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2.2
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EARTHQUAKE DETAILS

M2.2 earthquake · 24 km South-West of Leni (ME)

9 years ago · 21 Jan 2017, 05:05

A light earthquake, rarely felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 92% of Italian events in the past year

Where

24 km South-West of LeniEarthquakes 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

19 events
Magnitude:lightweakmoderatestrong

The energy released

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

30kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×16 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 ≈ 31 s

Animation sped up ~6× compared to reality.

  • Messina
    80 km from the epicentre
    first tremor in ~13 s
    main shaking in ~23 s
  • Acireale
    97 km from the epicentre
    first tremor in ~16 s
    main shaking in ~28 s
  • Reggio di Calabria
    99 km from the epicentre
    first tremor in ~17 s
    main shaking in ~29 s
  • Bagheria
    107 km from the epicentre
    first tremor in ~18 s
    main shaking in ~31 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

10 km
shallow
1.1 times the height of Mount Everest

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

shallower than the area average (~26 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 (M3.4, 9 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.4
The mainshock
16 km South of Santa Marina Salina
9 years ago · 20 Jan 2017, 10:30
Activity in the area right now (30 km radius)
0
last 24 hours
6
last 7 days
20
last 30 days
7 before11 after
this quake
Strongest of the sequence3.4

How often does it happen here?

about every ~4 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 1149 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 · 47 km from here
IXDestructive: many buildings partly or fully collapse.
19786.0
Golfo di Patti earthquake
15 April 1978 · 39 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18235.8
Sicilia settentrionale earthquake
5 March 1823 · 36 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
19805.7
Tirreno meridionale earthquake
28 May 1980 · 34 km from here
VI-VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.

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

The closest seismic structure

Southern Tyrrhenian

The epicentre lies about 5 km from Southern Tyrrhenian, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 8.2between 2 and 18 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

3.4
9 years ago
20 Jan 2017, 10:30
2.6
10 km West of Leni
15 km North-East · 21 km
9 years ago
18 Jan 2017, 17:54
3.0
10 km West of Leni
15 km North-East · 23 km
9 years ago
17 Jan 2017, 23:50
2.2
Costa Siciliana nord-orientale (Messina)
15 km West · 6 km
9 years ago
27 Jan 2017, 18:38
1.6
9 years ago
28 Jan 2017, 01:18
2.5
20 km North of Piraino
18 km South-East · 123 km
9 years ago
9 Jan 2017, 18:03
2.6
18 km South-West of Leni
6 km North-East · 21 km
9 years ago
1 Feb 2017, 18:58
1.7
17 km South-West of Leni
6 km North-East · 20 km
9 years ago
1 Feb 2017, 19:01
2.3
19 km South-West of Leni
5 km North-East · 20 km
9 years ago
2 Feb 2017, 00:18
1.7
20 km South-West of Leni
4 km East · 22 km
9 years ago
2 Feb 2017, 00:47

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).