All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 1 km South-West of Torgnon (AO)

8 years ago · 16 Mar 2018, 19:41

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

Stronger than 63% of Italian events in the past year

Where

1 km South-West of TorgnonEarthquakes in the province of AostaEarthquakes in Valle d'Aosta

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

5 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.9kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×251 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 ≈ 28 s

Animation sped up ~5× compared to reality.

  • Torino
    81 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 s
  • Novara
    92 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Moncalieri
    95 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Varese
    97 km from the epicentre
    first tremor in ~16 s
    main shaking in ~28 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

10 km
medium depth
1.1 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 (M1.5, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.5
The mainshock
5 km North-East of Bionaz
8 years ago · 12 Mar 2018, 23:07
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
2
last 30 days
2 before2 after
this quake
Strongest of the sequence1.5

How often does it happen here?

about every ~40 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 107 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.

18555.3
Vallese, Stalden-Visp earthquake
26 July 1855 · 50 km from here
18805.2
Vallese, Embd earthquake
4 July 1880 · 48 km from here
19055.1
Haute-Savoie, Vallorcine earthquake
29 April 1905 · 48 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18925.0
Valle d'Aosta earthquake
5 March 1892 · 33 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Western Valais

The epicentre lies about 42 km from Western Valais, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.0between 3 and 15 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
5 km North-East of Bionaz
16 km North · 10 km
8 years ago
12 Mar 2018, 23:07
0.8
1 km North-West of Issogne
19 km South-East · 10 km
8 years ago
23 Feb 2018, 10:13
0.8
2 km North of Issogne
18 km South-East · 9 km
8 years ago
13 Apr 2018, 09:31
0.7
3 km North of Quart
12 km West · 12 km
8 years ago
14 Apr 2018, 21:41

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).