EHB Bulletin: csv arrivals output
The CSV output for the Arrivals search produces one line per arrival. Click here to load an example.
Each line has 25 fields, which are preformatted and comma separated. Each field is in one of 4 groups:
EVENT, ARRIVAL DATA, ORIGIN DATA, EVENT MAGNITUDE
| Group | Title | Position | Description |
|---|---|---|---|
EVENT | EVENTID | 1-9 | Unique id number specific to each EHB event. |
ARRIVAL DATA | REPORTER | 11-19 | Name of the agency that reported the arrival data. |
ARRIVAL DATA | STA | 21-25 | Station name where the arrival was recorded. |
ARRIVAL DATA | LAT | 27-34 | Latitude of station. |
ARRIVAL DATA | LON | 36-44 | Longitude of station. |
ARRIVAL DATA | ELEV | 46-42 | Elevation of station (m). |
ARRIVAL DATA | CHN | 44-46 | Channel the arrival was recorded on (e.g. SHZ, BHZ, BHE, etc.). |
ARRIVAL DATA | DIST | 48-51 | Epicentral distance (degrees) from the station to the epicentre of the prime origin. |
ARRIVAL DATA | BAZ | 53-57 | Back-azimuth - azimuth from the station to the epicentre of the prime origin. |
ARRIVAL DATA | PHASE | 59-66 | Phase name of the arrival determined by the EHB. |
ARRIVAL DATA | DATE | 68-77 | Date of the arrival. |
ARRIVAL DATA | TIME | 79-89 | Time of the arrival. |
ARRIVAL DATA | RES | 91-95 | Travel-time residual for PHASE. This is computed using the ak135 velocity model. |
ARRIVAL DATA | TDEF | 97-100 | Time-defining flag. Set to true if the arrival-time was used in the computation of the prime hypocentre. This is generally only known for ISC computed hypocentres. |
ARRIVAL DATA | AMPLITUDE | 102-110 | Amplitude measurement (nm). |
ARRIVAL DATA | PER | 112-116 | Period (s) used in the amplitude measurement. |
ORIGIN DATA | AUTHOR | 118-126 | Author of the prime hypocentre. |
ORIGIN DATA | DATE | 128-137 | Date of the prime hypocentre. |
ORIGIN DATA | TIME | 139-149 | Time of the prime hypocentre. |
ORIGIN DATA | LAT | 151-158 | Latitude of the prime hypocentre. |
ORIGIN DATA | LON | 161-169 | Longitude of the prime hypocentre. |
ORIGIN DATA | DEPTH | 171-175 | Depth (km) of the prime hypocentre. |
EVENT MAGNITUDE | AUTHOR | 177-185 | Author of the selected magnitude. |
EVENT MAGNITUDE | TYPE | 187-192 | Magnitude type (e.g. Mw, MS, mb, ml, etc. ) of the selected event magnitude. |
EVENT MAGNITUDE | MAG | 194-197 | Magnitude value of the selected event magnitude. |
Notes on the event magnitude
As there are potentially many magnitudes for each event, to reduce the size of the output, only a single magnitude is returned per event for the arrival search. To determine the magnitude that is selected, the following logic is used:
- If no author is specified, choose a magnitude associated to the prime hypocentre.
- If there is more than one magnitude associated to the prime hypocentre, preferentially choose Mw, mb, ms, ml, respectively.
- Preferentially choose the largest value if any choice remains.
- If no author is specified and there is no magnitude associated to the prime hypocentre, preferentially choose magnitudes by GCMT/HRVD, NEIC, NIED, JMA, IDC (mb only).
- If there is more than one magnitude associated to the preferred author, preferentially choose Mw, mb, ms, ml, respectively.
- Preferentially choose the largest value if any choice remains.
- If no author is specified and there is no magnitude associated with the prime hypocentre, and there is no magnitude by one of the preferred magnitude authors, preferentially choose Mw, mb, ms, ml, respectively.
- Choose the largest value if any choice remains.
