All earthquakes
1.6
very light
EARTHQUAKE DETAILS

M1.6 offshore earthquake

9 years ago · 7 Mar 2017, 08:46

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 74% of Italian events in the past year

Where

Nearest Italian town: Leni (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

15 events
Magnitude:lightweakmoderatestrong

The energy released

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

3.8kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×126 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.

  • Bagheria
    95 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Messina
    96 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Palermo
    106 km from the epicentre
    first tremor in ~18 s
    main shaking in ~30 s
  • Acireale
    109 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

5 km
shallow

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

shallower than the area average (~31 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 (M3.7, 9 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.7
The mainshock
18 km South of Leni
9 years ago · 27 Feb 2017, 07:20
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
12
last 30 days
11 before3 after
this quake
Strongest of the sequence3.7

How often does it happen here?

about every ~5 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 887 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 · 31 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
19805.7
Tirreno meridionale earthquake
28 May 1980 · 18 km from here
VI-VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
16135.6
Monti Nebrodi earthquake
25 August 1613 · 46 km from here
IXDestructive: many buildings partly or fully collapse.
20045.4
Isole Eolie earthquake
5 May 2004 · 30 km from here
IVModerate: felt by many indoors; glasses and dishes rattle.

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

The closest seismic structure

Southern Tyrrhenian

The epicentre sits above this source area: the deep structure where this area's earthquakes can originate.

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

1.9
Isole Eolie (Messina)
10 km North · 17 km
9 years ago
10 Mar 2017, 16:14
2.4
Isole Eolie (Messina)
3 km North · 9 km
9 years ago
1 Mar 2017, 20:36
3.0
Isole Eolie (Messina)
10 km North · 21 km
9 years ago
1 Mar 2017, 13:56
2.5
23 km South of Leni
26 km East · 11 km
9 years ago
28 Feb 2017, 23:33
1.8
21 km South of Leni
27 km East · 19 km
9 years ago
27 Feb 2017, 10:09
2.1
9 years ago
27 Feb 2017, 08:36
1.8
21 km South of Leni
28 km East · 11 km
9 years ago
27 Feb 2017, 07:27
3.4
17 km South of Leni
29 km East · 19 km
9 years ago
27 Feb 2017, 07:21
3.7
18 km South of Leni
27 km East · 22 km
9 years ago
27 Feb 2017, 07:20
1.6
Isole Eolie (Messina)
8 km North-East · 7 km
9 years ago
21 Feb 2017, 18:50

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).