All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 3 km West of San Pietro di Caridà (RC)

7 years ago · 21 Sept 2019, 23:51

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 West of San Pietro di CaridàEarthquakes in the province of Reggio CalabriaEarthquakes 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

12 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 ≈ 19 s

Animation sped up ~4× compared to reality.

  • Lamezia Terme
    53 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Reggio di Calabria
    57 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Catanzaro
    59 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • Messina
    65 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 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

19 km
medium depth
2.1 times the height of Mount Everest

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

in line with the area average (~21 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: 7 years ago the same area had a stronger quake (M1.8). This can only be said after the fact — it was not predictable beforehand.

1.8
The mainshock
4 km West of San Pietro di Caridà
7 years ago · 24 Sept 2019, 13:37
Activity in the area right now (30 km radius)
1
last 24 hours
3
last 7 days
6
last 30 days
2 before9 after
this quake
Strongest of the sequence1.8

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: 507 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 · 27 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.0
Calabria centrale earthquake
28 March 1783 · 42 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19057.0
Calabria centrale earthquake
8 September 1905 · 37 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17836.7
Calabria centrale earthquake
7 February 1783 · 11 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

Serre

The epicentre sits above this source area: the deep structure where this area's earthquakes can originate.

estimated maximum magnitude 7.2between 3 and 11 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 Galatro
2 km South · 17 km
7 years ago
23 Sept 2019, 01:51
1.6
7 years ago
23 Sept 2019, 12:15
1.8
7 years ago
24 Sept 2019, 13:37
1.6
4 km West of Gioia Tauro
25 km West · 16 km
7 years ago
24 Sept 2019, 14:42
1.7
4 km West of Gioia Tauro
24 km West · 11 km
7 years ago
24 Sept 2019, 14:47
1.5
4 km West of Gioia Tauro
25 km West · 14 km
7 years ago
24 Sept 2019, 14:49
1.5
4 km North of Palmi
25 km West · 17 km
7 years ago
24 Sept 2019, 15:03
1.7
7 years ago
25 Sept 2019, 23:59
1.5
7 years ago
17 Sept 2019, 22:07
1.8
6 km West of Joppolo
30 km West · 10 km
7 years ago
30 Sept 2019, 10:15

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).