8.6 Registering new events into SEISAN

Mulplt is the main tool for checking and putting new events into SEISAN. New events with waveform data can appear in two ways in SEISAN:

  1. Unprocessed waveform files are available in a work directory and have to be inspected and possibly put into the database. No S-files have been made.
  2. Raw data has already been put into a SEISAN database with S-files and corresponding waveform files in some work directory, the data has not been checked. This process has most likely been done with the automatic data collection software SEISNET (Ottemöller and Havskov, 1999), or other similar programs like RTQUAKE (similar to SeisComP and and SC2SEI (gets data form SeisComP), see ftp://ftp.geo.uib.no/pub/seismo/SOFTWARE/. However, events can also have been auto registered with program AUTOREG.
  3. Registering from continuous data: SEISAN continuous data base, BUD or SeisComp archives or a large SEED file.

In both cases above, the aim is to inspect an event and decide if the event is real and should be put into the database using option `p'. All work must be done from the directory where the raw waveform files are located. The process of putting an event into the database results in creating the S-file (option1), giving the event identifiers and copying the waveform files of registered events to the waveform directory.By pushing p(Regis), the user will be prompted for distance indicator, which has to be L, R or D for local, regional or distant event. It is possible here to enter 2 characters like LE or LV for local explosion or local volcanic event. The event type or event ID can be any character. Four characters are predefined and should only be used if the following definition correspond: P(probable explosion), E(explosion), Q(confirmed earthquake) or V(Volcanic event). If the user enter L, R or D in lower case, the case will automatically be changed to upper case. The same also happends with E, P, Q and V. A third cahracter can optionally be entered for the model indcator which is put into column 21 of the header line. The volcanic events have a sub classification which can be entered when registering an event as volcanic, see section 39. The process of registering the event into the database implies that a new S-file is created or registered and in the S-file. An operator ID will be asked and the operator ID will be put on the ID-line. The question about operator will only be asked for the first event since it is assumed that all subsequent events are put into the same database by the same operator. The event ID, can later be used with the SELECT program to select out particular event types. When first putting an event into the database, the user is also prompted for database.

Option (1)
Data is available as waveform files only and a list of files must be made first with DIRF. Main option 0, 1 or 2 can be used for plotting. The `p' option creates the S-file and copies the waveform file to the WAV directory. The waveform file remains in the working directory. Unwanted waveform files can also be deleted so that when all events have been put in, only waveform files of `real' events remain in working directory. These can then be plotted with one run of MULPLT, see section 8.1.

Option (2)
Data is available already in a database, however since the data has not been inspected, the waveform files are still in a work directory. In EEV, the first unprocessed event in the month is found with command `ss' and MULPLT is started with command `po' to invoke all defaults. If the event is to remain in the database, it must be registered with option `p'. The process and the questions are the same as in option (1) except that the S-file is not created since it is already there. The S-file is cleaned for all processing information from SEISNET if present. This normally also includes automatic phase picks. However, they can be kept if parameter REG_KEEP_AUTO is set in the SEISAN.DEF file. The status of the files also changes to being newly registered as under option (1) (see definition of processing codes in Appendix 1) and waveform file(s) copied to WAV. Before registering, it might be an advantage to merge waveform files and delete unwanted files (could be false triggers), see section 8.5. Files can only be merged and deleted in working directory with commands Delw and Merge (Menu). Delw command only deletes the waveform file names in the S-file. In this process of putting new events into the database, it is also an advantage to delete unwanted events. This is done with option `S'(Del S)'. The S-file is deleted, but the waveform files remain in the working directory.

Option (3)

When reading continuous data, an output file can be made with the Out option and that output file can be registered. However, it is also possible to do this in a single operation using the Register option like above. The selected time window is then extracted, the waveform file copied to WAV and the S-file registration made. In addition to the questions above, additional questions are given:

Output channels on screen: s

No output, just register: n

No output, jusr ARC line: a

Output all channels: enter

These option are intended to be used with routine operation when many channels are present and the user only view a few, like all vertical channels, but want to extract (and register a file with all channels). For ARC archive, the user might want to work directly with the archive from EEV and thus not extract out a waveform file but only create a reference to the archive.

Preprocessing of data while registering new events, option (1)

Normally a series of events are registered first and MULPLT terminated. Then EEV or SE is started up for interactive picking and location. However, if preliminary processing is desired while registering the event, this is also possible.

Phase picks: If phases are picked before the event is registered, these readings are saved in the database at the time of registration. After the event has been registered, MULPLT automatically goes to the next event in FILENR.LIS and no more phase picking can be done.

Processing with a given program: Optionally MULPLT can, after registration, start any program processing the newly registered event. E.g. the AUTOPIC program can be started or a program reading amplitudes etc. The program name is defined in MULPLT.DEF.

Locating the event: As the final step after registration, the event can optionally be located and the location optionally placed in the database.

The above options have been put in on the suggestion of Brian Baptie, who is using it for rapid processing of volcanic events, where in most cases the operator only wants to look at the event once.