All earthquakes
1.8
very light
EARTHQUAKE DETAILS

M1.8 offshore earthquake

5 years ago · 12 Jun 2021, 15:05

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

Stronger than 82% of Italian events in the past year

Where

Nearest Italian town: Villafranca Tirrena (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

24 events
Magnitude:lightweakmoderatestrong

The energy released

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

7.6kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×63 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 ≈ 36 s

Animation sped up ~7× compared to reality.

  • Messina
    39 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 s
  • Reggio di Calabria
    55 km from the epicentre
    first tremor in ~15 s
    main shaking in ~26 s
  • Lamezia Terme
    89 km from the epicentre
    first tremor in ~19 s
    main shaking in ~33 s
  • Acireale
    103 km from the epicentre
    first tremor in ~21 s
    main shaking in ~36 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

71 km
deep
8 times the height of Mount Everest

Being deep, it is felt less at the surface.

in line with the area average (~71 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 (M2.9, 5 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.9
The mainshock
18 km North of Milazzo
5 years ago · 8 Jun 2021, 15:35
Activity in the area right now (30 km radius)
2
last 24 hours
6
last 7 days
19
last 30 days
13 before10 after
this quake
Strongest of the sequence2.9

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: 1875 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 · 49 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18946.1
Calabria meridionale earthquake
16 November 1894 · 48 km from here
IXDestructive: many buildings partly or fully collapse.
19786.0
Golfo di Patti earthquake
15 April 1978 · 33 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19285.9
Calabria centro-meridionale earthquake
7 March 1928 · 48 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Bagnara-Bovalino

The epicentre lies about 24 km from Bagnara-Bovalino, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 3 and 12 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
Tirreno Meridionale [Mare]
11 km North-East · 150 km
5 years ago
12 Jun 2021, 05:40
2.9
18 km North of Milazzo
25 km South-West · 166 km
5 years ago
8 Jun 2021, 15:35
2.3
22 km North of Milazzo
16 km South-West · 132 km
5 years ago
6 Jun 2021, 14:36
2.4
5 years ago
6 Jun 2021, 09:29
1.8
5 years ago
5 Jun 2021, 22:28
2.2
Tirreno Meridionale [Mare]
10 km East · 141 km
5 years ago
5 Jun 2021, 11:20
2.0
5 years ago
5 Jun 2021, 05:04
2.7
5 years ago
25 Jun 2021, 13:38
1.9
17 km South-East of Lipari
22 km West · 238 km
5 years ago
25 Jun 2021, 20:48
2.5
23 km North of Milazzo
16 km South-West · 141 km
5 years ago
27 Jun 2021, 04:05

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).