to FOS

• Locate the folder “3. Sediment Data / Sediment profiles”
• Right click the folder and select “add folder”

  Add a sub folder with the name of the survey. for example “ATL-LOS-00”

• Right click the folder and select “Import -> ASCII Column…” and the ASCII Column import dialog will appear.

  Click the browse button , and select the sediment thickness file located in the Atlantis folder: “Atlantis \ Data \ ATL_Sediments.txt”

• Adjust the number of header lines in your file with the “Adjust header” Spin box to one. The header lines should be displayed in the top part of the file preview, while the bottom part of the file preview should hold the coordinates.
• Set the column separator to “whitespace”
• Select coordinate format “X Y”
• Check the “Z” and the “Scalar” Columns checkboxes
• Check the “Additional attributes”
• Type inn “Shot point” under Additional attributes, and select number, then click Add

A new column will appear for the Shot points

• Set the cell type to “Line”
• Set “Separate Data Sets” to “Value change”
• Set Schema to Sediment Thickness
• Correct file columns for each data column by adjust the spin boxes .
  x: 3
  y: 4
  z: 5
  Scalar: 6
  Shot point: 2
  Data separator: 1
• click “Execute”
• Click the “Close” button in order to close the ASCII Column import dialog
  The data has now been imported. Let us display the data:
• Right click one of the the datasets and select “Scale window to data”
• Right click the data set again, and select “Display profile as cross section”

• Open the link in your internet browser.
  Geocap should be able to import all of the formats which are presented. For this exercise you may download the “GMT NetCDF” file.
• Click the “Download GMT NetCDF grd file”. Store the file, and Unzip the grid to your hard drive.
• Locate the folder “3. Sediment Data / Grids”
  If you do not have this folder you may create it. Use the generic folder type which is the default option.
• Right click the folder and select “Import -> Generic…” and the Generic import dialog will appear.
  Click the browse button , and select the sediment thickness file.
• Click the “Area of Interest” tab.
  Here you will see extent of the file. You may specify the import area at the bottom.
• Check the import area button, type in the coordinates of your area in decimal degrees.
• Click execute.
• You will now be prompted with a question of the coordinate system and datum.
  Select: World Geodetic system 1984
  Geodetic
  Click ok
• Click close.

  The data is imported in Geodetic, with latitudes as Y coordinates and longitudes as X coordinates. In order to view the data with the other data we have imported need to convert the grid to Mercator coordinates.

• Right click the dataset and select “shared commands-> convert to Mercator”
• Change the result combo box to “Replace input”
• Click execute
  The data is now converted. Let us display the data:
• Right click the dataset and select “Scale window to data”
• Right click the dataset and select “Map”

You should now see the sediment grid in your area.

• Right click the sediment thickness data set.
• Select the command “Generate >1% of distance to FOS”
  A dialog asking for the Foot of slope data set will appear
• Browse and select the Foot of slope data-set you want to use for the calculation, click OK
  If the data-set contained any points thicker than 1% of the distance to the nearest FOS point, it will store those points in the project, and inform you of the folder used. It will also display these points.