All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 2 km North-East of Milo (CT)

3 years ago · 10 Aug 2023, 20:41

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

2 km North-East of MiloEarthquakes in the province of CataniaEarthquakes in Sicilia

Volcanic area: Mount Etna

Here the ground shakes mostly because of moving magma and underground fluids, not colliding plates: events are typically shallow, frequent and organised in swarms. This activity is constantly monitored by INGV.

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

61 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 ≈ 19 s

Animation sped up ~4× compared to reality.

  • Acireale
    13 km from the epicentre
    first tremor in ~2 s
    main shaking in ~4 s
  • Catania
    31 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Messina
    61 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • Reggio di Calabria
    66 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 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

6 km
shallow

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

shallower than the area average (~13 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?

Seismic swarm

It is part of a seismic swarm: many closely spaced quakes in the same area, with no dominant shock. A typical, well-known behaviour of some Italian areas.

3.2
The mainshock
5 km East of Maletto
3 years ago · 30 Aug 2023, 18:27
Activity in the area right now (30 km radius)
0
last 24 hours
17
last 7 days
32
last 30 days
36 before55 after
this quake
Strongest of the sequence3.2

How often does it happen here?

about every ~2 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 2616 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.

18186.3
Catanese earthquake
20 February 1818 · 16 km from here
IX-XCompletely destructive: most buildings are destroyed.
17866.1
Golfo di Patti earthquake
10 March 1786 · 41 km from here
IXDestructive: many buildings partly or fully collapse.
17805.5
Sicilia nord-orientale earthquake
28 March 1780 · 22 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18485.5
Golfo di Catania earthquake
11 January 1848 · 37 km from here
VIII-IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Gela-Catania

The epicentre lies about 10 km from Gela-Catania, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 3 and 10 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

1.4
2 km South of Zafferana Etnea
8 km South-West · 6 km
3 years ago
11 Aug 2023, 05:49
1.5
3 years ago
10 Aug 2023, 07:21
1.5
3 years ago
12 Aug 2023, 23:39
1.6
10 km South of Moio Alcantara
11 km North-West · 2 km
3 years ago
8 Aug 2023, 17:42
1.1
3 years ago
14 Aug 2023, 15:22
1.4
11 km North of Maletto
23 km North-West · 29 km
3 years ago
14 Aug 2023, 15:25
1.7
10 km North-East of Maletto
21 km North-West · 27 km
3 years ago
14 Aug 2023, 19:00
1.1
3 km East of Sant'Alfio
2 km North · 4 km
3 years ago
14 Aug 2023, 23:04
1.7
1 km North of Giarre
6 km South-East · 10 km
3 years ago
5 Aug 2023, 08:24
1.1
3 years ago
17 Aug 2023, 04:26

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).