All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 5 km East of Lagonegro (PZ)

9 years ago · 11 Apr 2017, 19:22

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 39% of Italian events in the past year

Where

5 km East of LagonegroEarthquakes 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

14 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×708 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 ≈ 26 s

Animation sped up ~5× compared to reality.

  • Potenza
    57 km from the epicentre
    first tremor in ~10 s
    main shaking in ~16 s
  • Corigliano-Rossano
    78 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 s
  • Battipaglia
    89 km from the epicentre
    first tremor in ~15 s
    main shaking in ~26 s
  • Matera
    90 km from the epicentre
    first tremor in ~15 s
    main shaking in ~26 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
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 (~17 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 (M1.8, 9 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.8
The mainshock
3 km South of Sala Consilina
9 years ago · 3 Apr 2017, 13:54
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
12
last 30 days
2 before11 after
this quake
Strongest of the sequence1.8

How often does it happen here?

about every ~14 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 299 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 · 22 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 38 km from here
18365.9
Appennino lucano earthquake
20 November 1836 · 6 km from here
IXDestructive: many buildings partly or fully collapse.
18265.7
Potentino earthquake
1 February 1826 · 42 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

Rimendiello-Mormanno

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

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

1.7
4 km West of Aieta
25 km South · 26 km
9 years ago
12 Apr 2017, 01:14
1.1
9 years ago
16 Apr 2017, 04:02
1.4
9 years ago
16 Apr 2017, 07:46
0.8
9 years ago
16 Apr 2017, 11:08
1.3
9 years ago
16 Apr 2017, 11:08
0.9
4 km East of Castelsaraceno
15 km East · 25 km
9 years ago
16 Apr 2017, 11:55
1.3
9 years ago
16 Apr 2017, 13:49
1.8
3 km South of Sala Consilina
30 km North-West · 18 km
9 years ago
3 Apr 2017, 13:54
0.8
4 km East of Torraca
14 km West · 10 km
9 years ago
23 Apr 2017, 10:30
1.3
2 km West of Paterno
27 km North-West · 9 km
9 years ago
23 Apr 2017, 17:51

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).