All earthquakes
2.0
light
EARTHQUAKE DETAILS

24 km South-East of Cervo

120 months ago · 8 Oct, 23:19

A light earthquake, rarely felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 88% of Italian events in the past year

Where

24 km South-East of CervoEarthquakes in the province of ImperiaEarthquakes in Liguria

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.

15kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×32 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 ≈ 27 s

Animation sped up ~5× compared to reality.

  • Sanremo
    46 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Savona
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Genova
    79 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 s
  • Cuneo
    94 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 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

16 km
medium depth
1.8 times the height of Mount Everest

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

deeper than the area average (~8 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: 120 months ago the same area had a stronger quake (M3.1). This can only be said after the fact — it was not predictable beforehand.

3.1
The mainshock
Costa Ligure centro-occidentale (Savona)
120 months ago · 8 Oct, 23:37
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
1
last 30 days
1 before3 after
this quake
Strongest of the sequence3.1

How often does it happen here?

about every ~3 months

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 47 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.

18876.3
Liguria occidentale earthquake
23 February 1887 · 31 km from here
XCompletely destructive: most buildings are destroyed.
18315.6
Liguria occidentale earthquake
26 May 1831 · 41 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
18185.3
Liguria occidentale earthquake
23 February 1818 · 29 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19635.0
Mar Ligure earthquake
27 July 1963 · 32 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

Imperia Promontory

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

estimated maximum magnitude 7.4between 3 and 15 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

3.1
120 months ago
8 Oct, 23:37
1.3
15 km South-East of Laigueglia
10 km North-West · 9 km
120 months ago
8 Oct, 23:47
1.5
120 months ago
9 Oct, 09:46
1.7
14 km East of Albenga
23 km North · 7 km
121 months ago
20 Sept, 07:28

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).

We use cookies to analyse site traffic and improve your experience.

Privacy PolicyCookie Policy