October 8, 2023 Earthquake: Izu Islands, Japan
A magnitude 4.9 earthquake struck Izu Islands, Japan on October 8, 2023 at 20:25:23 UTC, 10 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
- October 8, 2023
- Time
- 20:25:23 UTC
- Place
- Izu Islands, Japan
- Magnitude
- 4.9 (mb)
- Focal depth
- 10 km (6 mi)
- Tsunami
- Yes: the tsunami it caused
- Volcano
- The eruption it came with
- Epicenter
- 29.707° N, 139.902° E
- Country
- Japan
- Region
- East Asia
- USGS record
- The USGS’s page for this 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.
A tsunami was generated with the following recorded wave heights in centimeters: 30 on Hachijo Jima; 25 on Kozu Shima and Miyake Jima; 20 at Tosa-shimizu Shi; 15 at Mera; 12 at Kushimoto; 10 on Chichi Jima, at Kure and at Okada; 5 at Muroto-misakicho.
From the USGS event page for us6000le2t. 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 |
|---|---|---|---|
| 4.7 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.078 · 16 stations |
| 5.0 | ML, local (Richter) | NOAA National Tsunami Warning Center | Reviewed · 6 stations |
| 5.0 | Mi | NOAA Pacific Tsunami Warning Center | Reviewed · 1 stations |
Sources NCEI cites
The publications NCEI lists for this record. The numbers match the “reference #” notes in its account above.
- #13456 U.S. Geological Survey (2017 to present). Earthquake Hazards Program, Advanced National Seismic System (ANSS) Comprehensive Catalog of Earthquake Events and Products.
Other significant earthquakes nearby
Within 200 km, the deadliest first.
More
Significant earthquakes of 2023The 2000sEvery quake the USGS located in 2023Recent 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 10709. The written accounts and the magnitude estimates are from the USGS earthquake catalog, event us6000le2t, matched to this record by time, place and magnitude.