All earthquakes
1.0
very light
EARTHQUAKE DETAILS

M1.0 earthquake · 4 km West of Tramutola (PZ)

3 years ago · 8 Aug 2023, 16:47

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 31% of Italian events in the past year

Where

4 km West of TramutolaEarthquakes 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

61 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 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
    37 km from the epicentre
    first tremor in ~6 s
    main shaking in ~11 s
  • Battipaglia
    72 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Matera
    84 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 s
  • Altamura
    89 km from the epicentre
    first tremor in ~15 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

7 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?

Foreshock

In hindsight it was a foreshock: 3 years ago the same area had a stronger quake (M2.6). This can only be said after the fact — it was not predictable beforehand.

2.6
The mainshock
5 km South of Sarconi
3 years ago · 1 Sept 2023, 21:47
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
15
last 30 days
49 before50 after
this quake
Strongest of the sequence2.6

How often does it happen here?

about every ~12 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 347 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 · 33 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
15616.3
Vallo di Diano earthquake
31 July 1561 · 46 km from here
IX-XCompletely destructive: most buildings are destroyed.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 46 km from here

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
5 km South of Sarconi
22 km South-East · 10 km
3 years ago
10 Aug 2023, 02:02
0.7
2 km South of Paterno
3 km North · 8 km
3 years ago
10 Aug 2023, 11:36
1.2
3 km North of Casaletto Spartano
22 km South-West · 14 km
3 years ago
11 Aug 2023, 15:54
0.6
4 km South-West of Grumento Nova
13 km South-East · 9 km
3 years ago
13 Aug 2023, 05:00
1.1
3 km North-East of Moliterno
15 km South-East · 10 km
3 years ago
3 Aug 2023, 23:43
1.0
2 km North-West of Anzi
26 km North-East · 19 km
3 years ago
13 Aug 2023, 14:34
1.7
1 km North-East of Anzi
27 km North-East · 22 km
3 years ago
13 Aug 2023, 14:42
0.7
3 years ago
3 Aug 2023, 15:55
1.1
4 km North-East of Moliterno
15 km South-East · 9 km
3 years ago
2 Aug 2023, 09:10
1.1
4 km North of Moliterno
13 km South-East · 9 km
3 years ago
16 Aug 2023, 02:53

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).