All earthquakes
1.0
very light
EARTHQUAKE DETAILS

M1.0 earthquake · 3 km West of Padula (SA)

6 years ago · 11 May 2020, 02:42

A very light earthquake, probably not felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 31% of Italian events in the past year

Where

3 km West of PadulaEarthquakes in the province of SalernoEarthquakes in Campania

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.

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 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
    39 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Battipaglia
    63 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Salerno
    80 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 s
  • Cava de' Tirreni
    88 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

18 km
medium depth
2 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

in line with 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?

Foreshock

In hindsight it was a foreshock: 6 years ago the same area had a stronger quake (M2.4). This can only be said after the fact — it was not predictable beforehand.

2.4
The mainshock
3 km North of Sala Consilina
6 years ago · 20 May 2020, 06:39
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
10
last 30 days
5 before10 after
this quake
Strongest of the sequence2.4

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: 350 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 · 19 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
15616.7
Vallo di Diano earthquake
19 August 1561 · 28 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
15616.3
Vallo di Diano earthquake
31 July 1561 · 40 km from here
IX-XCompletely destructive: most buildings are destroyed.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 42 km from here

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

The closest seismic structure

Irpinia-Agri Valley

The epicentre lies about 7 km from Irpinia-Agri Valley, one of the seismic structures mapped by INGV geologists.

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

1.1
2 km West of Padula
1 km East · 14 km
6 years ago
11 May 2020, 02:40
0.8
2 km West of Padula
1 km East · 16 km
6 years ago
11 May 2020, 04:55
0.9
2 km West of Padula
2 km East · 15 km
6 years ago
11 May 2020, 10:57
2.4
6 years ago
20 May 2020, 06:39
1.4
3 km South-West of Sasso di Castalda
15 km North-East · 9 km
6 years ago
1 May 2020, 18:55
1.2
4 km South-East of Paterno
13 km East · 7 km
6 years ago
24 May 2020, 03:04
1.5
3 km East of Padula
6 km East · 11 km
6 years ago
24 May 2020, 09:46
0.8
4 km East of Padula
7 km East · 10 km
6 years ago
24 May 2020, 10:40
0.7
5 km South of Tramutola
16 km East · 11 km
6 years ago
26 Apr 2020, 19:08
1.5
4 km North-East of Tramutola
17 km East · 11 km
6 years ago
21 Apr 2020, 01:51

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).