All earthquakes
1.0
very light
EARTHQUAKE DETAILS

3 km South-West of Pollina

127 months ago · 23 Mar, 23:16

A very light earthquake, probably not felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 30% of Italian events in the past year

Where

3 km South-West of PollinaEarthquakes in the province of PalermoEarthquakes 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

8 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 its energy
M0this quakeM2

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 ≈ 25 s

Animation sped up ~5× compared to reality.

  • Bagheria
    54 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Caltanissetta
    55 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Palermo
    70 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Agrigento
    86 km from the epicentre
    first tremor in ~14 s
    main shaking in ~25 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

6 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?

Foreshock

In hindsight it was a foreshock: 126 months ago the same area had a stronger quake (M1.8). This can only be said after the fact — it was not predictable beforehand.

1.8
The mainshock
3 km East of Pettineo
126 months ago · 14 Apr, 21:49
Activity in the area right now (30 km radius)
1
last 24 hours
2
last 7 days
15
last 30 days
3 before4 after
this quake
Strongest of the sequence1.8

How often does it happen here?

about every ~10 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 424 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 · 32 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
18195.4
Monti Madonie earthquake
24 February 1819 · 6 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18185.3
Monti Madonie earthquake
8 September 1818 · 18 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19675.3
Monti Nebrodi earthquake
31 October 1967 · 30 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

Southern Tyrrhenian S

The epicentre lies about 44 km from Southern Tyrrhenian S, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.0between 3 and 16 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

1.3
4 km West of Geraci Siculo
15 km South · 9 km
127 months ago
21 Mar, 00:26
0.8
3 km West of Pollina
1 km North-West · 5 km
127 months ago
18 Mar, 07:01
1.2
4 km South-East of Scillato
19 km South-West · 10 km
127 months ago
5 Apr, 03:52
0.7
3 km East of Geraci Siculo
17 km South-East · 7 km
127 months ago
10 Mar, 23:55
0.8
6 km South-East of Castel di Lucio
25 km South-East · 8 km
126 months ago
6 Apr, 17:59
1.1
8 km South-East of Isnello
14 km South · 10 km
126 months ago
9 Apr, 11:07
1.8
3 km East of Pettineo
19 km East · 4 km
126 months ago
14 Apr, 21:49

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).

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