All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 3 km North-West of Stefanaconi (VV)

2 years ago · 29 Oct 2023, 04:33

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

Stronger than 69% of Italian events in the past year

Where

3 km North-West of StefanaconiEarthquakes 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

10 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • Lamezia Terme
    34 km from the epicentre
    first tremor in ~6 s
    main shaking in ~11 s
  • Catanzaro
    48 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Cosenza
    68 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Reggio di Calabria
    73 km from the epicentre
    first tremor in ~13 s
    main shaking in ~21 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

18 km
medium depth
2 times the height of Mount Everest

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

shallower than the area average (~31 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 (M1.8, 2 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.8
The mainshock
3 km North-East of Arena
2 years ago · 15 Oct 2023, 07:45
Activity in the area right now (30 km radius)
1
last 24 hours
1
last 7 days
7
last 30 days
7 before2 after
this quake
Strongest of the sequence1.8

How often does it happen here?

about every ~6 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 726 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.

17837.1
Calabria meridionale earthquake
5 February 1783 · 44 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16387.1
Calabria centrale earthquake
27 March 1638 · 44 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.0
Calabria centrale earthquake
28 March 1783 · 32 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19057.0
Calabria centrale earthquake
8 September 1905 · 19 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 sits above this source area: the deep structure where this area's earthquakes can originate.

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

1.5
2 years ago
23 Oct 2023, 03:12
1.4
1 km East of San Ferdinando
27 km South-West · 11 km
2 years ago
22 Oct 2023, 14:32
1.8
3 km North-East of Arena
18 km South-East · 11 km
2 years ago
15 Oct 2023, 07:45
1.6
3 km North-East of Arena
18 km South-East · 10 km
2 years ago
15 Oct 2023, 04:41
1.3
3 km South-East of Jacurso
26 km North-East · 38 km
3 years ago
9 Oct 2023, 17:04
1.6
2 km South-East of Jacurso
26 km North-East · 35 km
3 years ago
9 Oct 2023, 16:25
1.4
2 km West of Amaroni
28 km East · 37 km
3 years ago
9 Oct 2023, 16:18
1.5
2 km West of Acquaro
17 km South-East · 12 km
2 years ago
18 Nov 2023, 23:30
1.0
1 km North-West of Girifalco
30 km North-East · 11 km
2 years ago
19 Nov 2023, 04:12

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).