Reviewed by USGSItaly111y ago
M5.7 earthquake 6 km SW of Monterchi, Italy
Thursday, April 26, 1917, 09:36:03 UTC · 43.453°N, 12.046°E
A magnitude 5.7 earthquake struck 6 km SW of Monterchi, Italy on Thursday, April 26, 1917, 09:36:03 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M6.0 on August 16, 1916.
- Magnitude
- 5.7
- Moderate · mw
- Depth
- 10 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 earthquake
In context
How big was it, and why here?
Energy released
6 kilotons of TNT
That is about 1/3 of the Hiroshima bomb. It released about 12 times the energy of a magnitude 5.0.
Tectonic setting
488 km
from the nearest mapped plate boundary, between the Eurasian and African plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
10 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 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 19 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.74 km WNW of San Benedetto dei Marsi, ItalyJanuary 13, 1915 · 202 km SE of this epicenter
- 6.019 km NNE of Gabicce Mare, ItalyMay 17, 1916 · 98 km NE of this epicenter
- 6.015 km NNE of Pesaro, ItalyAugust 16, 1916 · 101 km NE of this epicenter
- 5.97 km NE of Novi Vinodolski, CroatiaMarch 12, 1916 · 295 km NE of this epicenter
- 5.815 km WNW of Perušić, CroatiaJuly 14, 1916 · 288 km NE of this epicenter
- 5.67 km NW of Marliana, ItalyOctober 27, 1914 · 123 km NW of this epicenter
- 5.645 km NE of Ponte Sasso, ItalyAugust 16, 1916 · 134 km NE of this epicenter
- 5.51 km WNW of Forlì, ItalyFebruary 19, 1911 · 86 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 52 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 82,061 recorded deaths. The most severe:
- 1703
Central Apennino, Norcia, L'Aquila, Perugia
14 Jan 1703 · 114 km away · intensity XI
40,000 deathsExtreme damage ($25M+)
- 1915M7.5
Marsica, Avezzano, Abruzzi
13 Jan 1915 · 201 km away · intensity XI
29,978 deaths$60 million damage
- 1703M6.7
L'Aquila (Aquila)
2 Feb 1703 · 144 km away · intensity XI
10,000 deathsSevere damage ($5–24M)tsunami
- 1706
Sulmona To Campobasso, Abruzzi
3 Nov 1706 · 294 km away · intensity X
1,000 deathsSevere damage ($5–24M)
- 1789
Citta Di Castello,Sansepolcro
30 Sep 1789 · 13 km away · intensity X
500 deathsSevere damage ($5–24M)
- 1730
Norcia
12 May 1730 · 106 km away · intensity X
200 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.