All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 3 km East of Merì (ME)

3 years ago · 29 Jul 2023, 20:31

A very light earthquake, probably not felt by people. Being deep, it is felt less at the surface.

Stronger than 69% of Italian events in the past year

Where

3 km East of MerìEarthquakes in the province of MessinaEarthquakes in Sicilia

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

37 events
Magnitude:lightweakmoderatestrong

The energy released

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

2.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×178 its energy
M1this quakeM3

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 ≈ 26 s

Animation sped up ~5× compared to reality.

  • Messina
    21 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Reggio di Calabria
    38 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Acireale
    59 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Catania
    78 km from the epicentre
    first tremor in ~15 s
    main shaking in ~26 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

43 km
deep
4.9 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~29 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: 3 years ago the same area had a stronger quake (M2.5). This can only be said after the fact — it was not predictable beforehand.

2.5
The mainshock
16 km North-West of Villafranca Tirrena
3 years ago · 16 Aug 2023, 09:33
Activity in the area right now (30 km radius)
0
last 24 hours
15
last 7 days
51
last 30 days
22 before14 after
this quake
Strongest of the sequence2.5

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: 2477 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.

19087.1
Stretto di Messina earthquake
28 December 1908 · 35 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17866.1
Golfo di Patti earthquake
10 March 1786 · 24 km from here
IXDestructive: many buildings partly or fully collapse.
19786.0
Golfo di Patti earthquake
15 April 1978 · 31 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
17495.8
Messina earthquake
August 1749 · 24 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

Milazzo-Eolie

The epicentre lies about 7 km from Milazzo-Eolie, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 1 and 25 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

2.1
19 km North of Villafranca Tirrena
27 km North-East · 118 km
3 years ago
30 Jul 2023, 02:11
2.0
0 km East of Oliveri
21 km West · 8 km
3 years ago
29 Jul 2023, 12:21
2.2
19 km North of Villafranca Tirrena
28 km North-East · 114 km
3 years ago
30 Jul 2023, 08:01
1.7
7 km South-West of Milazzo
10 km West · 14 km
3 years ago
30 Jul 2023, 08:05
1.3
12 km North of Villafranca Tirrena
23 km North-East · 8 km
3 years ago
28 Jul 2023, 21:04
1.1
7 km North of Patti
25 km West · 10 km
3 years ago
28 Jul 2023, 19:40
1.5
9 km South-East of Alì Terme
28 km South-East · 8 km
3 years ago
28 Jul 2023, 11:49
0.5
2 km South-West of Tripi
22 km South-West · 7 km
3 years ago
28 Jul 2023, 02:12
1.4
1 km East of Basicò
20 km South-West · 8 km
3 years ago
28 Jul 2023, 01:41
1.4
2 km East of Gioiosa Marea
30 km West · 16 km
3 years ago
2 Aug 2023, 10:39

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).