All earthquakes
0.6
very light
EARTHQUAKE DETAILS

M0.6 earthquake · 5 km South-East of Campi Bisenzio (FI)

5 years ago · 27 Jun 2021, 10:31

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

Stronger than 7% of Italian events in the past year

Where

5 km South-East of Campi BisenzioEarthquakes in the province of FirenzeEarthquakes 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

10 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.1kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×3,981 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 ≈ 16 s

Animation sped up ~3× compared to reality.

  • Firenze
    5 km from the epicentre
    first tremor in ~2 s
    main shaking in ~3 s
  • Prato
    13 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Pistoia
    32 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Siena
    56 km from the epicentre
    first tremor in ~10 s
    main shaking in ~16 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

11 km
medium depth
1.2 times the height of Mount Everest

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

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?

Aftershock

It is an aftershock: it follows a stronger quake (M2.8, 5 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.8
The mainshock
4 km East of Certaldo
5 years ago · 7 Jun 2021, 16:58
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
3
last 30 days
5 before4 after
this quake
Strongest of the sequence2.8

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: 615 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.

19196.4
Mugello earthquake
29 June 1919 · 31 km from here
XCompletely destructive: most buildings are destroyed.
15426.0
Mugello earthquake
13 June 1542 · 29 km from here
IXDestructive: many buildings partly or fully collapse.
15586.0
Valdarno superiore earthquake
13 April 1558 · 48 km from here
IXDestructive: many buildings partly or fully collapse.
19145.6
Lucchesia earthquake
27 October 1914 · 49 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

Mugello-Citta' di Castello-Leonessa

The epicentre lies about 22 km from Mugello-Citta' di Castello-Leonessa, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 1 and 8 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

0.4
3 km East of Barberino di Mugello
28 km North-East · 7 km
5 years ago
27 Jun 2021, 19:21
1.2
3 km East of Barberino di Mugello
28 km North-East · 9 km
5 years ago
28 Jun 2021, 03:17
1.7
5 years ago
10 Jul 2021, 17:34
1.7
5 years ago
10 Jul 2021, 17:34
1.2
5 years ago
13 Jun 2021, 03:34
2.8
4 km East of Certaldo
24 km South · 8 km
5 years ago
7 Jun 2021, 16:58
1.8
5 years ago
29 May 2021, 08:44
1.2
5 years ago
29 May 2021, 00:28
1.4
5 years ago
28 May 2021, 23:59

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).