All earthquakes
1.9
very light
EARTHQUAKE DETAILS

M1.9 earthquake · 7 km North of Gioiosa Marea (ME)

3 years ago · 17 Aug 2023, 00:43

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

Stronger than 85% of Italian events in the past year

Where

7 km North of Gioiosa MareaEarthquakes 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.

11kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×45 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 ≈ 41 s

Animation sped up ~8× compared to reality.

  • Messina
    54 km from the epicentre
    first tremor in ~21 s
    main shaking in ~36 s
  • Acireale
    69 km from the epicentre
    first tremor in ~22 s
    main shaking in ~38 s
  • Reggio di Calabria
    72 km from the epicentre
    first tremor in ~23 s
    main shaking in ~39 s
  • Catania
    83 km from the epicentre
    first tremor in ~24 s
    main shaking in ~41 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

115 km
deep
13 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~27 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 (M2.4). This can only be said after the fact — it was not predictable beforehand.

2.4
The mainshock
3 km East of Floresta
3 years ago · 25 Aug 2023, 04:55
Activity in the area right now (30 km radius)
0
last 24 hours
12
last 7 days
43
last 30 days
10 before26 after
this quake
Strongest of the sequence2.4

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: 1982 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.

17866.1
Golfo di Patti earthquake
10 March 1786 · 17 km from here
IXDestructive: many buildings partly or fully collapse.
19786.0
Golfo di Patti earthquake
15 April 1978 · 25 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18235.8
Sicilia settentrionale earthquake
5 March 1823 · 49 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
16135.6
Monti Nebrodi earthquake
25 August 1613 · 15 km from here
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 11 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

1.1
1 km South-East of Novara di Sicilia
30 km South-East · 5 km
3 years ago
17 Aug 2023, 03:50
0.6
3 years ago
18 Aug 2023, 05:19
1.5
3 years ago
18 Aug 2023, 15:32
0.9
14 km North-West of Milazzo
21 km East · 10 km
3 years ago
20 Aug 2023, 04:52
1.1
3 km West of Mazzarrà Sant'Andrea
24 km South-East · 12 km
3 years ago
10 Aug 2023, 04:54
1.7
4 km South-West of Torrenova
27 km South-West · 7 km
3 years ago
24 Aug 2023, 21:16
2.4
3 km East of Floresta
28 km South · 35 km
3 years ago
25 Aug 2023, 04:55
1.7
3 years ago
26 Aug 2023, 01:17
1.1
4 km North of Montalbano Elicona
23 km South-East · 11 km
3 years ago
7 Aug 2023, 15:11
1.3
0 km East of Basicò
23 km South-East · 8 km
3 years ago
30 Aug 2023, 07:25

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).