All earthquakes
1.2
very light
EARTHQUAKE DETAILS

1 km South-West of Grisolia

137 months ago · 23 May, 22:24

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 47% of Italian events in the past year

Where

1 km South-West of GrisoliaEarthquakes 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

40 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.0kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×501 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 ≈ 30 s

Animation sped up ~6× compared to reality.

  • Corigliano-Rossano
    48 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Cosenza
    59 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Lamezia Terme
    91 km from the epicentre
    first tremor in ~15 s
    main shaking in ~26 s
  • Potenza
    105 km from the epicentre
    first tremor in ~18 s
    main shaking in ~30 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

9 km
shallow
1.1 times the height of Mount Everest

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

shallower than the area average (~30 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 (M3.3, 137 months ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.3
The mainshock
21 km West of Diamante
137 months ago · 21 May, 05:05
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
5
last 30 days
18 before21 after
this quake
Strongest of the sequence3.3

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: 453 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.

11846.8
Valle del Crati earthquake
24 May 1184 · 45 km from here
IXDestructive: many buildings partly or fully collapse.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 47 km from here
18365.9
Appennino lucano earthquake
20 November 1836 · 48 km from here
IXDestructive: many buildings partly or fully collapse.
19135.6
Calabria settentrionale earthquake
28 June 1913 · 37 km from here
VIII-IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Rimendiello-Mormanno

The epicentre lies about 18 km from Rimendiello-Mormanno, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.6between 1 and 12 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

3.3
21 km West of Diamante
27 km West · 288 km
137 months ago
21 May, 05:05
1.0
4 km East of Mormanno
22 km North-East · 9 km
137 months ago
19 May, 23:26
0.8
4 km North-East of Morano Calabro
29 km North-East · 10 km
137 months ago
19 May, 04:40
1.6
3 km North of Orsomarso
12 km North-East · 49 km
137 months ago
30 May, 02:19
0.8
3 km East of Mormanno
21 km North-East · 7 km
137 months ago
31 May, 07:09
0.8
6 km South-East of Laino Castello
24 km North-East · 8 km
137 months ago
31 May, 08:04
1.1
5 km North of Morano Calabro
28 km North-East · 9 km
137 months ago
15 May, 23:25
1.5
5 km West of Rotonda
28 km North-East · 8 km
137 months ago
31 May, 23:20
1.8
5 km West of Rotonda
27 km North-East · 8 km
137 months ago
31 May, 23:21
1.7
4 km North of Morano Calabro
27 km North-East · 8 km
138 months ago
14 May, 13:02

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).

We use cookies to analyse site traffic and improve your experience.

Privacy PolicyCookie Policy