All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 8 km North-East of Salandra (MT)

6 years ago · 7 Aug 2020, 15:07

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

8 km North-East of SalandraEarthquakes in the province of MateraEarthquakes 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

13 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 ≈ 17 s

Animation sped up ~3× compared to reality.

  • Matera
    24 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 s
  • Altamura
    33 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Potenza
    51 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Bitonto
    57 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 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 (M2.7, 6 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.7
The mainshock
2 km North-East of Cirigliano
6 years ago · 5 Aug 2020, 07:24
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
4
last 30 days
8 before4 after
this quake
Strongest of the sequence2.7

How often does it happen here?

about every ~29 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 147 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.

19175.5
Val d'Agri earthquake
13 October 1917 · 50 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
18575.3
Basilicata earthquake
26 December 1857 · 46 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18465.2
Potentino earthquake
8 August 1846 · 23 km from here
VI-VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
18855.1
Basilicata earthquake
24 December 1885 · 5 km from here
VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.

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

The closest seismic structure

Baragiano-Palagianello

The epicentre lies about 9 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

1.5
8 km East of Salandra
1 km South-East · 11 km
6 years ago
7 Aug 2020, 18:37
1.7
8 km East of Matera
29 km East · 1 km
6 years ago
5 Aug 2020, 09:47
2.7
2 km North-East of Cirigliano
24 km South-West · 19 km
6 years ago
5 Aug 2020, 07:24
1.0
6 km South of Irsina
18 km North-West · 27 km
6 years ago
31 Jul 2020, 00:32
1.6
3 km South of Montescaglioso
26 km South-East · 10 km
6 years ago
22 Jul 2020, 02:15
2.7
5 km North-West of Bernalda
30 km South-East · 7 km
6 years ago
22 Jul 2020, 02:14
1.8
3 km East of Stigliano
23 km South · 19 km
6 years ago
21 Jul 2020, 00:34
1.8
4 km North-East of Stigliano
22 km South · 18 km
6 years ago
21 Jul 2020, 00:31
1.9
4 km North-East of Stigliano
22 km South · 22 km
6 years ago
27 Aug 2020, 17:18
1.0
4 km North-East of Stigliano
22 km South · 19 km
6 years ago
29 Aug 2020, 03:13

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).