June 13, 1984 Earthquake: Tori Shima, Okinawa, Japan
A magnitude 5.5 earthquake struck Tori Shima, Okinawa, Japan on June 13, 1984 at 02:29:25 UTC, 41 km below the surface. It caused a tsunami.
Map
Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.
The earthquake
- Date
- June 13, 1984
- Time
- 02:29:25 UTC
- Place
- Tori Shima, Okinawa, Japan
- Magnitude
- 5.5 (Ms)
- Magnitude scales
- Ms 5.5 · mb 5.5
- Focal depth
- 41 km (25 mi)
- Tsunami
- Yes: the tsunami it caused
- Volcano
- The eruption it came with
- Epicenter
- 31.448° N, 140.036° E
- Country
- Japan
- Region
- East Asia
- USGS record
- The USGS’s page for this earthquake
Ms: surface-wave magnitude. mb: body-wave (P-wave) magnitude. NCEI’s headline magnitude is the best of these for the earthquake.
The toll
The record gives no deaths, injuries or damage for this earthquake.
What happened
The USGS’s account of the effects of this earthquake.
Felt (I JMA) at Yokohama. Six centimeters tsunami on Hachijo-jima. CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 15S, 28C Centroid Location: Origin Time 02:29:28.5 0.2 Lat 31.39N 0.03 Lon 139.93E 0.04 Dep 15.2 1.7 Half-duration 2.5 Moment Tensor; Scale 10**24 D-CM Mrr=4.01 0.10 Mtt=-2.21 0.09 Mff=-1.80 0.14 Mrt=-0.13 0.35 Mrf=-0.29 0.30 Mtf=-0.64 0.10 Principal Axes: (T) Val=4.02 Plg=87 Azm=108 (N) Val=-1.34 Plg=2 Azm=234 (P) Val=-2.69 Plg=2 Azm=324 Best Double Couple:Mo=3.4*10**24 NP1:Strike=55 Dip=43 Slip=92 NP2:Strike=232 Dip=47 Slip=88
From the USGS event page for usp00024zq. U.S. Geological Survey text and figures are in the public domain.
Magnitude estimates
The magnitudes the USGS catalog lists for this earthquake, by scale and by who computed them. NCEI’s own scales are in the table above.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 5.7 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 5.62 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.6 | Mwc, centroid moment | Global CMT project | Preliminary |
What the record says
NCEI’s account, from the sources it cites.
June 13, 1984, 02:29:25.3 UTC, South of Honshu, japan, 31.448 N, 140.036 E, depth 41 km, magnitude 5.5 mb, 5.5 MS. Felt (I JMA) at Yokohama. Six-cm tsunami on Hachijo-jima. (reference #1053)
Sources NCEI cites
The publications NCEI lists for this record. The numbers match the “reference #” notes in its account above.
- #1053 National Earthquake Information Center (NEIC) (1971 to 2013). Preliminary Determination of Epicenters (PDE), a weekly and monthly publication, National Earthquake Information Center, U.S. Geological Survey, Golden, Colorado, 1971 to 2013.
Other significant earthquakes nearby
Within 200 km, the deadliest first.
- January 1, 2006, S. of, Honshu, Japan
- September 23, 2024, Izu Islands, Japan
- May 6, 2018, S. of, Honshu, Japan
- September 4, 1996, Honshu Island, Japan
- May 2, 2015, S. of, Honshu, Japan
- October 6, 2023, Izu Islands, Japan
- October 5, 2023, Izu Islands, Japan
- September 30, 1997, S, Honshu, Japan
- August 11, 1992, S, Honshu, Japan
- October 8, 2023, Izu Islands, Japan
- April 21, 1916, Off East Coast Honshu, Japan
More
Significant earthquakes of 1984The 1900sEvery quake the USGS located in 1984Recent earthquakes near hereThis day in weather history
Sources
Significant earthquakes from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-10-01. NCEI earthquake 6652. The written accounts and the magnitude estimates are from the USGS earthquake catalog, event usp00024zq, matched to this record by time, place and magnitude.