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2.2
light
EARTHQUAKE DETAILS

M2.2 earthquake · 4 km South-West of Poggio Rusco (MN)

4 years ago · 17 Oct 2021, 07:56

A light earthquake, rarely felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 92% of Italian events in the past year

Where

4 km South-West of Poggio RuscoEarthquakes in the province of MantovaEarthquakes in Lombardia

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

8 events
Magnitude:lightweakmoderatestrong

The energy released

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

30kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×16 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 ≈ 14 s

Animation sped up ~3× compared to reality.

  • Carpi
    24 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 s
  • Modena
    32 km from the epicentre
    first tremor in ~6 s
    main shaking in ~9 s
  • Ferrara
    45 km from the epicentre
    first tremor in ~8 s
    main shaking in ~13 s
  • Reggio nell'Emilia
    49 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

9 km
shallow

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

in line with the area average (~12 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 (M2.3, 5 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.3
The mainshock
4 km North-East of San Felice sul Panaro
5 years ago · 22 Sept 2021, 07:32
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
2
last 30 days
5 before2 after
this quake
Strongest of the sequence2.3

How often does it happen here?

about every ~15 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 284 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.

11176.5
Veronese earthquake
3 January 1117 · 38 km from here
IXDestructive: many buildings partly or fully collapse.
20126.1
Pianura emiliana earthquake
20 May 2012 · 11 km from here
VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
20125.9
Pianura emiliana earthquake
29 May 2012 · 12 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
15055.6
Bolognese earthquake
3 January 1505 · 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

Poggio Rusco-Migliarino

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

estimated maximum magnitude 6.8between 1 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

2.2
6 km South-East of Finale Emilia
20 km South-East · 10 km
4 years ago
26 Oct 2021, 06:42
1.9
4 km East of San Felice sul Panaro
11 km South-East · 9 km
5 years ago
3 Oct 2021, 01:44
1.8
5 years ago
3 Oct 2021, 01:32
2.1
4 km East of San Felice sul Panaro
9 km South-East · 6 km
5 years ago
2 Oct 2021, 04:19
1.9
5 km West of Finale Emilia
11 km South-East · 7 km
5 years ago
26 Sept 2021, 07:58
2.3
5 years ago
22 Sept 2021, 07:32
1.7
7 km East of Finale Emilia
20 km East · 25 km
4 years ago
12 Nov 2021, 01:31

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).