All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 3 km North-East of Cusano Mutri (BN)

5 years ago · 19 Mar 2021, 16:48

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 69% of Italian events in the past year

Where

3 km North-East of Cusano MutriEarthquakes in the province of BeneventoEarthquakes 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

31 events
Magnitude:lightweakmoderatestrong

The energy released

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

2.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×178 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 ≈ 15 s

Animation sped up ~3× compared to reality.

  • Benevento
    33 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Caserta
    35 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Acerra
    47 km from the epicentre
    first tremor in ~8 s
    main shaking in ~13 s
  • Aversa
    52 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

2 km
shallow

At only a few km deep the shaking is felt more sharply at the surface.

shallower than the area average (~14 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: 5 years ago the same area had a stronger quake (M2.6). This can only be said after the fact — it was not predictable beforehand.

2.6
The mainshock
4 km South-West of Sassinoro
5 years ago · 21 Mar 2021, 09:32
Activity in the area right now (30 km radius)
0
last 24 hours
6
last 7 days
9
last 30 days
26 before4 after
this quake
Strongest of the sequence2.6

How often does it happen here?

about every ~8 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 545 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.

14567.2
Appennino centro-meridionale earthquake
5 December 1456 · 17 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16887.1
Sannio earthquake
5 June 1688 · 11 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18056.7
Molise earthquake
26 July 1805 · 15 km from here
XCompletely destructive: most buildings are destroyed.
17026.6
Sannio-Irpinia earthquake
14 March 1702 · 48 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

Miranda-Apice

The epicentre lies about 2 km from Miranda-Apice, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 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

1.8
4 km East of Campobasso
27 km North-East · 22 km
5 years ago
19 Mar 2021, 17:24
0.9
4 km South-East of Pietraroja
8 km South-East · 8 km
5 years ago
18 Mar 2021, 23:19
1.0
3 km West of Riccia
27 km East · 10 km
5 years ago
18 Mar 2021, 20:09
2.2
4 km East of Pietraroja
8 km South-East · 9 km
5 years ago
20 Mar 2021, 20:43
2.6
5 years ago
21 Mar 2021, 09:32
1.1
0 km South of Sassinoro
10 km East · 11 km
5 years ago
16 Mar 2021, 01:55
1.8
4 km South-West of Campochiaro
6 km North-West · 8 km
5 years ago
7 Mar 2021, 21:27
1.1
5 years ago
6 Mar 2021, 06:12
1.5
4 km West of San Polo Matese
10 km North-West · 1 km
5 years ago
5 Mar 2021, 16:30
1.9
1 km North-West of Cusano Mutri
3 km South-West · 5 km
5 years ago
4 Mar 2021, 03:54

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).