All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 2 km South of Lajatico (PI)

6 years ago · 6 Dec 2019, 02:54

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

Stronger than 63% of Italian events in the past year

Where

2 km South of LajaticoEarthquakes in the province of PisaEarthquakes 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

11 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.9kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×251 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 ≈ 15 s

Animation sped up ~3× compared to reality.

  • Pisa
    41 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Livorno
    47 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Siena
    50 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Lucca
    51 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 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

12 km
medium depth
1.3 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?

Foreshock

In hindsight it was a foreshock: 6 years ago the same area had a stronger quake (M1.5). This can only be said after the fact — it was not predictable beforehand.

1.5
The mainshock
3 km North of Colle di Val d'Elsa
6 years ago · 4 Jan 2020, 04:27
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
2
last 30 days
5 before5 after
this quake
Strongest of the sequence1.5

How often does it happen here?

about every ~14 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 301 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.

18466.0
Colline Pisane earthquake
14 August 1846 · 14 km from here
XCompletely destructive: most buildings are destroyed.
14145.7
Colline Metallifere earthquake
7 August 1414 · 37 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18125.2
Val di Pesa earthquake
11 September 1812 · 42 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18715.2
Val di Cecina earthquake
29 July 1871 · 17 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Livorno Hills

The epicentre lies about 15 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

1.1
6 years ago
7 Dec 2019, 21:20
1.4
6 years ago
29 Nov 2019, 19:10
1.2
2 km South-East of Castelfiorentino
27 km North-East · 5 km
6 years ago
22 Nov 2019, 18:43
0.9
6 years ago
21 Nov 2019, 02:49
1.1
6 years ago
16 Nov 2019, 01:24
1.4
6 years ago
28 Dec 2019, 12:35
1.0
6 years ago
28 Dec 2019, 17:21
1.3
4 km South-East of Pomarance
25 km South-East · 7 km
6 years ago
31 Dec 2019, 01:58
1.4
6 years ago
10 Nov 2019, 18:00
1.5
6 years ago
4 Jan 2020, 04:27

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).