Unclos Tutorial I. Foot Of Slope (FOS) Points

• Right click the profile you generated in the previous exercise
• Select the command object called “Analyze Profile”

  The profile analysis tool will appear at the bottom of your screen. You may need to give some more space to it in order to see it properly.

  The black line with gray dots is the seafloor. The red dotted line is the change of gradient. The red vertical line marks the point of the maximum change of gradient on your profile.
  You may also see the same profile in the 3D window. The red vertical line is marked there as well.

• If you want to flip the direction of the profile in the 2D window, you may do so with the “flip profile direction” button.
• Click the select area button
• Click with the left mouse button in the profile window, and keep the left button pressed.
  Drag the mouse to the side, and release the button.
  This is how you select the area where the software will calculate the change of gradient.

  If you do not use an “evidence to the contrary”, the foot of the continental slope should be placed at maximum change of gradient at the base of the slope. So we want to restrict the calculation of the change of gradient to the “base of the slope”. Determining the “Base of the Slope” may be quite complicated, and we will not go into details about that in this tutorial.

• Click the select area button again, and select the part of the profile which you want to use as the base of the slope.

  You may do several changes to the parameters of the algorithm. But for this exercise, we will just keep the default settings.

• Click the “New Analysis” button. This will store the analysis, and the foot of slope point.
• Click the plus sign next to the profile in the project manager, and you will see that the FOS analysis is stored as a child of the profile in the tree.
• Click the plus sign next to the “FOS analysis” dataset, and you will see the “Foot of Slope” dataset. This is the data set holding the foot of slope point we just made.
• Click the “Exit” button in the bathymetric profile Dialog in order to close it.

It is often useful to work with a group of FOS points, instead of working with them individually. This exercise will show you how you can collect many FOS points into one foot of slope data set.

• A foot of slope point is stored as a dataset under an analysis which again is stored under a profile. Click the small plus signs to the right of the profiles and the analysis datasets, you have made in the previous exercises, so that the foot of slope points appear.
• Right click the first foot of slope point, and select the command “set as active foot of slope”
• Right click the next foot of slope point and select the command “Append to active foot of slope”
• Repeat the last step, and append all the foot of slope points you want to collect.
• Right click the folder “2. Seabed” and select “Add-> Folder”
  The New Folder dialog will appear
• Select the Generic type (which is default choice)
• Select the name to be “Foot Of Slope”
• Click ok
• Right click the new folder (“Foot of slope”) and select “add-> Workspace data -> fos”
• The Foot of Slope collection is now added to the folder.
• Right click the new dataset and select “Set Schema-> Foot of Slope”
• Right click the same dataset again and select “Rename”

Give the foot of slope a proper name, for example the area you are working in.

• Display the FOS points which you created in the previous exercise.
• Right-click the dataset and select the command object “Generate 60M Line”
• The new line should now be available under “1. Maritime Lines/60M Lines”
• Display the 60M line
• When you have made changes to the project it is always a good idea to store them. Click the save button: in the project tool bar in order to save your project.