All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 3 km South-East of Arco (TN)

3 years ago · 4 Nov 2022, 17:13

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

Stronger than 39% of Italian events in the past year

Where

3 km South-East of ArcoEarthquakes 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

16 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×708 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 ≈ 20 s

Animation sped up ~4× compared to reality.

  • Trento
    21 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 s
  • Verona
    52 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Vicenza
    64 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Brescia
    68 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 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

14 km
medium depth
1.5 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

deeper than the area average (~7 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, 3 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.9
The mainshock
2 km South-West of Vallarsa
3 years ago · 21 Oct 2022, 09:15
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
6
last 30 days
10 before5 after
this quake
Strongest of the sequence1.9

How often does it happen here?

about every ~34 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 125 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.

18915.9
Valle d'Illasi earthquake
7 June 1891 · 43 km from here
IXDestructive: many buildings partly or fully collapse.
12225.7
Bresciano-Veronese earthquake
25 December 1222 · 47 km from here
19015.4
Garda occidentale earthquake
30 October 1901 · 49 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19325.2
Garda orientale earthquake
19 February 1932 · 34 km from here
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

Giudicarie

The epicentre sits above this source area: the deep structure where this area's earthquakes can originate.

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

1.3
1 km East of Volano
14 km East · 12 km
3 years ago
4 Nov 2022, 22:23
1.2
2 km South of Arco
1 km West · 14 km
3 years ago
4 Nov 2022, 02:19
0.9
6 km South-East of Vallarsa
26 km South-East · 11 km
3 years ago
2 Nov 2022, 04:08
1.0
2 km South-West of Mori
7 km South · 15 km
3 years ago
11 Nov 2022, 10:48
1.0
3 years ago
26 Oct 2022, 01:39
1.5
1 km West of Ala
21 km South-East · 11 km
3 years ago
15 Nov 2022, 09:33
1.2
4 km North-West of Ala
18 km South-East · 13 km
3 years ago
23 Oct 2022, 12:50
1.3
3 years ago
21 Oct 2022, 12:46
1.9
2 km South-West of Vallarsa
19 km South-East · 12 km
3 years ago
21 Oct 2022, 09:15
1.2
4 km South-East of Brentonico
15 km South-East · 13 km
3 years ago
20 Oct 2022, 18:49

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).