All earthquakes
1.2
very light
EARTHQUAKE DETAILS

8 km North-West of Forlì

136 months ago · 24 Apr, 20:16

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

Stronger than 47% of Italian events in the past year

Where

8 km North-West of ForlìEarthquakes in the province of Forlì-CesenaEarthquakes in Emilia-Romagna

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

61 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.0kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×501 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 ≈ 9 s

Animation sped up ~2× compared to reality.

  • Faenza
    7 km from the epicentre
    first tremor in ~3 s
    main shaking in ~6 s
  • Forlì
    8 km from the epicentre
    first tremor in ~3 s
    main shaking in ~6 s
  • Ravenna
    22 km from the epicentre
    first tremor in ~5 s
    main shaking in ~8 s
  • Imola
    25 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 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

18 km
medium depth
2 times the height of Mount Everest

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

in line with the area average (~13 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 (M4.0, 136 months ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

4.0
The mainshock
5 km South of Faenza
136 months ago · 24 Apr, 17:02
Activity in the area right now (30 km radius)
0
last 24 hours
4
last 7 days
10
last 30 days
37 before86 after
this quake
Strongest of the sequence4.0

How often does it happen here?

about every ~7 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 633 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.

17816.1
Faentino earthquake
4 April 1781 · 14 km from here
IX-XCompletely destructive: most buildings are destroyed.
16616.0
Appennino forlivese earthquake
22 March 1661 · 27 km from here
XCompletely destructive: most buildings are destroyed.
17686.0
Appennino forlivese earthquake
19 October 1768 · 36 km from here
IXDestructive: many buildings partly or fully collapse.
15846.0
Appennino forlivese earthquake
10 September 1584 · 44 km from here
IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Castel San Pietro Terme-Meldola

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

estimated maximum magnitude 6.5between 2 and 8 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

1.6
1 km South-East of Faenza
6 km West · 29 km
136 months ago
24 Apr, 20:25
1.5
4 km West of Faenza
10 km West · 28 km
136 months ago
24 Apr, 20:33
2.2
7 km South-East of Faenza
4 km South-West · 21 km
136 months ago
24 Apr, 19:56
2.0
5 km East of Faenza
3 km North-West · 27 km
136 months ago
24 Apr, 20:37
1.4
8 km North-West of Forlì
1 km South-East · 21 km
136 months ago
24 Apr, 19:47
1.9
7 km South-East of Faenza
4 km West · 22 km
136 months ago
24 Apr, 19:46
1.4
4 km South of Faenza
7 km West · 26 km
136 months ago
24 Apr, 19:44
1.8
7 km South of Faenza
7 km West · 20 km
136 months ago
24 Apr, 19:43
1.0
5 km South-West of Faenza
9 km West · 23 km
136 months ago
24 Apr, 20:53
2.2
6 km South-East of Faenza
5 km West · 22 km
136 months ago
24 Apr, 20:59

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