Review automatic origins

1. Open scolv or goto scolv.
2. Read the events from database including the interesting event (if necessary, because scolv was not running).
3. Doubleclick on the event in “Events” tab.
4. Check distribution of the arrival residuals in the residualplot of the “Location” tab. There should be no large outliers or a trend that indicates a wrong depth.
5. Check the overall “RMS Res.” of the event. This should be smaller than 2.5.
6. Press “Show waveforms” to open the ManualPicker with the according waveforms.
7. Press “Align by P-arrival” in the ManualPicker.
8. Adjust the zoomed trace to the phase onset.
9. Activate P picking mode. Only first P arrivals should be picked.
10. Choose a filter for the waveform.
11. Pick clear phases and deactivate bad traces.
12. Activate S picking mode.
13. Change component to N or E for S for picking S-phases.
14. Pick up only clear S-phases. Note, S-phases can cause large residual even if the the onset is very clear because the velocity model for S waves is more uncertain.
15. Press the relocate button in the ManualPicker.
16. Revise the location results by repeating steps 4 + 5.
17. Exclude outliers in arrival residual plot or verify the picks.
18. Relocate and check depth. If necessary fix the depth and relocate again.
19. Press “Compute magnitudes”.
20. Press “ok”. In case not all magnitude calculations are finished you can either take the available ones or wait until magnitude calculation is finished.
21. Goto “Magnitudes” tab.
22. Check distribution of station magnitudes.
23. Exclude outliers.
24. Press “Recalculate”.
25. Repeat steps 22 -24 for all different magnitude types.
26. Goto “Location” tab and press “Commit” to send the solution to the messaging system.

Manual event detection and localisation

1. Watch for blinking triangles or changing ground motion in scmv.
2. If only one or two triangles are blinking check the waveforms in the station info window in scmv.
3. In case that more triangles are blinking goto scrttv.
4. Check the waveforms in scrttv and search for typical earthquake signals.
5. Identify the trace with the first arrival which should be the station closest to the earthquake location.
6. Create a preliminary origin by clicking on the trace of the closest station with the middle mouse button. Place the cursor some minutes before the pick or the onset in the trace to start the time window for the waveforms before the estimated source time.
7. Goto to the scolv and press show waveforms
8. Pick more than 5 P-phases, take only clear arrivals. Note that the theoretical arrivals are not reliable because the origin time and location is only a rough estimate.
9. Press locate. Now the theoretical arrivals are reliable.
10. Pick more P-phases (minimum 6-8 P-phases). Always try the different filters to find the best signal to noise ratio for the data.
11. Press locate.
12. Goto the “Location” tab of scolv and check the residuals. They should have no trend with distance but should be regularly distributed around the center line. A positive trend indicates your location is too deep. A negative trend indicates your location is to shallow.
13. Commit the origin.
14. To involve more fitting automatic picks press “Show details” in scesv. Otherwise, the automatic picks are not included to the manual solution.
15. Go back to the scolv and press “Import Picks”.
16. Check the waveforms again and pick more P- and S-phases if possible. Only use very clear S-Phases for a fast location, you can review the data later on again. Note, S-phases can cause large residual even if the the onset is very clear because the velocity model for S waves is more uncertain.
17. Locate again and check the residuals. In case they are ok, commit the origin again.
18. You can repeat steps 13-16 several times to get all incoming phases.
19. Commit the origin again.