All earthquakes
1.3
very light
EARTHQUAKE DETAILS

M1.3 offshore earthquake

3 years ago · 21 Apr 2023, 01:24

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 55% of Italian events in the past year

Where

Nearest Italian town: Leni (ME)Earthquakes in the province of MessinaEarthquakes in Sicilia

Epicentre at sea

The epicentre is at sea: for the same magnitude, the shaking is felt less on land, because the energy fades along the way before reaching the coast.

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

23 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×355 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 ≈ 32 s

Animation sped up ~6× compared to reality.

  • Messina
    96 km from the epicentre
    first tremor in ~16 s
    main shaking in ~28 s
  • Bagheria
    98 km from the epicentre
    first tremor in ~16 s
    main shaking in ~28 s
  • Palermo
    109 km from the epicentre
    first tremor in ~18 s
    main shaking in ~31 s
  • Acireale
    113 km from the epicentre
    first tremor in ~19 s
    main shaking in ~32 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

8 km
shallow

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

shallower than the area average (~36 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 (M3.6, 3 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.6
The mainshock
11 km West of Leni
3 years ago · 31 Mar 2023, 20:27
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
12
last 30 days
8 before14 after
this quake
Strongest of the sequence3.6

How often does it happen here?

about every ~5 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 849 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.

18235.8
Sicilia settentrionale earthquake
5 March 1823 · 37 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
19805.7
Tirreno meridionale earthquake
28 May 1980 · 19 km from here
VI-VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
16135.6
Monti Nebrodi earthquake
25 August 1613 · 49 km from here
IXDestructive: many buildings partly or fully collapse.
20045.4
Isole Eolie earthquake
5 May 2004 · 27 km from here
IVModerate: felt by many indoors; glasses and dishes rattle.

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

The closest seismic structure

Southern Tyrrhenian

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

estimated maximum magnitude 8.2between 2 and 18 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

1.6
Isole Eolie (Messina)
10 km South-East · 9 km
3 years ago
23 Apr 2023, 22:00
2.9
25 km West of Leni
6 km East · 20 km
3 years ago
24 Apr 2023, 00:53
1.7
Isole Eolie (Messina)
8 km South-East · 10 km
3 years ago
24 Apr 2023, 01:27
1.2
Isole Eolie (Messina)
8 km South-East · 10 km
3 years ago
24 Apr 2023, 01:28
2.3
Isole Eolie (Messina)
6 km East · 20 km
3 years ago
24 Apr 2023, 01:33
2.4
Isole Eolie (Messina)
11 km South-East · 8 km
3 years ago
24 Apr 2023, 04:23
2.4
Isole Eolie (Messina)
8 km South-East · 10 km
3 years ago
24 Apr 2023, 15:55
1.9
Isole Eolie (Messina)
5 km North-West · 10 km
3 years ago
7 May 2023, 03:23
1.7
Isole Eolie (Messina)
6 km North-West · 10 km
3 years ago
7 May 2023, 03:49
2.4
Isole Eolie (Messina)
11 km North-West · 19 km
3 years ago
7 May 2023, 07:09

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).