All earthquakes
0.6
very light
EARTHQUAKE DETAILS

M0.6 earthquake · 3 km South-West of Grumento Nova (PZ)

3 years ago · 27 May 2023, 12:54

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 7% of Italian events in the past year

Where

3 km South-West of Grumento NovaEarthquakes in the province of PotenzaEarthquakes in Basilicata

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

45 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 ≈ 25 s

Animation sped up ~5× compared to reality.

  • Potenza
    43 km from the epicentre
    first tremor in ~7 s
    main shaking in ~13 s
  • Matera
    80 km from the epicentre
    first tremor in ~13 s
    main shaking in ~23 s
  • Battipaglia
    85 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 s
  • Altamura
    86 km from the epicentre
    first tremor in ~14 s
    main shaking in ~25 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 (~16 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 (M2.7, 3 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.7
The mainshock
2 km North-West of Lauria
3 years ago · 12 May 2023, 03:02
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
10
last 30 days
19 before25 after
this quake
Strongest of the sequence2.7

How often does it happen here?

about every ~13 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 326 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.

18577.1
Basilicata earthquake
16 December 1857 · 9 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
15616.7
Vallo di Diano earthquake
19 August 1561 · 44 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 48 km from here
18365.9
Appennino lucano earthquake
20 November 1836 · 16 km from here
IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Irpinia-Agri Valley

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

estimated maximum magnitude 6.8between 1 and 14 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

1.0
1 km South-East of Sarconi
7 km South-East · 9 km
3 years ago
27 May 2023, 11:45
1.3
1 km East of Sarconi
7 km South-East · 9 km
3 years ago
27 May 2023, 10:23
1.4
0 km South-East of Sarconi
7 km South-East · 8 km
3 years ago
27 May 2023, 10:15
0.9
4 km South-East of Sarconi
11 km South-East · 9 km
3 years ago
28 May 2023, 02:19
1.0
4 km West of Castelsaraceno
11 km South-East · 10 km
3 years ago
28 May 2023, 02:55
0.7
3 km North-West of Sanza
30 km West · 21 km
3 years ago
26 May 2023, 20:12
1.1
2 km South-East of Latronico
26 km South-East · 11 km
3 years ago
28 May 2023, 08:21
0.8
4 km North-West of Sarconi
3 km South-East · 9 km
3 years ago
29 May 2023, 00:45
0.5
3 km South-West of Sarconi
8 km South-East · 10 km
3 years ago
25 May 2023, 03:38
1.6
5 km North-East of Castelsaraceno
14 km South-East · 10 km
3 years ago
22 May 2023, 12:56

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).