All earthquakes
1.3
very light
EARTHQUAKE DETAILS

13 km West of Viareggio

132 months ago · 26 Oct, 23:46

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

Stronger than 55% of Italian events in the past year

Where

13 km West of ViareggioEarthquakes in the province of LuccaEarthquakes in Toscana

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

22 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×355 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 ≈ 9 s

Animation sped up ~2× compared to reality.

  • Viareggio
    13 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Pisa
    23 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 s
  • Massa
    27 km from the epicentre
    first tremor in ~5 s
    main shaking in ~8 s
  • Lucca
    29 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 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
medium depth
1.1 times the height of Mount Everest

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

in line with the area average (~9 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 (M1.8, 132 months ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.8
The mainshock
5 km South-West of Pisa
132 months ago · 22 Oct, 05:15
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
68
last 30 days
7 before14 after
this quake
Strongest of the sequence1.8

How often does it happen here?

about every ~38 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 112 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.

19206.5
Garfagnana earthquake
7 September 1920 · 43 km from here
XCompletely destructive: most buildings are destroyed.
18375.9
Lunigiana earthquake
11 April 1837 · 40 km from here
XCompletely destructive: most buildings are destroyed.
17405.6
Garfagnana earthquake
6 March 1740 · 41 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19145.6
Lucchesia earthquake
27 October 1914 · 40 km from here
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

Livorno Hills

The epicentre lies about 35 km from Livorno Hills, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.2between 1 and 7 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

1.8
5 km South-West of Pisa
22 km South-East · 9 km
132 months ago
22 Oct, 05:15
1.3
5 km West of Massa
24 km North · 10 km
132 months ago
21 Oct, 22:19
1.2
11 km South-East of Portovenere
23 km North-West · 1 km
132 months ago
21 Oct, 12:33
1.2
11 km South-East of Portovenere
23 km North-West · 1 km
132 months ago
21 Oct, 12:03
1.8
11 km South-East of Portovenere
22 km North-West · 1 km
132 months ago
4 Nov, 11:40
0.8
10 km South-East of Portovenere
24 km North-West · 1 km
132 months ago
4 Nov, 11:58
1.0
12 km South of Ameglia
21 km North-West · 1 km
132 months ago
4 Nov, 12:09
1.3
17 km South of Portovenere
21 km West · 1 km
132 months ago
4 Nov, 12:19
1.2
12 km South-East of Portovenere
22 km North-West · 1 km
132 months ago
4 Nov, 12:33
1.2
11 km South-East of Portovenere
22 km North-West · 1 km
132 months ago
4 Nov, 12:48

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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