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2.3
light
EARTHQUAKE DETAILS

M2.3 earthquake · 3 km West of Macugnaga (VB)

2 years ago · 27 Mar 2024, 15:45

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

Stronger than 93% of Italian events in the past year

Where

3 km West of MacugnagaEarthquakes in the province of Verbano-Cusio-OssolaEarthquakes 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

5 events
Magnitude:lightweakmoderatestrong

The energy released

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

43kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×11 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 ≈ 23 s

Animation sped up ~4× compared to reality.

  • Varese
    69 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Gallarate
    74 km from the epicentre
    first tremor in ~13 s
    main shaking in ~21 s
  • Novara
    79 km from the epicentre
    first tremor in ~13 s
    main shaking in ~23 s
  • Busto Arsizio
    81 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 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 (~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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 2 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
0
last 30 days
2 before2 after
this quake
Strongest of the sequence1.3

How often does it happen here?

about every ~2 months

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 62 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 · 31 km from here
17555.7
Vallese, Brig-Naters earthquake
9 December 1755 · 40 km from here
18555.5
Vallese, Stalden-Visp earthquake
26 July 1855 · 30 km from here
18375.4
Berna, Birgisch earthquake
24 January 1837 · 40 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 32 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

1.3
3 km North-West of Macugnaga
1 km North · 12 km
2 years ago
27 Mar 2024, 17:27
1.0
20 km North of Valtournenche
27 km North-West · 7 km
2 years ago
20 Mar 2024, 21:11
1.3
Confine Italia-Svizzera (SVIZZERA)
29 km North-West · 9 km
2 years ago
16 Apr 2024, 10:01
0.6
14 km North-West of Macugnaga
11 km North-West · 11 km
2 years ago
7 Mar 2024, 09:23

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).