All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 1 km North-East of Castelmola (ME)

6 years ago · 22 Nov 2019, 10:31

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

Stronger than 69% of Italian events in the past year

Where

1 km North-East of CastelmolaEarthquakes 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

46 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 ≈ 15 s

Animation sped up ~3× compared to reality.

  • Acireale
    29 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Messina
    41 km from the epicentre
    first tremor in ~8 s
    main shaking in ~13 s
  • Reggio di Calabria
    47 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Catania
    49 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 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

22 km
medium depth
2.5 times the height of Mount Everest

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

deeper 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?

Foreshock

In hindsight it was a foreshock: 6 years ago the same area had a stronger quake (M3.5). This can only be said after the fact — it was not predictable beforehand.

3.5
The mainshock
5 km North-East of Maletto
6 years ago · 18 Dec 2019, 00:48
Activity in the area right now (30 km radius)
0
last 24 hours
17
last 7 days
36
last 30 days
25 before20 after
this quake
Strongest of the sequence3.5

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: 2521 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 · 48 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18186.3
Catanese earthquake
20 February 1818 · 32 km from here
IX-XCompletely destructive: most buildings are destroyed.
17866.1
Golfo di Patti earthquake
10 March 1786 · 33 km from here
IXDestructive: many buildings partly or fully collapse.
17495.8
Messina earthquake
August 1749 · 43 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

Patti-Giardini

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

estimated maximum magnitude 7.1between 3 and 20 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

1.7
7 km West of Sant'Alfio
25 km West · 26 km
6 years ago
21 Nov 2019, 21:05
2.4
7 km West of Sant'Alfio
26 km West · 22 km
6 years ago
21 Nov 2019, 20:53
2.3
6 km West of Sant'Alfio
25 km South-West · 21 km
6 years ago
21 Nov 2019, 20:52
1.7
2 km East of Milo
20 km South-West · 10 km
6 years ago
23 Nov 2019, 00:42
1.9
2 km South-West of Sant'Alfio
23 km South-West · 8 km
6 years ago
23 Nov 2019, 01:59
1.8
3 km West of Moio Alcantara
23 km West · 24 km
6 years ago
20 Nov 2019, 19:35
1.8
2 km South-West of Sant'Alfio
22 km South-West · 5 km
6 years ago
20 Nov 2019, 05:43
1.7
6 km West of Sant'Alfio
26 km South-West · 3 km
6 years ago
28 Nov 2019, 17:39
1.7
2 km North-West of Rodì Milici
25 km North-West · 7 km
6 years ago
28 Nov 2019, 23:24
1.4
2 km North-West of Rodì Milici
24 km North-West · 7 km
6 years ago
29 Nov 2019, 01:59

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).