All earthquakes
0.9
very light
EARTHQUAKE DETAILS

12 km North-West of Bionaz

136 months ago · 4 Jul, 13:36

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

12 km North-West of BionazEarthquakes 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

16 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 ≈ 33 s

Animation sped up ~6× compared to reality.

  • Torino
    102 km from the epicentre
    first tremor in ~17 s
    main shaking in ~29 s
  • Varese
    112 km from the epicentre
    first tremor in ~19 s
    main shaking in ~32 s
  • Novara
    114 km from the epicentre
    first tremor in ~19 s
    main shaking in ~33 s
  • Gallarate
    115 km from the epicentre
    first tremor in ~19 s
    main shaking in ~33 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 (M2.9, 136 months ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.9
The mainshock
5 km East of Ollomont
136 months ago · 15 Jun, 05:14
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
0
last 30 days
12 before3 after
this quake
Strongest of the sequence2.9

How often does it happen here?

about every ~32 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 135 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.

18556.2
Vallese, Stalden-Visp earthquake
25 July 1855 · 45 km from here
15845.9
Vaud, Aigle earthquake
11 March 1584 · 50 km from here
19465.8
Vallese, Sierre earthquake
25 January 1946 · 40 km from here
15245.8
Vallese, Ardon earthquake
April 1524 · 33 km from here

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

The closest seismic structure

Western Valais

The epicentre lies about 18 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

1.1
18 km North of Bionaz
12 km North-East · 10 km
136 months ago
4 Jul, 10:02
1.5
5 km East of Ollomont
11 km South · 8 km
136 months ago
1 Jul, 20:42
1.0
21 km North of Bionaz
18 km North-East · 10 km
136 months ago
29 Jun, 13:06
0.9
2 km West of Quart
24 km South · 10 km
135 months ago
15 Jul, 17:58
1.4
22 km North-West of Bionaz
12 km North · 10 km
135 months ago
17 Jul, 19:38
2.7
136 months ago
20 Jun, 12:30
1.4
4 km North of Saint-Rhémy-en-Bosses
23 km South-West · 10 km
135 months ago
21 Jul, 11:59
1.8
6 km East of Ollomont
11 km South · 6 km
136 months ago
15 Jun, 07:56
0.6
7 km North of Ollomont
8 km South-West · 10 km
136 months ago
15 Jun, 05:47
1.2
6 km East of Ollomont
9 km South · 10 km
136 months ago
15 Jun, 05:22

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).

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