All earthquakes
0.9
very light
EARTHQUAKE DETAILS

M0.9 earthquake · 5 km South-West of Luzzi (CS)

3 years ago · 20 Jun 2023, 15:51

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 23% of Italian events in the past year

Where

5 km South-West of LuzziEarthquakes in the province of CosenzaEarthquakes in Calabria

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

24 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,413 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 ≈ 19 s

Animation sped up ~3× compared to reality.

  • Cosenza
    15 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Corigliano-Rossano
    28 km from the epicentre
    first tremor in ~5 s
    main shaking in ~8 s
  • Lamezia Terme
    50 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Catanzaro
    64 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 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.

shallower than the area average (~20 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: 3 years ago the same area had a stronger quake (M2.0). This can only be said after the fact — it was not predictable beforehand.

2.0
The mainshock
5 km East of Pietrafitta
3 years ago · 14 Jul 2023, 06:35
Activity in the area right now (30 km radius)
0
last 24 hours
4
last 7 days
18
last 30 days
10 before13 after
this quake
Strongest of the sequence2.0

How often does it happen here?

about every ~9 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 500 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.

16387.1
Calabria centrale earthquake
27 March 1638 · 40 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16386.8
Crotonese earthquake
8 June 1638 · 49 km from here
XCompletely destructive: most buildings are destroyed.
11846.8
Valle del Crati earthquake
24 May 1184 · 6 km from here
IXDestructive: many buildings partly or fully collapse.
18546.3
Cosentino earthquake
12 February 1854 · 17 km from here
XCompletely destructive: most buildings are destroyed.

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

The closest seismic structure

Crati Valley

The epicentre sits above this source area: the deep structure where this area's earthquakes can originate.

estimated maximum magnitude 6.6between 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
4 km North-West of Grimaldi
28 km South · 9 km
3 years ago
20 Jun 2023, 12:28
1.2
6 km North-West of Aprigliano
21 km South-East · 12 km
3 years ago
17 Jun 2023, 22:52
1.2
3 years ago
23 Jun 2023, 20:11
1.2
3 km North-West of Mongrassano
21 km North-West · 12 km
3 years ago
24 Jun 2023, 06:53
1.0
1 km East of Rovito
12 km South-East · 11 km
3 years ago
16 Jun 2023, 20:37
1.1
3 years ago
28 Jun 2023, 03:31
1.2
2 km West of Rota Greca
18 km West · 42 km
3 years ago
28 Jun 2023, 05:14
1.0
4 km North-East of Aprigliano
28 km South-East · 20 km
3 years ago
11 Jun 2023, 11:35
1.6
3 km East of Rende
8 km South · 10 km
3 years ago
9 Jun 2023, 01:52
0.7
6 km North-West of Acri
17 km North-East · 10 km
3 years ago
7 Jun 2023, 03:03

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).