All earthquakes
1.8
very light
EARTHQUAKE DETAILS

M1.8 earthquake · 11 km South-West of Diamante (CS)

2 years ago · 26 Dec 2023, 00:46

A very light earthquake, probably not felt by people. Being deep, it is felt less at the surface.

Stronger than 82% of Italian events in the past year

Where

11 km South-West of DiamanteEarthquakes in the province of CosenzaEarthquakes 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

5 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 ≈ 40 s

Animation sped up ~8× compared to reality.

  • Cosenza
    61 km from the epicentre
    first tremor in ~18 s
    main shaking in ~30 s
  • Corigliano-Rossano
    61 km from the epicentre
    first tremor in ~18 s
    main shaking in ~30 s
  • Lamezia Terme
    89 km from the epicentre
    first tremor in ~21 s
    main shaking in ~35 s
  • Catanzaro
    111 km from the epicentre
    first tremor in ~23 s
    main shaking in ~40 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

86 km
deep
9.7 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~43 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 2 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
4
last 30 days
2 before2 after
this quake
Strongest of the sequence1.4

How often does it happen here?

about every ~9 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 477 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.

11846.8
Valle del Crati earthquake
24 May 1184 · 48 km from here
IXDestructive: many buildings partly or fully collapse.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 46 km from here
19135.6
Calabria settentrionale earthquake
28 June 1913 · 46 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
17085.6
Pollino earthquake
26 January 1708 · 47 km from here
VIII-IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Rimendiello-Mormanno

The epicentre lies about 35 km from Rimendiello-Mormanno, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.6between 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

1.3
3 km East of Grisolia
21 km North-East · 25 km
2 years ago
28 Dec 2023, 16:05
0.7
4 km East of Buonvicino
19 km East · 22 km
2 years ago
28 Dec 2023, 17:32
1.1
0 km South of San Sosti
28 km East · 35 km
2 years ago
19 Dec 2023, 11:23
1.4
2 years ago
15 Dec 2023, 17:04

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).