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2.0
light
EARTHQUAKE DETAILS

M2.0 earthquake · 1 km North-East of Bedonia (PR)

8 years ago · 21 Oct 2017, 20:36

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

Stronger than 88% of Italian events in the past year

Where

1 km North-East of BedoniaEarthquakes in the province of ParmaEarthquakes 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

7 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 ≈ 19 s

Animation sped up ~3× compared to reality.

  • La Spezia
    52 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Piacenza
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Genova
    61 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • Carrara
    64 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 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.

shallower than the area average (~16 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 (M2.4, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.4
The mainshock
4 km North-East of Sesta Godano
8 years ago · 13 Oct 2017, 06:36
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
4
last 30 days
3 before3 after
this quake
Strongest of the sequence2.4

How often does it happen here?

about every ~5 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 787 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.

18346.0
Val di Taro-Lunigiana earthquake
14 February 1834 · 24 km from here
IXDestructive: many buildings partly or fully collapse.
15455.4
Val di Taro earthquake
9 June 1545 · 20 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18735.3
Appennino tosco-ligure earthquake
17 September 1873 · 40 km from here
VI-VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
19035.2
Lunigiana earthquake
27 July 1903 · 37 km from here
VII-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

Lunigiana

The epicentre lies about 2 km from Lunigiana, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.0between 1 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

2.4
4 km North-East of Sesta Godano
27 km South-East · 63 km
8 years ago
13 Oct 2017, 06:36
1.2
3 km West of Pontremoli
24 km South-East · 9 km
9 years ago
8 Oct 2017, 22:29
1.3
2 km South-West of Varsi
22 km East · 28 km
8 years ago
4 Nov 2017, 02:49
1.1
9 years ago
6 Oct 2017, 00:30
1.7
3 km South of Valmozzola
22 km East · 8 km
8 years ago
19 Nov 2017, 16:14
2.0
3 km South of Valmozzola
22 km East · 9 km
8 years ago
19 Nov 2017, 21:59

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).