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2.4
light
EARTHQUAKE DETAILS

M2.4 earthquake · 6 km West of Castelsaraceno (PZ)

10 years ago · 20 Mar 2016, 14:13

A light earthquake, rarely felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 94% of Italian events in the past year

Where

6 km West 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

18 events
Magnitude:lightweakmoderatestrong

The energy released

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

60kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×7.9 its energy
M1this quakeM3

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 ≈ 27 s

Animation sped up ~5× compared to reality.

  • Potenza
    56 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Corigliano-Rossano
    75 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 s
  • Matera
    85 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 s
  • Altamura
    93 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 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

8 km
shallow

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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 10 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
10
last 30 days
7 before10 after
this quake
Strongest of the sequence2.1

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: 314 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 · 44 km from here
18365.9
Appennino lucano earthquake
20 November 1836 · 12 km from here
IXDestructive: many buildings partly or fully collapse.
18265.7
Potentino earthquake
1 February 1826 · 43 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

1.2
4 km West of Castelsaraceno
2 km East · 10 km
10 years ago
20 Mar 2016, 14:14
1.3
10 years ago
20 Mar 2016, 14:26
1.8
4 km North-East of Nemoli
8 km South-West · 11 km
10 years ago
25 Mar 2016, 17:11
1.6
4 km North-East of Nemoli
8 km South-West · 9 km
10 years ago
25 Mar 2016, 18:51
1.4
5 km North-East of Nemoli
8 km South-West · 10 km
10 years ago
25 Mar 2016, 19:02
1.0
4 km North-East of Nemoli
8 km South-West · 11 km
10 years ago
25 Mar 2016, 20:13
1.0
4 km West of Montemurro
17 km North · 15 km
10 years ago
15 Mar 2016, 01:09
1.0
10 years ago
14 Mar 2016, 18:28
1.2
4 km South-West of Rivello
21 km South-West · 11 km
10 years ago
12 Mar 2016, 21:19
1.9
1 km South-West of Rivello
19 km South-West · 10 km
10 years ago
12 Mar 2016, 07:01

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).