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EARTHQUAKE DETAILS

M2.0 earthquake · 5 km South-West of Valloriate (CN)

4 years ago · 29 Nov 2021, 19:04

A light earthquake, rarely felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 88% of Italian events in the past year

Where

5 km South-West of ValloriateEarthquakes 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

25 events
Magnitude:lightweakmoderatestrong

The energy released

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

15kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×32 its energy
M1this quakeM3

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 ≈ 26 s

Animation sped up ~5× compared to reality.

  • Cuneo
    21 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 s
  • Sanremo
    63 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Moncalieri
    80 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 s
  • Savona
    90 km from the epicentre
    first tremor in ~15 s
    main shaking in ~26 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

12 km
medium depth
1.3 times the height of Mount Everest

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

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?

Aftershock

It is an aftershock: it follows a stronger quake (M2.1, 4 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.1
The mainshock
4 km South-East of Castelmagno
4 years ago · 10 Nov 2021, 06:33
Activity in the area right now (30 km radius)
0
last 24 hours
6
last 7 days
14
last 30 days
10 before14 after
this quake
Strongest of the sequence2.1

How often does it happen here?

about every ~19 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 226 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.

15645.8
Lantosque earthquake
20 July 1564 · 31 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
16445.7
Alpes Niçoises earthquake
15 February 1644 · 37 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
16185.6
Alpes Niçoises earthquake
18 January 1618 · 38 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19194.9
Alpi Marittime earthquake
28 November 1919 · 37 km from here
V-VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.

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

The closest seismic structure

Brianconnais

The epicentre lies about 35 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

1.2
5 km South-East of Vinadio
17 km West · 11 km
4 years ago
3 Dec 2021, 19:57
1.3
4 km North-West of Valdieri
6 km South-West · 11 km
4 years ago
4 Dec 2021, 14:12
1.2
4 years ago
8 Dec 2021, 12:34
1.0
4 km North of Demonte
8 km North-West · 11 km
4 years ago
8 Dec 2021, 23:17
0.9
3 km South of Robilante
15 km East · 1 km
4 years ago
19 Nov 2021, 10:42
1.4
6 km South-East of Vinadio
18 km West · 11 km
4 years ago
10 Dec 2021, 08:20
1.6
6 km South of Vinadio
18 km West · 11 km
4 years ago
18 Nov 2021, 21:26
1.1
5 km South of Vinadio
18 km West · 10 km
4 years ago
15 Nov 2021, 09:07
1.3
4 years ago
14 Dec 2021, 07:18
0.7
5 km South-East of Vinadio
15 km West · 11 km
4 years ago
16 Dec 2021, 04:24

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).