Reviewed by USGSRussia105y ago
M7.3 earthquake 77 km ESE of Mil’kovo, Russia
Saturday, February 3, 1923, 18:42:58 UTC · 54.354°N, 159.656°E
A magnitude 7.3 earthquake struck 77 km ESE of Mil’kovo, Russia on Saturday, February 3, 1923, 18:42:58 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M8.4 on February 3, 1923.
- Magnitude
- 7.3
- Major · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search area
In context
How big was it, and why here?
Energy released
1.3 megatons of TNT
That is about 89 times the Hiroshima bomb. It released about 2,818 times the energy of a magnitude 5.0.
Tectonic setting
219 km
from the nearest mapped plate boundary, between the Okhotsk and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
15 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 200 km
USGS lists 3 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.5 on February 12, 1923. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 22 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.41923 Kamchatka, Russia EarthquakeFebruary 3, 1923 · 55 km E of this epicenter
- 8.043 km E of Ust’-Kamchatsk Staryy, RussiaJanuary 30, 1917 · 300 km NE of this epicenter
- 7.7115 km ESE of Petropavlovsk-Kamchatsky, RussiaJune 25, 1904 · 182 km S of this epicenter
- 7.495 km NNE of Ozernovskiy, RussiaMay 4, 1911 · 286 km SW of this epicenter
- 7.3233 km SE of Atlasovo, RussiaJuly 31, 1915 · 162 km E of this epicenter
- 7.3163 km ENE of Petropavlovsk-Kamchatsky, RussiaFebruary 2, 1923 · 102 km SE of this epicenter
- 7.297 km NNE of Ozernovskiy, RussiaAugust 17, 1907 · 293 km SW of this epicenter
- 7.2143 km E of Petropavlovsk-Kamchatsky, RussiaJune 27, 1904 · 135 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 21 recorded deaths. The most severe:
- 1923M7.2
Near Kamchatka
13 Apr 1923 · 299 km away · intensity X
18 deathsSevere damage ($5–24M)tsunami
- 1923M8.4
Kamchatka
3 Feb 1923 · 55 km away · intensity XI
3 deaths$2 million damagetsunami
- 1841M8.4
Off Kamchatka
17 May 1841 · 284 km away · intensity XI
Moderate damage ($1–5M)tsunami
- 1904M8.3
Off Kamchatka
25 Jun 1904 · 265 km away · intensity X
Limited damage (under $1M)tsunami
- 1904M8.1
Off Kamchatka
25 Jun 1904 · 265 km away · intensity X
Limited damage (under $1M)tsunami
- 1923M7.7
Kamchatka Peninsula
24 Feb 1923 · 190 km away
Limited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.