All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 5 km North-East of Comano (MS)

5 years ago · 29 Sept 2021, 19:34

A very light earthquake, probably not felt by people. Being deep, it is felt less at the surface.

Stronger than 69% of Italian events in the past year

Where

5 km North-East of ComanoEarthquakes in the province of Massa-CarraraEarthquakes 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

12 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 ≈ 22 s

Animation sped up ~4× compared to reality.

  • Carrara
    30 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Massa
    33 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • La Spezia
    39 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Parma
    50 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 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

58 km
deep
6.5 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~15 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, 5 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.1
The mainshock
5 km North-West of Piazza al Serchio
5 years ago · 2 Sept 2021, 15:22
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
7
last 30 days
4 before7 after
this quake
Strongest of the sequence2.1

How often does it happen here?

about every ~4 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 1087 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 · 21 km from here
XCompletely destructive: most buildings are destroyed.
18346.0
Val di Taro-Lunigiana earthquake
14 February 1834 · 26 km from here
IXDestructive: many buildings partly or fully collapse.
18375.9
Lunigiana earthquake
11 April 1837 · 20 km from here
XCompletely destructive: most buildings are destroyed.
17405.6
Garfagnana earthquake
6 March 1740 · 40 km from here
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

Garfagnana

The epicentre lies about 11 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

1.6
5 years ago
5 Oct 2021, 13:43
1.2
4 km East of Calice al Cornoviglio
25 km South-West · 10 km
5 years ago
7 Oct 2021, 02:31
1.7
4 km North-East of Comano
2 km South-West · 15 km
5 years ago
7 Oct 2021, 05:22
2.0
3 km North of Corniglio
17 km North-West · 19 km
5 years ago
20 Sept 2021, 16:47
1.3
1 km West of Santo Stefano di Magra
30 km South-West · 11 km
5 years ago
11 Oct 2021, 00:56
1.1
3 km North of Minucciano
18 km South · 10 km
5 years ago
13 Oct 2021, 01:54
0.6
5 km South of Licciana Nardi
16 km South-West · 11 km
5 years ago
4 Sept 2021, 09:56
0.9
5 km South of Licciana Nardi
16 km South-West · 11 km
5 years ago
4 Sept 2021, 09:24
1.9
4 years ago
26 Oct 2021, 17:17
0.9
4 years ago
26 Oct 2021, 20:44

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).