All earthquakes
1.7
very light
EARTHQUAKE DETAILS

M1.7 earthquake · 1 km West of Gaggi (ME)

11 years ago · 14 Mar 2015, 04:04

A very light earthquake, probably not felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 78% of Italian events in the past year

Where

1 km West of GaggiEarthquakes 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

28 events
Magnitude:lightweakmoderatestrong

The energy released

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

5.4kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×89 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 ≈ 17 s

Animation sped up ~3× compared to reality.

  • Acireale
    26 km from the epicentre
    first tremor in ~6 s
    main shaking in ~11 s
  • Messina
    46 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Catania
    46 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Reggio di Calabria
    52 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 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

27 km
medium depth
3 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

deeper than the area average (~13 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 (M2.6, 11 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.6
The mainshock
2 km South of Floresta
11 years ago · 21 Feb 2015, 21:23
Activity in the area right now (30 km radius)
0
last 24 hours
17
last 7 days
37
last 30 days
17 before10 after
this quake
Strongest of the sequence2.6

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: 2658 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.

18186.3
Catanese earthquake
20 February 1818 · 29 km from here
IX-XCompletely destructive: most buildings are destroyed.
17866.1
Golfo di Patti earthquake
10 March 1786 · 31 km from here
IXDestructive: many buildings partly or fully collapse.
17495.8
Messina earthquake
August 1749 · 47 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
16135.6
Monti Nebrodi earthquake
25 August 1613 · 47 km from here
IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Patti-Giardini

The epicentre lies about 5 km from Patti-Giardini, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 3 and 20 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
1 km East of Graniti
4 km North-East · 10 km
11 years ago
14 Mar 2015, 11:30
1.7
11 years ago
13 Mar 2015, 18:49
1.7
2 km West of Santa Venerina
21 km South-West · 10 km
11 years ago
16 Mar 2015, 21:28
1.5
2 km West of Milo
17 km South-West · 9 km
11 years ago
10 Mar 2015, 03:03
1.0
3 km West of Basicò
27 km North-West · 10 km
11 years ago
9 Mar 2015, 13:11
2.3
3 km East of Milo
15 km South-West · 9 km
11 years ago
4 Mar 2015, 15:41
1.8
4 km West of Mascali
13 km South-West · 9 km
11 years ago
4 Mar 2015, 13:58
2.4
3 km East of Milo
15 km South-West · 8 km
11 years ago
4 Mar 2015, 13:30
2.1
2 km West of Furnari
28 km North-West · 9 km
11 years ago
1 Mar 2015, 04:17
1.6
2 km South of Giarre
19 km South · 9 km
11 years ago
28 Feb 2015, 09:12

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).