All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 0 km South of Lamporecchio (PT)

10 years ago · 18 Mar 2016, 05:43

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 69% of Italian events in the past year

Where

0 km South of LamporecchioEarthquakes in the province of PistoiaEarthquakes 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

17 events
Magnitude:lightweakmoderatestrong

The energy released

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

2.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×178 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 ≈ 10 s

Animation sped up ~2× compared to reality.

  • Prato
    19 km from the epicentre
    first tremor in ~3 s
    main shaking in ~6 s
  • Pistoia
    21 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • Firenze
    30 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Lucca
    34 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 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

7 km
shallow

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

in line with the area average (~12 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 (M2.1, 10 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.1
The mainshock
4 km South-East of Castelfiorentino
10 years ago · 20 Feb 2016, 03:40
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
2
last 30 days
12 before4 after
this quake
Strongest of the sequence2.1

How often does it happen here?

about every ~7 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 662 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 · 46 km from here
XCompletely destructive: most buildings are destroyed.
15426.0
Mugello earthquake
13 June 1542 · 46 km from here
IXDestructive: many buildings partly or fully collapse.
17405.6
Garfagnana earthquake
6 March 1740 · 43 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19145.6
Lucchesia earthquake
27 October 1914 · 26 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 32 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

0.7
10 years ago
15 Mar 2016, 14:54
0.9
9 km West of San Marcello Piteglio
27 km North-West · 10 km
10 years ago
15 Mar 2016, 09:42
1.2
3 km South of Montale
17 km North-East · 10 km
10 years ago
13 Mar 2016, 06:53
1.4
3 km South-West of Montale
16 km North-East · 10 km
10 years ago
13 Mar 2016, 05:48
0.9
3 km North of Agliana
16 km North-East · 9 km
10 years ago
13 Mar 2016, 04:48
2.0
10 years ago
24 Mar 2016, 14:29
1.6
1 km East of Capannori
25 km West · 9 km
10 years ago
24 Mar 2016, 14:54
1.6
5 km South-West of Montespertoli
26 km South-East · 9 km
10 years ago
5 Mar 2016, 00:27
1.5
3 km South-East of Castelfiorentino
25 km South-East · 9 km
10 years ago
1 Apr 2016, 22:15
1.7
4 km East of Castelfiorentino
25 km South-East · 10 km
10 years ago
1 Mar 2016, 23:46

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).