Add Layer to Model - Two-Way Travel Time (TWTT)

Subdivide the model volume by inserting a new layer surface beneath an existing layer. The new layer automatically inherits all of the properties from the layer above. The property distributions in the model may be refined by assigning different properties to the new layer.

Add Layer to Model Dialog Box Options

Insert below	Select the layer beneath which the new layer will be inserted. If this action was launched by the layer context menu, this field should be correctly populated.
TWTT from	Select whether the two-way travel time (TWTT) of the layer is to be specified using a grid or a positive constant value.
	TWTT grid Specify the grid that contains the TWTT to the top of the new layer. TWTT Specify a constant TWTT for the layer.
Layer name	Enter a name for the new layer that describes it in terms of the model or geology.
Resolve crossings by:	Specify how to handle conflicts between the new layer and existing layers within the model.
Adjust new layer	Clip the new layer to the adjacent existing layers in the model, so that they are made equal in areas where they would have crossed.
Adjust model	Adjust the adjacent layer(s) to the new layer.
Don't add layer	Warn if there are potential crossings, but do not add the new layer nor adjust the new layer or the model.

Application Notes

An imported layer grid is reprojected, resampled, and clipped to match the model. If there are negative values in the grid, it will be rejected. If there are dummies within the resulting grid, they will be filled automatically if the percentage of dummy values does not exceed 25 percent. Layers are allowed to be coincident, but may never cross. There are three strategies for resolving layer-crossing conflicts:

• Adjust new layer - the new grid is clipped to the adjacent layers

• Adjust model - the new grid is clipped to the top layer (datum), and then every grid is clipped to the new layer

• Don’t add layer - the layer is rejected if any intersections are detected