All earthquakes
1.2
very light
EARTHQUAKE DETAILS

M1.2 earthquake · 2 km South-East of Brienza (PZ)

8 years ago · 15 Jun 2018, 13:59

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 48% of Italian events in the past year

Where

2 km South-East of BrienzaEarthquakes 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

16 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 ≈ 23 s

Animation sped up ~4× compared to reality.

  • Potenza
    27 km from the epicentre
    first tremor in ~5 s
    main shaking in ~8 s
  • Battipaglia
    57 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Salerno
    73 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Cava de' Tirreni
    81 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 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

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

shallower than 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?

Aftershock

It is an aftershock: it follows a stronger quake (M2.6, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.6
The mainshock
3 km North of Ricigliano
8 years ago · 22 May 2018, 13:29
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
14
last 30 days
8 before7 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: 369 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 · 23 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16946.7
Irpinia-Basilicata earthquake
8 September 1694 · 48 km from here
XCompletely destructive: most buildings are destroyed.
15616.7
Vallo di Diano earthquake
19 August 1561 · 14 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
15616.3
Vallo di Diano earthquake
31 July 1561 · 28 km from here
IX-XCompletely destructive: most buildings are destroyed.

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

1.5
3 km North-East of Picerno
22 km North · 35 km
8 years ago
20 Jun 2018, 05:36
1.6
5 km East of Ruoti
27 km North-East · 22 km
8 years ago
20 Jun 2018, 09:58
2.0
3 km West of Potenza
24 km North-East · 10 km
8 years ago
9 Jun 2018, 19:26
1.5
4 km North of Monte San Giacomo
14 km South-West · 9 km
8 years ago
25 Jun 2018, 21:10
1.0
8 years ago
28 Jun 2018, 02:38
1.4
3 km South-East of Atena Lucana
3 km South-West · 8 km
8 years ago
2 Jun 2018, 23:24
1.5
3 km North-West of Casalbuono
26 km South · 65 km
8 years ago
28 Jun 2018, 19:36
1.8
0 km West of Tramutola
21 km South-East · 11 km
8 years ago
29 Jun 2018, 15:52
1.6
3 km West of Potenza
25 km North-East · 10 km
8 years ago
4 Jul 2018, 15:22
1.2
4 km North of Ricigliano
30 km North-West · 14 km
8 years ago
24 May 2018, 23:01

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).