All earthquakes
1.0
very light
EARTHQUAKE DETAILS

M1.0 earthquake outside Italy

5 years ago · 8 Sept 2021, 00:40

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

Where

Nearest Italian town: Livigno (SO)Earthquakes in the province of SondrioEarthquakes in Lombardia

Epicentre abroad

The epicentre lies outside Italy's borders. The quake appears here because the INGV seismic network also records events close to Italy, which can be felt on Italian territory.

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

8 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 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 ≈ 38 s

Animation sped up ~7× compared to reality.

  • Bolzano
    94 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Trento
    102 km from the epicentre
    first tremor in ~17 s
    main shaking in ~29 s
  • Bergamo
    119 km from the epicentre
    first tremor in ~20 s
    main shaking in ~34 s
  • Brescia
    131 km from the epicentre
    first tremor in ~22 s
    main shaking in ~38 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
1.3 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?

Aftershock

It is an aftershock: it follows a stronger quake (M1.9, 5 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.9
The mainshock
19 km North of Livigno
5 years ago · 15 Aug 2021, 08:02
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
9
last 30 days
4 before3 after
this quake
Strongest of the sequence1.9

How often does it happen here?

about every ~3 months

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

12956.2
Grigioni, Churwalden earthquake
3 September 1295 · 50 km from here
16225.4
Bassa Engadina, Ftan earthquake
3 August 1622 · 13 km from here
18275.0
Bassa Engadina, Ardez earthquake
2 April 1827 · 6 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
16955.0
Grigioni, Region Praettigau earthquake
11 September 1695 · 44 km from here

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

The closest seismic structure

Brenner

The epicentre lies about 85 km from Brenner, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.2between 4 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

0.8
8 km South-West of Tubre
22 km South-East · 11 km
5 years ago
29 Aug 2021, 05:54
1.7
4 km South-West of Valdidentro
28 km South · 10 km
5 years ago
22 Sept 2021, 10:50
0.1
3 km North of Bormio
27 km South-East · 6 km
5 years ago
19 Aug 2021, 21:19
0.6
15 km North of Livigno
5 km South · 9 km
5 years ago
30 Sept 2021, 01:12
1.1
2 km West of Bormio
28 km South-East · 7 km
5 years ago
16 Aug 2021, 15:33
1.9
19 km North of Livigno
1 km South-West · 9 km
5 years ago
15 Aug 2021, 08:02
1.7
17 km North-West of Tubre
17 km North-East · 11 km
5 years ago
6 Oct 2021, 02:40

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).