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3.4
weak
EARTHQUAKE DETAILS

M3.4 earthquake · 4 km West of Capizzi (ME)

6 years ago · 16 Jul 2020, 12:16

A weak earthquake, felt by some of the population. At only a few km deep the shaking is felt more sharply at the surface.

No. 8 of the month in ItalyStronger than 99% of Italian events in the past year

Where

4 km West of CapizziEarthquakes in the province of MessinaEarthquakes in Sicilia

How far away could it be felt?

An estimate of how far people may have felt this quake.

  • up to ~1 km · felt by many people, especially on upper floors
  • up to ~21 km · felt only by some, at rest
    ≈ 53,000 people live in this area

The coloured rings on the map below show these distances.

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

42 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.9tof TNT equivalent
7.9 lightning bolts
M3
×4 the energy of a magnitude 3 earthquake
M2this quakeM4

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 ≈ 24 s

Animation sped up ~5× compared to reality.

  • Caltanissetta
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Catania
    67 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Acireale
    68 km from the epicentre
    first tremor in ~11 s
    main shaking in ~20 s
  • Gela
    85 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 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

5 km
shallow

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

shallower than the area average (~17 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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 19 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
10
last 30 days
22 before19 after
this quake
Strongest of the sequence2.3

How often does it happen here?

about every ~36 days

Within 50 km of this epicentre, a magnitude ≥ 3 earthquake has occurred on average this often: 120 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.
16135.6
Monti Nebrodi earthquake
25 August 1613 · 42 km from here
IXDestructive: many buildings partly or fully collapse.
17395.4
Monti Nebrodi earthquake
10 May 1739 · 37 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
18195.4
Monti Madonie earthquake
24 February 1819 · 37 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

Gela-Catania

The epicentre lies about 48 km from Gela-Catania, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 3 and 10 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

1.9
5 km West of Capizzi
2 km South-West · 7 km
6 years ago
16 Jul 2020, 15:13
1.5
3 km South of San Teodoro
22 km East · 29 km
6 years ago
16 Jul 2020, 01:55
1.2
4 km South-West of Capizzi
2 km South-East · 10 km
6 years ago
17 Jul 2020, 09:32
1.4
2 km East of Castel di Lucio
13 km West · 10 km
6 years ago
18 Jul 2020, 08:42
1.7
4 km West of Capizzi
1 km South · 10 km
6 years ago
18 Jul 2020, 22:08
1.6
3 km West of Capizzi
1 km East · 7 km
6 years ago
19 Jul 2020, 03:18
2.2
3 km South of San Fratello
17 km North-East · 9 km
6 years ago
6 Jul 2020, 06:24
1.5
6 km North-West of Troina
16 km East · 20 km
6 years ago
26 Jul 2020, 20:36
1.4
2 km South-East of San Fratello
20 km North-East · 11 km
6 years ago
5 Jul 2020, 20:47
1.9
4 km South-West of San Fratello
16 km North-East · 9 km
6 years ago
5 Jul 2020, 16:54

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).