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2.5
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EARTHQUAKE DETAILS

M2.5 earthquake · 4 km North-West of Camaiore (LU)

6 years ago · 25 Oct 2019, 04:54

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

Stronger than 95% of Italian events in the past year

Where

4 km North-West of CamaioreEarthquakes 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

7 events
Magnitude:lightweakmoderatestrong

The energy released

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

85kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×5.6 its energy
M2this quakeM4

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 ≈ 7 s

Animation sped up ~1× compared to reality.

  • Viareggio
    8 km from the epicentre
    first tremor in ~2 s
    main shaking in ~3 s
  • Lucca
    17 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Massa
    17 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Carrara
    23 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 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.

in line with the area average (~11 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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 4 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
10
last 30 days
2 before4 after
this quake
Strongest of the sequence1.5

How often does it happen here?

about every ~57 days

Within 50 km of this epicentre, a magnitude ≥ 2.5 earthquake has occurred on average this often: 75 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 · 28 km from here
XCompletely destructive: most buildings are destroyed.
18375.9
Lunigiana earthquake
11 April 1837 · 28 km from here
XCompletely destructive: most buildings are destroyed.
17405.6
Garfagnana earthquake
6 March 1740 · 22 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19145.6
Lucchesia earthquake
27 October 1914 · 24 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

Garfagnana

The epicentre lies about 18 km from Garfagnana, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 1 and 10 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
5 km South-West of Carrara
21 km North-West · 10 km
6 years ago
26 Oct 2019, 22:41
1.2
6 years ago
27 Oct 2019, 13:03
1.3
4 km North-West of Camaiore
2 km North-East · 11 km
6 years ago
30 Oct 2019, 03:42
1.3
3 km North-West of Calci
27 km South-East · 8 km
6 years ago
14 Oct 2019, 21:02
0.9
3 km West of Calci
27 km South-East · 8 km
7 years ago
14 Oct 2019, 00:14
1.5
4 km West of Minucciano
28 km North-West · 7 km
6 years ago
20 Nov 2019, 14:45

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).