All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 2 km South-West of Serrastretta (CZ)

3 years ago · 28 Aug 2023, 17:17

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

Stronger than 63% of Italian events in the past year

Where

2 km South-West of SerrastrettaEarthquakes in the province of CatanzaroEarthquakes 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

30 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.9kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×251 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 ≈ 19 s

Animation sped up ~3× compared to reality.

  • Lamezia Terme
    9 km from the epicentre
    first tremor in ~3 s
    main shaking in ~6 s
  • Catanzaro
    21 km from the epicentre
    first tremor in ~5 s
    main shaking in ~8 s
  • Cosenza
    35 km from the epicentre
    first tremor in ~7 s
    main shaking in ~11 s
  • Crotone
    63 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

17 km
medium depth
2 times the height of Mount Everest

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

in line with the area average (~16 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: 3 years ago the same area had a stronger quake (M2.9). This can only be said after the fact — it was not predictable beforehand.

2.9
The mainshock
2 km North-West of Aprigliano
3 years ago · 9 Sept 2023, 23:15
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
28
last 30 days
4 before25 after
this quake
Strongest of the sequence2.9

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: 526 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 · 12 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.0
Calabria centrale earthquake
28 March 1783 · 22 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19057.0
Calabria centrale earthquake
8 September 1905 · 38 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
11846.8
Valle del Crati earthquake
24 May 1184 · 50 km from here
IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Savuto Valley

The epicentre lies about 5 km from Savuto Valley, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 2 and 14 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

1.7
1 km West of Serrastretta
1 km North · 19 km
3 years ago
28 Aug 2023, 17:18
1.4
2 km West of Serrastretta
1 km North · 19 km
3 years ago
28 Aug 2023, 17:21
0.8
3 km West of Aprigliano
28 km North · 13 km
3 years ago
30 Aug 2023, 17:21
1.3
2 km West of Zagarise
24 km East · 8 km
3 years ago
1 Sept 2023, 19:47
2.2
12 km South-West of Gizzeria
25 km South-West · 9 km
3 years ago
22 Aug 2023, 11:53
1.6
4 km South-West of Bianchi
10 km North-East · 10 km
3 years ago
8 Sept 2023, 00:35
0.8
1 km North-East of Aprigliano
29 km North · 10 km
3 years ago
8 Sept 2023, 22:13
2.5
2 km North of Aprigliano
30 km North · 16 km
3 years ago
8 Sept 2023, 23:49
1.0
2 km North-East of Aprigliano
30 km North · 14 km
3 years ago
8 Sept 2023, 23:54
2.4
2 km North of Aprigliano
30 km North · 15 km
3 years ago
9 Sept 2023, 12:30

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).