All earthquakes
1.3
very light
EARTHQUAKE DETAILS

17 km West of Acceglio

128 months ago · 20 Feb, 07:31

A very light earthquake, probably not felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 55% of Italian events in the past year

Where

17 km West of AcceglioEarthquakes in the province of CuneoEarthquakes in Piemonte

How far away could it be felt?

A quake this small is usually not felt by people: only seismographs record it.

Statistical estimate from the Italian intensity attenuation model (INGV): actual perception depends on geology, buildings and depth. Very shallow events can be felt locally even below the threshold.

Earthquake map

8 events
Magnitude:lightweakmoderatestrong

The energy released

How much energy this quake unleashed, translated into everyday comparisons.

1.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×355 its energy
M0this quakeM2

Each extra magnitude unit releases about 32 times more energy: an M5 is not "a bit stronger" than an M4 — it is a different league.

Energy estimated with the standard Gutenberg–Richter relation; an average lightning bolt ≈ 1 billion joules. Indicative values.

The race of the seismic waves

Two waves set off from the hypocentre: the faster P wave arrives first with a sharp jolt; the S wave carries the actual shaking.

P waves — the first sharp jolt (~6 km/s)S waves — the strongest shaking (~3.5 km/s)
t ≈ 31 s

Animation sped up ~6× compared to reality.

  • Cuneo
    64 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Moncalieri
    93 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Torino
    102 km from the epicentre
    first tremor in ~17 s
    main shaking in ~29 s
  • Sanremo
    109 km from the epicentre
    first tremor in ~18 s
    main shaking in ~31 s

Theoretical times with average crustal speeds: real values vary with geology. The gap between P and S waves is what earthquake early-warning systems rely on.

How deep it was born

8 km
shallow

At only a few km deep the shaking is felt more sharply at the surface.

in line with the area average (~11 km)

For the same magnitude, a shallow earthquake is felt much more than a deep one: the energy starts closer to the surface.

What kind of quake is this?

Foreshock

In hindsight it was a foreshock: 128 months ago the same area had a stronger quake (M1.7). This can only be said after the fact — it was not predictable beforehand.

1.7
The mainshock
17 km West of Acceglio
128 months ago · 24 Feb, 21:12
Activity in the area right now (30 km radius)
1
last 24 hours
4
last 7 days
10
last 30 days
1 before6 after
this quake
Strongest of the sequence1.7

How often does it happen here?

about every ~16 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 266 events in the last 12 years of the INGV catalogue.

An average computed on the recent past: it tells how used this area is to shaking, not when the next quake will come — earthquakes cannot be predicted.

The great earthquakes in this area's history

Almost a thousand years of catalogues: the strongest documented events within ~50 km.

19595.4
Ubaye earthquake
5 April 1959 · 4 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19355.3
Embrunais earthquake
19 March 1935 · 22 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19045.1
Briançonnais earthquake
12 July 1904 · 49 km from here
VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
19385.1
Queyras earthquake
18 July 1938 · 19 km from here
VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.

Source: Parametric Catalogue of Italian Earthquakes CPTI15 (INGV, CC BY 4.0).

The closest seismic structure

Brianconnais

The epicentre lies about 5 km from Brianconnais, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.2between 5 and 20 km deep

Faults are mapped to build better and understand the territory: knowing them says nothing about when an earthquake will occur, which remains unpredictable. Source: DISS 3.3 (INGV, CC BY 4.0).

Other quakes in the area

1.5
17 km West of Acceglio
1 km North-East · 8 km
128 months ago
18 Feb, 20:03
1.2
6 km North-West of Argentera
15 km South-East · 10 km
128 months ago
24 Feb, 02:14
1.7
17 km West of Acceglio
0 km South · 10 km
128 months ago
24 Feb, 21:12
1.7
1 km North of Bellino
22 km North-East · 10 km
127 months ago
11 Mar, 22:41
1.2
13 km West of Pontechianale
26 km North-East · 7 km
127 months ago
14 Mar, 22:12
1.1
France
27 km South-West · 11 km
127 months ago
18 Mar, 21:43
1.4
14 km West of Argentera
19 km South · 18 km
127 months ago
20 Mar, 18:11

Data: INGV — National Institute of Geophysics and Volcanology (CC-BY 4.0)

Estimates computed by Meteare on INGV data (Gutenberg–Richter relation; Italian macroseismic intensity attenuation model).

We use cookies to analyse site traffic and improve your experience.

Privacy PolicyCookie Policy