All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 3 km East of Cerami (EN)

3 years ago · 21 Jun 2023, 02:35

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

Stronger than 69% of Italian events in the past year

Where

3 km East of CeramiEarthquakes in the province of EnnaEarthquakes in Sicilia

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

42 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 ≈ 25 s

Animation sped up ~5× compared to reality.

  • Catania
    58 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Acireale
    59 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Caltanissetta
    60 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Gela
    81 km from the epicentre
    first tremor in ~15 s
    main shaking in ~25 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

36 km
deep
4 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~14 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 (M4.0). This can only be said after the fact — it was not predictable beforehand.

4.0
The mainshock
6 km South-East of San Teodoro
3 years ago · 5 Jul 2023, 06:07
Activity in the area right now (30 km radius)
0
last 24 hours
5
last 7 days
20
last 30 days
2 before39 after
this quake
Strongest of the sequence4.0

How often does it happen here?

about every ~2 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 2040 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.

18235.8
Sicilia settentrionale earthquake
5 March 1823 · 45 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
16135.6
Monti Nebrodi earthquake
25 August 1613 · 41 km from here
IXDestructive: many buildings partly or fully collapse.
17395.4
Monti Nebrodi earthquake
10 May 1739 · 37 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
18195.4
Monti Madonie earthquake
24 February 1819 · 45 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Gela-Catania

The epicentre lies about 40 km from Gela-Catania, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 3 and 10 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

2.2
4 km East of Caronia
18 km North · 4 km
3 years ago
30 Jun 2023, 00:20
4.0
3 years ago
5 Jul 2023, 06:07
3.5
7 km South of San Teodoro
15 km East · 27 km
3 years ago
5 Jul 2023, 06:08
2.5
6 km South of San Teodoro
16 km East · 29 km
3 years ago
5 Jul 2023, 06:10
2.4
3 years ago
5 Jul 2023, 06:11
2.2
5 km South of San Teodoro
15 km East · 29 km
3 years ago
5 Jul 2023, 06:12
2.2
3 years ago
5 Jul 2023, 06:13
2.2
6 km South of San Teodoro
16 km East · 33 km
3 years ago
5 Jul 2023, 06:15
2.2
3 years ago
5 Jul 2023, 06:23
2.0
3 years ago
5 Jul 2023, 06:28

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).