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2.7
light
EARTHQUAKE DETAILS

M2.7 earthquake · 1 km South of Roccabernarda (KR)

3 years ago · 22 Aug 2023, 23:25

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

Stronger than 97% of Italian events in the past year

Where

1 km South of RoccabernardaEarthquakes in the province of CrotoneEarthquakes in Calabria

How far away could it be felt?

An estimate of how far people may have felt this quake.

  • up to ~2 km · felt only by some, at rest
    ≈ 3,000 people live in this area

The coloured rings on the map below show these distances.

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.

169kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×2.8 its energy
M2this quakeM4

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 ≈ 17 s

Animation sped up ~3× compared to reality.

  • Crotone
    17 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Catanzaro
    32 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Lamezia Terme
    55 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Cosenza
    59 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 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

8 km
shallow

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

shallower than the area average (~18 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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 8 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
2
last 30 days
4 before8 after
this quake
Strongest of the sequence1.5

How often does it happen here?

about every ~19 days

Within 50 km of this epicentre, a magnitude ≥ 2.5 earthquake has occurred on average this often: 229 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.

17837.0
Calabria centrale earthquake
28 March 1783 · 49 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16386.8
Crotonese earthquake
8 June 1638 · 25 km from here
XCompletely destructive: most buildings are destroyed.
18326.7
Crotonese earthquake
8 March 1832 · 2 km from here
XCompletely destructive: most buildings are destroyed.
16266.1
Calabria centrale earthquake
4 April 1626 · 45 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

Crotone-Rossano

The epicentre lies about 18 km from Crotone-Rossano, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.3between 3 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

1.1
4 km West of Cutro
8 km South · 16 km
3 years ago
28 Aug 2023, 08:41
1.3
2 km West of Zagarise
22 km West · 8 km
3 years ago
1 Sept 2023, 19:47
1.2
4 km North of Albi
26 km West · 9 km
3 years ago
5 Aug 2023, 21:29
0.8
2 km South of Taverna
27 km West · 4 km
3 years ago
1 Aug 2023, 03:16
1.5
4 km South-East of Taverna
26 km West · 7 km
3 years ago
1 Aug 2023, 02:52
1.5
3 km South of Taverna
27 km West · 7 km
3 years ago
17 Sept 2023, 06:08
1.2
4 km South-East of Taverna
26 km West · 8 km
3 years ago
17 Sept 2023, 11:28
1.5
3 km South-East of Taverna
26 km West · 5 km
3 years ago
17 Sept 2023, 11:47
1.4
3 km South-East of Taverna
26 km West · 5 km
3 years ago
17 Sept 2023, 11:47
1.2
3 km South-East of Taverna
26 km West · 8 km
3 years ago
17 Sept 2023, 13:45

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).