| Col. | Type | Item | Description | |
|---|---|---|---|---|
| 01 | A1 | Record type identifier | Data record type identifier _: Observation data record | |
| 02 – 07 | A6 | Seismic station code | Six-character JMA code for the seismic station | |
| 08 – 11 | I4 | Seismic station number | Number of the seismic station | |
| 12 | A1 | Blank | Blank | |
| 13 | A1 | Seismometer type | Type of seismometer Blank if the type is unknown. The following letters denote types: A: 87-type electromagnetic strong-motion seismograph (acceleration) B: 87-type electromagnetic strong-motion seismograph (velocity) C: 87-type electromagnetic strong-motion seismograph (displacement) D: 59-type (displacement, including 63-type) E: 61-type (displacement), STS F: Other JMA seismometer (acceleration) G: Other JMA seismometer (velocity) H: Other JMA seismometer (displacement) J: Velocity type, local, buried sensor, with logarithmic amplifier K: Velocity type, local, buried sensor L: Velocity type, local, surface installation M: Velocity type, remote, buried sensor N: Velocity type, remote, surface installation P: JMA OBS (acceleration) Q: JMA OBS (velocity) R: JMA OBS (displacement) S: JMA mechanical strong-motion seismograph T: 67-type velocity sensor with logarithmic amplifier (remote) U: Other JMA seismometer (component unknown) V: JMA installation in volcanic region (acceleration) W: JMA installation in volcanic region (velocity) Y: JMA installation in volcanic region (displacement) Z: JMA strain, etc. a: Displacement (two instances of numerical integration using acceleration seismograph, HPF 1 s) b: Displacement (two instances of numerical integration using acceleration seismograph, HPF 3 s) c: Displacement (two instances of numerical integration using acceleration seismograph, HPF 5 s) d: Displacement (two instances of numerical integration using acceleration seismograph, HPF 10 s) e: Displacement (two instances of numerical integration using acceleration seismograph, HPF 20 s) f: Displacement (two instances of numerical integration using acceleration seismograph, HPF 6 s reproducing mechanical strong-motion seismograph characteristics [S]) j: Displacement (two instances of numerical integration using seismic intensity-meter, HPF 6 s reproducing mechanical strong-motion seismograph characteristics [S]) g: Velocity (numerical integration using acceleration seismograph, HPF 3 s) n: Velocity (numerical integration using acceleration seismograph, HPF 1 s) k: S-net (*), below the sea bed (velocity) l: S-net (*), on the sea bed (velocity) r: Other organization, other OBS (velocity) &: Other organization (acceleration) %: Other organization, surface installation (velocity) s: Other organization, bore-hole installation (velocity) t: Other organization, horizontal-tunnel installation (velocity) #: Other organization (displacement) h: High-sensitivity seismometer with bore-hole installation (velocity) ?: Other organization (component unknown) w: Other organization (broad-band velocity) o: JMA installation in volcanic region, bore-hole installation (velocity) p: JMA installation in volcanic region (broad-band) u: Installation in volcanic region (air vibration) x: Overseas (velocity) | |
| 14 – 15 | I2 | Date | ||
| 16 – 19 | A4 | Phase name | Name of first phase Blank if data are for the third or subsequent phases | |
| 20 – 21 | I2 | Arrival time (hours) | Arrival time of first phase (hours) | |
| 22 – 23 | I2 | Arrival time (minutes) | Arrival time of first phase (minutes) | |
| 24 – 27 | F4.2 | Arrival time (seconds) | Arrival time of first phase (seconds) | |
| 28 – 31 | A4 | Phase name | Name of second or subsequent phase | |
| 32 – 33 | I2 | Arrival time (minutes) | Arrival time of second or subsequent phase (minutes) | |
| 34 – 37 | F4.2 | Arrival time (seconds) | Arrival time of second or subsequent phase (seconds) | |
| 38 – 42 | I5 | Maximum amplitude (ground displacement) | N-S component (X component for S-net (*) stations.) |
Maximum amplitude If the record saturates, "-1" is shown. "-" represents an absence of data. |
| 43 – 45 | F3.1 | Period of maximum amplitude | Period corresponding to maximum amplitude (in seconds) | |
| 46 – 48 | I3 | Time of maximum amplitude occurrence | Time of maximum amplitude occurrence from first phase (seconds) | |
| 49 – 53 | I5 | Maximum amplitude (ground displacement) | E-W component (Y component for S-net (*) stations.) |
Maximum amplitude |
| 54 – 56 | F3.1 | Period of maximum amplitude | Period corresponding to maximum amplitude (in seconds) | |
| 57 – 59 | I3 | Time of maximum amplitude occurrence | Time of maximum amplitude occurrence from first phase (seconds) | |
| 60 – 64 | I5 | Maximum amplitude (ground displacement) | U-D component (Z component for S-net (*) stations.) |
Maximum amplitude |
| 65 – 67 | F3.1 | Period of maximum amplitude | Period corresponding to maximum amplitude (in seconds) | |
| 68 – 70 | I3 | Time of maximum amplitude occurrence | Time of maximum amplitude occurrence from first phase (seconds) | |
| 71 | A1 | Unit of maximum amplitude | J or K: 10−9 m/s; 0.1 microkines 1 or A: 10−8 m/s; microkines 2 or B: 10−6 m; micrometers 3 or C: 10−5 m/s2; mgals 4 or D: 10−7 m/s; 10 microkines 5 or E: 10−5 m; 10 micrometers 6 or F: 10−4 m/s2; 10 mgals 7 or G: 10−6 m/s; 100 microkines 8 or H: 10−4 m; 100 micrometers 9 or I: 10−3 m/s2; 100 mgals J and 1 – 9 are used for magnitude calculations, K and A – I are not used for magnitude calculations. | |
| 72 | A1 | Polarity of initial motion | Polarity of initial motion in N-S component | |
| 73 – 75 | I3 | Amplitude of initial motion | Amplitude of initial motion in N-S component | |
| 76 | A1 | Polarity of initial motion | Polarity of initial motion in E-W component | |
| 77 – 79 | I3 | Amplitude of initial motion | Amplitude of initial motion in E-W component | |
| 80 | A1 | Polarity of initial motion | Polarity of initial motion in U-D component | |
| 81 – 83 | I3 | Amplitude of initial motion | Amplitude of initial motion in U-D component | |
| 84 | A1 | Unit of initial motion amplitude | As per unit of maximum amplitude | |
| 85 – 87 | I3 | Duration | F−P time or total time for which STA or LTA exceeds threshold value (in seconds) | |
| 88 – 89 | I2 | Data year | Last two digits of year | |
| 90 – 91 | I2 | Data month | ||
| 92 | A1 | Data information flags | Flag for first-phase information about filters and realiability. Flag for high reliability A: Auto pick-up phase (from original waveform) B: Auto pick-up phase (HPF 0.5 s) C: Auto pick-up phase (HPF 1.0 s) D: Auto pick-up phase (HPF) X: Auto pick-up phase (BPF 0.1 – 0.2 s) E: Auto pick-up phase (BPF 0.1 – 0.5 s) F: Auto pick-up phase (BPF 0.1 – 1.0 s) W: Auto pick-up phase (BPF 0.2 – 0.5 s) G: Auto pick-up phase (BPF) H: Auto pick-up phase (LPF 0.1 s) I: Auto pick-up phase (LPF 0.2 s) J: Auto pick-up phase (LPF) L: Auto pick-up phase (other) M: Manual pick-up phase (from original waveform) N: Manual pick-up phase (HPF 0.5 s) O: Manual pick-up phase (HPF 1.0 s) P: Manual pick-up phase (HPF 0.3 s) Q: Manual pick-up phase (BPF 0.1 – 0.5 s) R: Manual pick-up phase (BPF 0.1 – 1.0 s) S: Manual pick-up phase (BPF 0.3 – 0.5 s) T: Manual pick-up phase (LPF 0.1 s) U: Manual pick-up phase (LPF 0.2 s) V: Manual pick-up phase (LPF) Z: Manual pick-up phase (other) Flag for low reliability a: Auto pick-up phase (from original waveform) b: Auto pick-up phase (HPF 0.5 s) c: Auto pick-up phase (HPF 1.0 s) d: Auto pick-up phase (HPF) x: Auto pick-up phase (BPF 0.1 – 0.2 s) e: Auto pick-up phase (BPF 0.1 – 0.5 s) f: Auto pick-up phase (BPF 0.1 – 1.0 s) w: Auto pick-up phase (BPF 0.2 – 0.5 s) g: Auto pick-up phase (BPF) h: Auto pick-up phase (LPF 0.1 s) i: Auto pick-up phase (LPF 0.2 s) j: Auto pick-up phase (LPF) l: Auto pick-up phase (other) m: Manual pick-up phase (from original waveform) n: Manual pick-up phase (HPF 0.5 s) o: Manual pick-up phase (HPF 1.0 s) p: Manual pick-up phase (HPF 0.3 s) q: Manual pick-up phase (BPF 0.1 – 0.5 s) r: Manual pick-up phase (BPF 0.1 – 1.0 s) s: Manual pick-up phase (BPF 0.3 – 0.5 s) t: Manual pick-up phase (LPF 0.1 s) u: Manual pick-up phase (LPF 0.2 s) v: Manual pick-up phase (LPF) z: Manual pick-up phase (other) | |
| 93 | A1 | Data information flag | Flag for second-phase information about filters and realiability. | |
| 94 | A1 | Data information flag | Flag for maximum-amplitude information P: Use of horizontal amplitudes for magnitude calculation regardless of their periods | |
| 95 | A1 | Data information flag | Flag for other data F: Added or modified after making provisional data G: Added or modified after making definite data R: Added for reference | |
| 96 | A1 | Data weight | Data weight for calculation of hypocenter location 0: Not used for calculation of hypocenter location | |
(*) S-net: Seafloor observation network for earthquakes and tsunamis along the Japan Trench