Snap (Horizon)

Use the Snap operation to shift horizon points to a specific part of the waveform: positive peak, negative trough, zero-crossing increasing, or zero-crossing decreasing.

Note: The Snap Horizon button will be disabled if the horizon you are using in the operation is pending on another operation such as propagation. You will see a notification of the pending operation that you should complete before continuing with the current operation.

Where is the snap operation?

Snap is found in the Map View, under the Operations tab (along with other horizon operations).

  1. Open the Map View.
  2. Expand the left panel and open the Operations tab.
  3. At Operation, select Snap.

Configuring the snap operation

Snap horizon to a trace event
  1. In the navigation bar, select the horizon to snap.
  2. At Volume, select the volume to snap the horizon to.
  3. Event type: choose the waveform to match. From the existing horizon value, find:
    • Nearest Peak: the closest positive peak
    • Nearest Trough: the closest negative trough
    • Nearest Zero (Increasing): the closest zero crossing (from negative to positive).
    • Nearest Zero (Decreasing): the closest zero crossing (from positive to negative).
    • Largest Peak (Window): the most positive (largest) peak in the window
    • Largest Trough (Window): the most negative (deepest) trough in the window
    • Maximum Value (Window): the most positive value (max) in the window
    • Minimum Value (Window): the most negative value (min) in the window
  4. Above (ms) and Below (ms): the window to search, starting from the existing horizon value
  5. At Area, select a polygon/probe to constrain the operation.
  6. Click Snap to start the operation.

Event type examples

Completing the operation

After running the operation:

  • Click Discard to cancel this calculation and delete the results.
  • Click Replace this horizon to converting the picks to the existing horizon.
  • Click Save as New Horizon to create a new horizon.

Note: By default, the new horizon will be named: "horizon_name (snap above value to below value)".  For example, the operation above will yield a new horizon called "Sample (snap -5 ms to +5 ms)". To rename the horizon, see Horizon Details and Configuration.