All earthquakes
1.2
very light
EARTHQUAKE DETAILS

M1.2 earthquake · 3 km South-West of Viticuso (FR)

6 years ago · 21 Jul 2020, 07:32

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 48% of Italian events in the past year

Where

3 km South-West of ViticusoEarthquakes in the province of FrosinoneEarthquakes in Lazio

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

15 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.0kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×501 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 ≈ 20 s

Animation sped up ~4× compared to reality.

  • Caserta
    52 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Aversa
    63 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Giugliano in Campania
    66 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Acerra
    69 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 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

7 km
shallow

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

in line with the area average (~12 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 (M2.0). This can only be said after the fact — it was not predictable beforehand.

2.0
The mainshock
4 km East of Vallerotonda
6 years ago · 8 Aug 2020, 00:55
Activity in the area right now (30 km radius)
0
last 24 hours
9
last 7 days
14
last 30 days
2 before12 after
this quake
Strongest of the sequence2.0

How often does it happen here?

about every ~11 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 388 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.

13496.8
Lazio-Molise earthquake
9 September 1349 · 5 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18056.7
Molise earthquake
26 July 1805 · 43 km from here
XCompletely destructive: most buildings are destroyed.
16546.3
Sorano earthquake
24 July 1654 · 27 km from here
XCompletely destructive: most buildings are destroyed.
19845.9
Monti della Meta earthquake
7 May 1984 · 19 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Venafro

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

estimated maximum magnitude 6.6between 1 and 13 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

1.6
3 km West of Viticuso
0 km North · 8 km
6 years ago
20 Jul 2020, 01:27
0.4
2 km North-East of Vicalvi
28 km North-West · 5 km
6 years ago
15 Jul 2020, 22:13
1.3
2 km South-West of Pesche
28 km East · 10 km
6 years ago
5 Aug 2020, 03:22
1.8
4 km East of Vallerotonda
9 km North · 7 km
6 years ago
7 Aug 2020, 14:19
2.0
4 km East of Vallerotonda
9 km North · 8 km
6 years ago
8 Aug 2020, 00:55
1.3
2 km West of Pozzilli
6 km East · 15 km
6 years ago
11 Aug 2020, 14:29
1.9
6 years ago
11 Aug 2020, 15:25
1.7
1 km South of Conca Casale
5 km South-East · 11 km
6 years ago
11 Aug 2020, 16:56
0.5
5 km North of Settefrati
25 km North-West · 14 km
6 years ago
15 Aug 2020, 05:15
1.3
3 km West of Scapoli
11 km North-East · 8 km
6 years ago
15 Aug 2020, 06:10

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).