All earthquakes
0.9
very light
EARTHQUAKE DETAILS

M0.9 earthquake · 1 km South of Serravalle Langhe (CN)

8 years ago · 19 Feb 2018, 19:28

A very light earthquake, probably not felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 23% of Italian events in the past year

Where

1 km South of Serravalle LangheEarthquakes 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

6 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,413 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 ≈ 16 s

Animation sped up ~3× compared to reality.

  • Asti
    41 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Savona
    42 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Cuneo
    44 km from the epicentre
    first tremor in ~8 s
    main shaking in ~13 s
  • Moncalieri
    54 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 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

11 km
medium depth
1.2 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

in line with the area average (~10 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?

Aftershock

It is an aftershock: it follows a stronger quake (M1.4, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.4
The mainshock
2 km West of Plodio
8 years ago · 24 Jan 2018, 12:22
Activity in the area right now (30 km radius)
1
last 24 hours
1
last 7 days
2
last 30 days
4 before1 after
this quake
Strongest of the sequence1.4

How often does it happen here?

about every ~4 months

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 37 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.

17675.0
Genovese earthquake
7 February 1767 · 49 km from here
VI-VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
20004.9
Monferrato earthquake
21 August 2000 · 47 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
19194.9
Alpi Marittime earthquake
28 November 1919 · 49 km from here
V-VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
18354.9
Cuneese earthquake
23 May 1835 · 48 km from here
VI-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

Southern Piemonte

The epicentre lies about 32 km from Southern Piemonte, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.3between 2 and 8 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

1.2
1 km West of Plodio
27 km South-East · 1 km
8 years ago
21 Feb 2018, 11:43
1.2
2 km East of Millesimo
26 km South-East · 1 km
8 years ago
2 Feb 2018, 12:11
1.1
2 km West of Plodio
27 km South-East · 1 km
8 years ago
31 Jan 2018, 12:45
0.7
3 km North-East of Cairo Montenotte
25 km South-East · 1 km
8 years ago
29 Jan 2018, 13:46
1.4
2 km West of Plodio
27 km South-East · 1 km
8 years ago
24 Jan 2018, 12:22

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).