All earthquakes
1.0
very light
EARTHQUAKE DETAILS

16 km South of Bordighera

100 months ago · 3 Jun, 16:14

A very light earthquake, probably not felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 30% of Italian events in the past year

Where

16 km South of BordigheraEarthquakes 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

4 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 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 ≈ 35 s

Animation sped up ~7× compared to reality.

  • Sanremo
    20 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • Cuneo
    85 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 s
  • Savona
    93 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Genova
    122 km from the epicentre
    first tremor in ~20 s
    main shaking in ~35 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

8 km
shallow

At only a few km deep the shaking is felt more sharply at the surface.

in line with the area average (~10 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 (M2.8, 100 months ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.8
The mainshock
Costa Ligure Occidentale (Imperia)
100 months ago · 3 Jun, 03:47
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
2
last 30 days
3 before0 after
this quake
Strongest of the sequence2.8

How often does it happen here?

about every ~4 months

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 39 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 · 33 km from here
XCompletely destructive: most buildings are destroyed.
19636.0
Mar Ligure earthquake
19 July 1963 · 48 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
18545.7
Liguria occidentale earthquake
29 December 1854 · 28 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
16185.6
Alpes Niçoises earthquake
18 January 1618 · 48 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

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

2.8
100 months ago
3 Jun, 03:47
1.0
7 km South of Riva Ligure
17 km North-East · 11 km
101 months ago
20 May, 09:34
0.5
3 km South-East of Pigna
28 km North · 10 km
101 months ago
17 May, 16:31

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