All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 4 km East of Castelsaraceno (PZ)

9 years ago · 25 Feb 2017, 16:13

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 63% of Italian events in the past year

Where

4 km East of CastelsaracenoEarthquakes 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.

1.9kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×251 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
    56 km from the epicentre
    first tremor in ~10 s
    main shaking in ~16 s
  • Corigliano-Rossano
    71 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Matera
    77 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 s
  • Altamura
    86 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

9 km
shallow
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 (~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 (M2.4, 9 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.4
The mainshock
2 km North-West of Latronico
9 years ago · 3 Feb 2017, 05:12
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
10
last 30 days
11 before4 after
this quake
Strongest of the sequence2.4

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: 301 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 · 25 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18365.9
Appennino lucano earthquake
20 November 1836 · 21 km from here
IXDestructive: many buildings partly or fully collapse.
18265.7
Potentino earthquake
1 February 1826 · 46 km from here
IXDestructive: many buildings partly or fully collapse.
17085.6
Pollino earthquake
26 January 1708 · 29 km from here
VIII-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 lies about 9 km from Rimendiello-Mormanno, one of the seismic structures mapped by INGV geologists.

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

2.1
4 km West of Castelsaraceno
8 km West · 19 km
9 years ago
21 Feb 2017, 16:14
1.3
9 years ago
21 Feb 2017, 15:31
1.5
4 km South of Grumento Nova
15 km North-West · 10 km
9 years ago
2 Mar 2017, 22:39
0.9
4 km South of Grumento Nova
15 km North-West · 10 km
9 years ago
3 Mar 2017, 03:47
0.9
7 km South of Lauria
23 km South-West · 10 km
9 years ago
3 Mar 2017, 22:33
0.5
9 years ago
16 Feb 2017, 20:11
1.1
3 km West of Rivello
29 km West · 11 km
9 years ago
10 Feb 2017, 07:30
1.3
5 km North-East of Lauria
11 km South-West · 13 km
9 years ago
19 Mar 2017, 04:42
1.7
1 km North-West of Viggianello
22 km South-East · 17 km
9 years ago
3 Feb 2017, 21:08
0.9
3 km South-West of Rivello
30 km West · 13 km
9 years ago
3 Feb 2017, 06:58

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).