| Col. | Type | Item | Description |
|---|---|---|---|
| 01 | A1 | Record type identifier | Agency codes: J: Hypocenter record determined by JMA U: Hypocenter record determined by USGS I: Hypocenter record determined by other international organizations (ISC, IASPEI, etc.) |
| 02 – 05 | I4 | Year | Year of origin time (Japan Standard Time = UTC + 9 h; the same applies below.) |
| 06 – 07 | I2 | Month | Month of origin time |
| 08 – 09 | I2 | Day | Day of origin time |
| 10 – 11 | I2 | Hour | Hour of origin time |
| 12 – 13 | I2 | Minute | Minute of origin time |
| 14 – 17 | F4.2 | Second | Second of origin time blank after the decimal point in case of fixed hypocenter |
| 18 – 21 | F4.2 | Standard error (seconds) | Standard error for origin time (seconds) Blank when hypocenter is fixed, or when hypocenter of template event is adopted in the Matched filter method. |
| 22 – 24 | I3 | Latitude (degrees) | Latitude of hypocenter (degrees) |
| 25 – 28 | F4.2 | Latitude (minutes) | Latitude of hypocenter (minutes) blank after the decimal point in case of fixed hypocenter |
| 29 – 32 | F4.2 | Standard error (minutes) | Standard error for latitude (minutes) Blank when hypocenter is fixed, or when hypocenter of template event is adopted in the Matched filter method. |
| 33 – 36 | I4 | Longitude (degrees) | Longitude of hypocenter (degrees) |
| 37 – 40 | F4.2 | Longitude (minutes) | Longitude of hypocenter (minutes) blank after the decimal point in case of fixed hypocenter |
| 41 – 44 | F4.2 | Standard error (minutes) | Standard error for longitude (minutes) Blank when hypocenter is fixed, or when hypocenter of template event is adopted in the Matched filter method. |
| 45 – 49 | F5.2 | Depth (kilometers) | Depth in kilometers (depth-free method) The depth of focus is treated as an unknown variable. |
| I3, 2X | Depth in kilometers (depth-slice method) The optimal solution is sought with different source depths. Width of change: 10 km (1926 – 1960, 1967 – 1982) Width of change: 20 km (1961 – 1966) Width of change: 1 km (1983 – ) Hypocenters from before 1982 are being re-examined and relocated based on calculation using the depth-free method or the 1 km-width depth-slice method. | ||
| 50 – 52 | F3.2 | Standard error (kilometers) | Standard error for depth (kilometers) Blank when depth is determined using the depth-slice method, or when hypocenter of template event is adopted in the Matched filter method. |
| 53 – 54 | F2.1 | Magnitude 1 | See magnitude type 1 When the magnitude is less than 0, this column is denoted as follows: -0.1: -1 -0.9: -9 -1.0: A0 -1.9: A9 -2.0: B0 -3.0: C0 |
| 55 | A1 | Magnitude type 1 | JMA magnitudes J: MJ — Local Meteorological Office magnitude D: MD — Displacement magnitude d: As per MD, but for two stations V: MV — Velocity magnitude v: As per MV, but for two or three stations |
| Moment magnitudes W: MW — When the Agency Code is J, moment magnitude is based on JMA's centroid moment tensor solution. Otherwise, moment magnitude is determined by JMA or another organization such as USGS. | |||
| Other organizations' magnitudes B: mb — USGS body wave magnitude S: MS — USGS surface wave magnitude | |||
| blank: Undetermined | |||
| 56 – 57 | F2.1 | Magnitude 2 | See magnitude 1 |
| 58 | A1 | Magnitude type 2 | See magnitude type 1 |
| 59 | A1 | Travel time table | Type of travel time table
1: Reported by Ichikawa and Mochizuki (1971), Hamada (1984) (hereafter 83A) and others 2: Reported by Ichikawa (1978) (hereafter LL) (for the area far east of the Sanriku district) 3: Tables reported by Ichikawa and Mochizuki (1971) and LL, or 83A and LL (for the area east of Hokkaido) 4: Tables reported by Ichikawa and Mochizuki (1971) and LL, or 83A and LL (for southern parts of the Kurile Islands） 5: Table reported by Ueno et al. (2002) (hereafter JMA2001) 6: JMA2001 and LL (with the mesh interval of LL matched to that of JMA2001) (for southern parts of the Kurile Islands) 7: JMA2001A for inland stations, JMA2020A for those within landward slopes, JMA2020B for those in outer-rise regions of the Japan Trench, and JMA2020C for those within the Nankai Trough area Blank: Determined by other agencies The tables are used when a hypocenter is determined in these areas: 2: Far east of Sanriku 3: East of Hokkaido 4 or 6: Southern parts of the Kurile Islands 7: Tables corresponding to individual station locations used in hypocenter calculation |
| 60 | A1 | Hypocenter location precision | Hypocenter location precision 1: Depth-free method 2: Depth-slice method 3: Fixed depth 4: Based on depth phase 5: Based on S−P time 7: Poor solution (before March 2016) 8: Undetermined or not accepted 9: Hypocenter fixed (of which the most close station) M: Matched filter method |
| 61 | A1 | Subsidiary information | Subsidiary information on event 1: Natural earthquake 2: Insufficient number of JMA stations 3: Artificial event 4: Eruption earthquake and others 5: Low-frequency earthquake |
| 62 | A1 | Maximum intensity | 1: One 2: Two 3: Three 4: Four 5: Five (until September 1996) 6: Six (until September 1996) 7: Seven A: Five lower B: Five upper C: Six lower D: Six upper R: Remarkable earthquake (shock felt over 300 km away) (until 1977) M: Moderate earthquake (shock felt over 200 km away but not over 300 km away) (until 1977) S: Small earthquake (shock felt over 100 km away but not over 200 km away) (until 1977) L: Local earthquake (shock felt less than 100 km away) (until 1977) F: Felt earthquake (until 1984) X: Shock felt by some people but not by JMA observers (until September 1996) |
| 63 | A1 | Damage class | Damage class (after Utsu) 1: Slight damage (cracks on walls and ground) 2: Light damage (damage to houses, roads, etc.) 3: 2 – 19 fatalities or 2 – 999 houses destroyed 4: 20 – 199 fatalities or 1,000 – 9,999 houses destroyed 5: 200 – 1,999 fatalities or 10,000 – 99,999 houses destroyed 6: 2,000 – 19,999 fatalities or 100,000 – 999,999 houses destroyed 7: 20,000+ fatalities or 1,000,000+ houses destroyed X: Injury or damage of unclear scale (until 1988) Y: Injury and damage included in the grade for the preceding or following event (until 1988) |
| 64 | A1 | Tsunami class | 1929 – 1988 Tsunami class (after Utsu) 1: Tsunami recorded by tidal gage but no damage caused T: Tsunami generated |
| 1989 – Tsunami class (after Imamura and Iida, 1958) Height/damage 1: 50 cm/none 2: 1 m/very slight damage 3: 2 m/slight damage to coastal areas and vessels 4: 4 – 6 m/human injury 5: 10 – 20 m/damage along more than 400 km of coastline 6: 30 m+/damage along more than 500 km of coastline | |||
| 65 | I1 | District number | Number of epicenter location district based on Appendix 1.A.3 Geographical region names |
| 66 – 68 | I3 | Region number | Number of epicenter location region |
| 69 – 92 | A24 | Region name | Name of epicenter location region |
| 93 – 95 | I3 | Number of stations | Number of stations contributing to hypocenter determination |
| 96 | A1 | Hypocenter determination flag | K: High-precision hypocenters (Manual, closely examined) S: Low-precision hypocenters (Manual, closely examined) k: Middle-precision hypocenters (Manual) s: Low-precision hypocenters (Manual) A: Middle-precision hypocenters (Auto) a: Low-precision hypocenters (Auto) N: Undetermined or not accepted or fixed hypocenters F: Far field |