All earthquakes
1.2
very light
EARTHQUAKE DETAILS

4 km West of Ruoti

23 days ago · 2 Aug, 19:47

A very light earthquake, probably not felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 47% of Italian events in the past year

Where

4 km West of RuotiEarthquakes 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

21 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 ≈ 20 s

Animation sped up ~4× compared to reality.

  • Potenza
    14 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Battipaglia
    60 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Cerignola
    64 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Andria
    70 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 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

10 km
medium depth
1.1 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

in line with 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?

Foreshock

In hindsight it was a foreshock: 14 days ago the same area had a stronger quake (M2.1). This can only be said after the fact — it was not predictable beforehand.

2.1
The mainshock
4 km West of Abriola
14 days ago · 11 Aug, 11:49
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
17
last 30 days
8 before12 after
nowthis quake
Strongest of the sequence2.1

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: 345 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 · 42 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19806.8
Irpinia-Basilicata earthquake
23 November 1980 · 35 km from here
XCompletely destructive: most buildings are destroyed.
16946.7
Irpinia-Basilicata earthquake
8 September 1694 · 27 km from here
XCompletely destructive: most buildings are destroyed.
15616.7
Vallo di Diano earthquake
19 August 1561 · 20 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.

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

The closest seismic structure

Baragiano-Palagianello

The epicentre lies about 1 km from Baragiano-Palagianello, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.4between 13 and 22 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

1.9
2 km East of Potenza
16 km East · 11 km
22 days ago
3 Aug, 14:49
1.2
3 km West of Pignola
17 km South-East · 14 km
24 days ago
1 Aug, 14:46
0.8
7 km East of Sasso di Castalda
27 km South-East · 15 km
21 days ago
4 Aug, 17:46
0.6
25 days ago
31 Jul, 19:29
1.2
2 km North of Forenza
25 km North-East · 3 km
20 days ago
5 Aug, 11:19
1.3
25 days ago
31 Jul, 03:00
1.7
4 km South of Maschito
28 km North-East · 13 km
19 days ago
6 Aug, 01:07
1.5
4 km East of Ruoti
8 km East · 11 km
19 days ago
6 Aug, 04:51
1.0
0 km North of Abriola
23 km South-East · 10 km
27 days ago
29 Jul, 21:31
1.0
4 km North of Colliano
28 km West · 18 km
16 days ago
9 Aug, 18:14

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).

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