All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 3 km East of Anzano di Puglia (FG)

6 years ago · 23 Jul 2020, 20:51

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

Stronger than 63% of Italian events in the past year

Where

3 km East of Anzano di PugliaEarthquakes in the province of FoggiaEarthquakes in Puglia

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

61 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 ≈ 15 s

Animation sped up ~3× compared to reality.

  • Benevento
    45 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Foggia
    45 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Cerignola
    47 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Avellino
    49 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 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

21 km
medium depth
2.4 times the height of Mount Everest

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

deeper than the area average (~13 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 (M3.0, 6 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.0
The mainshock
3 km North-West of Sant'Angelo dei Lombardi
6 years ago · 3 Jul 2020, 18:19
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
7
last 30 days
89 before4 after
this quake
Strongest of the sequence3.0

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: 368 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.

19806.8
Irpinia-Basilicata earthquake
23 November 1980 · 30 km from here
XCompletely destructive: most buildings are destroyed.
17326.8
Irpinia earthquake
29 November 1732 · 22 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16946.7
Irpinia-Basilicata earthquake
8 September 1694 · 29 km from here
XCompletely destructive: most buildings are destroyed.
19306.7
Irpinia earthquake
23 July 1930 · 5 km from here
XCompletely destructive: most buildings are destroyed.

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

The closest seismic structure

Mirabella Eclano-Monteverde

The epicentre lies about 4 km from Mirabella Eclano-Monteverde, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 1 and 16 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
4 km South-West of Accadia
5 km North · 21 km
6 years ago
25 Jul 2020, 00:19
1.6
1 km South-East of Melfi
28 km East · 10 km
6 years ago
27 Jul 2020, 11:46
1.0
6 years ago
11 Jul 2020, 00:45
0.8
6 years ago
10 Jul 2020, 07:16
0.9
4 km South of Rocca San Felice
24 km South-West · 11 km
6 years ago
10 Jul 2020, 07:09
1.1
4 km South of Rocca San Felice
24 km South-West · 13 km
6 years ago
10 Jul 2020, 07:08
1.8
6 years ago
10 Jul 2020, 07:07
2.1
6 years ago
10 Jul 2020, 07:07
1.3
6 years ago
6 Jul 2020, 21:05
1.5
6 years ago
6 Jul 2020, 18:55

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).