All earthquakes
1.8
very light
EARTHQUAKE DETAILS

M1.8 earthquake · 4 km East of Isola di Capo Rizzuto (KR)

2 years ago · 7 Nov 2023, 09:12

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

Stronger than 82% of Italian events in the past year

Where

4 km East of Isola di Capo RizzutoEarthquakes in the province of CrotoneEarthquakes 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

15 events
Magnitude:lightweakmoderatestrong

The energy released

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

7.6kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×63 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 ~5× compared to reality.

  • Crotone
    16 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Catanzaro
    45 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Lamezia Terme
    72 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 s
  • Cosenza
    81 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

26 km
medium depth
3 times the height of Mount Everest

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

deeper than the area average (~20 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 (M3.0, 2 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.0
The mainshock
10 km East of Isola di Capo Rizzuto
2 years ago · 6 Nov 2023, 21:02
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
1
last 30 days
8 before6 after
this quake
Strongest of the sequence3.0

How often does it happen here?

about every ~10 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 422 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.

16386.8
Crotonese earthquake
8 June 1638 · 44 km from here
XCompletely destructive: most buildings are destroyed.
18326.7
Crotonese earthquake
8 March 1832 · 22 km from here
XCompletely destructive: most buildings are destroyed.
17445.7
Sila Piccola earthquake
21 March 1744 · 30 km from here
IXDestructive: many buildings partly or fully collapse.
19325.5
Ionio settentrionale earthquake
2 January 1932 · 40 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.

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

The closest seismic structure

Crotone-Rossano

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

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

2.9
2 years ago
7 Nov 2023, 08:58
1.2
4 km South of Isola di Capo Rizzuto
6 km South-West · 21 km
2 years ago
7 Nov 2023, 03:37
1.4
2 years ago
6 Nov 2023, 21:19
1.3
2 years ago
6 Nov 2023, 21:05
3.0
10 km East of Isola di Capo Rizzuto
7 km South-East · 24 km
2 years ago
6 Nov 2023, 21:02
2.5
2 years ago
6 Nov 2023, 20:11
1.9
2 years ago
6 Nov 2023, 20:09
2.1
2 years ago
6 Nov 2023, 19:36
1.8
2 years ago
17 Nov 2023, 12:27
2.4
2 years ago
28 Nov 2023, 21:17

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).