All earthquakes
0.9
very light
EARTHQUAKE DETAILS

M0.9 earthquake · 0 km West of Civezzano (TN)

4 years ago · 14 Oct 2021, 17:21

A very light earthquake, probably not felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 23% of Italian events in the past year

Where

0 km West of CivezzanoEarthquakes in the province of TrentoEarthquakes in Trentino-Alto Adige

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

31 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • Trento
    8 km from the epicentre
    first tremor in ~1 s
    main shaking in ~2 s
  • Bolzano
    45 km from the epicentre
    first tremor in ~8 s
    main shaking in ~13 s
  • Vicenza
    68 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Verona
    75 km from the epicentre
    first tremor in ~13 s
    main shaking in ~21 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

1 km
shallow

At only a few km deep the shaking is felt more sharply at the surface.

shallower than the area average (~6 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?

Foreshock

In hindsight it was a foreshock: 4 years ago the same area had a stronger quake (M1.3). This can only be said after the fact — it was not predictable beforehand.

1.3
The mainshock
1 km North-West of Albiano
4 years ago · 21 Oct 2021, 18:11
Activity in the area right now (30 km radius)
2
last 24 hours
5
last 7 days
14
last 30 days
17 before13 after
this quake
Strongest of the sequence1.3

How often does it happen here?

about every ~49 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 87 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.

18765.1
Monte Baldo earthquake
29 April 1876 · 50 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19764.9
Garda settentrionale earthquake
13 December 1976 · 37 km from here
VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
19484.9
Garda settentrionale earthquake
19 July 1948 · 46 km from here
V-VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
18764.9
Monte Baldo earthquake
2 May 1876 · 49 km from here
VI-VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.

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

The closest seismic structure

Giudicarie

The epicentre lies about 8 km from Giudicarie, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.8between 5 and 12 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
1 km West of Albiano
4 km North · 1 km
4 years ago
14 Oct 2021, 17:08
0.9
2 km North-West of Albiano
5 km North · 1 km
4 years ago
14 Oct 2021, 12:06
0.8
0 km North of Cembra Lisignago
9 km North-East · 10 km
5 years ago
11 Oct 2021, 12:09
1.1
2 km North-West of Albiano
6 km North · 1 km
5 years ago
11 Oct 2021, 12:08
0.8
2 km East of Giovo
11 km North · 1 km
4 years ago
18 Oct 2021, 12:07
0.9
1 km West of Albiano
4 km North · 1 km
5 years ago
7 Oct 2021, 17:28
1.0
2 km North-West of Albiano
5 km North · 1 km
5 years ago
7 Oct 2021, 17:07
1.3
1 km North-West of Albiano
5 km North · 1 km
4 years ago
21 Oct 2021, 18:11
1.0
0 km North of Albiano
5 km North · 1 km
5 years ago
4 Oct 2021, 12:36
0.9
2 km West of Albiano
5 km North · 1 km
4 years ago
25 Oct 2021, 12:10

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).