All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 3 km East of Arzignano (VI)

3 years ago · 2 Aug 2023, 01:44

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 39% of Italian events in the past year

Where

3 km East of ArzignanoEarthquakes in the province of VicenzaEarthquakes in Veneto

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

4 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 ≈ 17 s

Animation sped up ~3× compared to reality.

  • Vicenza
    15 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Verona
    29 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Padova
    43 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Rovigo
    60 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 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

9 km
shallow
1.1 times the height of Mount Everest

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

in line with the area average (~11 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 (M1.4, 3 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.4
The mainshock
3 km East of Tregnago
3 years ago · 13 Jul 2023, 07:43
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
0
last 30 days
1 before2 after
this quake
Strongest of the sequence1.4

How often does it happen here?

about every ~45 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 95 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.

11176.5
Veronese earthquake
3 January 1117 · 40 km from here
IXDestructive: many buildings partly or fully collapse.
18915.9
Valle d'Illasi earthquake
7 June 1891 · 17 km from here
IXDestructive: many buildings partly or fully collapse.
18365.5
Asolano earthquake
12 June 1836 · 47 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19084.9
Valle d'Illasi earthquake
15 March 1908 · 17 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.

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

The closest seismic structure

Schio-Vicenza

The epicentre lies about 13 km from Schio-Vicenza, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.3between 1 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

0.9
3 years ago
5 Aug 2023, 05:09
1.0
3 km East of Arzignano
1 km North · 9 km
3 years ago
10 Aug 2023, 01:18
1.4
3 km East of Tregnago
13 km West · 10 km
3 years ago
13 Jul 2023, 07:43

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).