All earthquakes
3.0
weak
EARTHQUAKE DETAILS

4 km North-West of Cervia

124 months ago · 4 Apr, 22:46

A weak earthquake, felt by some of the population. Being deep, it is felt less at the surface.

Stronger than 98% of Italian events in the past year

Where

4 km North-West of CerviaEarthquakes in the province of RavennaEarthquakes 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

3 events
Magnitude:lightweakmoderatestrong

The energy released

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

477kgof TNT equivalent
2.0 lightning bolts
M3
About the same energy as a magnitude 3 earthquake
M2this quakeM4

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 ≈ 14 s

Animation sped up ~3× compared to reality.

  • Ravenna
    16 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Forlì
    18 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Cesena
    20 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Faenza
    30 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 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

38 km
deep
4.3 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~19 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 one aftershock within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
1
last 24 hours
2
last 7 days
7
last 30 days
1 before1 after
this quake
Strongest of the sequence2.1

How often does it happen here?

about every ~3 months

Within 50 km of this epicentre, a magnitude ≥ 3 earthquake has occurred on average this often: 40 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 · 37 km from here
IX-XCompletely destructive: most buildings are destroyed.
16616.0
Appennino forlivese earthquake
22 March 1661 · 40 km from here
XCompletely destructive: most buildings are destroyed.
17686.0
Appennino forlivese earthquake
19 October 1768 · 47 km from here
IXDestructive: many buildings partly or fully collapse.
19186.0
Appennino forlivese earthquake
10 November 1918 · 48 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

Ascensione-Armaia

The epicentre lies about 3 km from Ascensione-Armaia, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.0between 2 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

1.9
19 km East of Ravenna
22 km North-East · 20 km
124 months ago
30 Mar, 03:52
2.1
6 km North-East of Cervia
9 km East · 19 km
123 months ago
4 May, 15:45

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