All earthquakes
2.1
light
EARTHQUAKE DETAILS

M2.1 earthquake · 13 km North of Briatico (VV)

4 years ago · 20 Jan 2022, 20:44

A light earthquake, rarely felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 90% of Italian events in the past year

Where

13 km North of BriaticoEarthquakes in the province of Vibo ValentiaEarthquakes in Calabria

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.

21kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×22 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 ≈ 24 s

Animation sped up ~4× compared to reality.

  • Lamezia Terme
    27 km from the epicentre
    first tremor in ~5 s
    main shaking in ~8 s
  • Catanzaro
    49 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Cosenza
    55 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Messina
    83 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 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

6 km
shallow

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

shallower than the area average (~40 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 (M4.3, 4 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

4.3
The mainshock
15 km North of Briatico
4 years ago · 20 Jan 2022, 10:19
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
7
last 30 days
6 before6 after
this quake
Strongest of the sequence4.3

How often does it happen here?

about every ~5 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 849 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.

16387.1
Calabria centrale earthquake
27 March 1638 · 34 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.0
Calabria centrale earthquake
28 March 1783 · 37 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19057.0
Calabria centrale earthquake
8 September 1905 · 3 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17836.7
Calabria centrale earthquake
7 February 1783 · 30 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.

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

The closest seismic structure

Sant'Eufemia

The epicentre lies about 5 km from Sant'Eufemia, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 1 and 12 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

1.2
13 km North-West of Pizzo
2 km East · 6 km
4 years ago
20 Jan 2022, 10:31
4.3
15 km North of Briatico
2 km North · 7 km
4 years ago
20 Jan 2022, 10:19
1.4
15 km South-West of Gizzeria
9 km North · 37 km
4 years ago
15 Jan 2022, 15:47
1.0
2 km North-West of Dinami
30 km South · 11 km
4 years ago
26 Jan 2022, 15:41
1.3
15 km South-West of Gizzeria
6 km North-East · 10 km
4 years ago
14 Jan 2022, 19:13
1.4
2 km North of Dinami
29 km South-East · 5 km
4 years ago
29 Jan 2022, 02:05
2.0
13 km North of Zambrone
7 km West · 49 km
4 years ago
12 Jan 2022, 01:49
1.9
21 km North-West of Tropea
29 km West · 97 km
4 years ago
30 Jan 2022, 22:08
1.3
4 km West of Falerna
21 km North-East · 23 km
4 years ago
29 Dec 2021, 22:39
1.8
2 km West of Zungri
21 km South-West · 48 km
4 years ago
11 Feb 2022, 23:23

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).