All earthquakes
0.9
very light
EARTHQUAKE DETAILS

2 km West of Borgo Pace

21 months ago · 3 Dec, 14:14

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 23% of Italian events in the past year

Where

2 km West of Borgo PaceEarthquakes in the province of Pesaro e UrbinoEarthquakes in Marche

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.

0.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,413 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 ≈ 15 s

Animation sped up ~3× compared to reality.

  • Arezzo
    34 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Rimini
    48 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Cesena
    49 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Pesaro
    54 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 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

7 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?

Foreshock

In hindsight it was a foreshock: 21 months ago the same area had a stronger quake (M2.5). This can only be said after the fact — it was not predictable beforehand.

2.5
The mainshock
7 km East of Pietralunga
21 months ago · 19 Dec, 10:59
Activity in the area right now (30 km radius)
4
last 24 hours
17
last 7 days
56
last 30 days
39 before21 after
this quake
Strongest of the sequence2.5

How often does it happen here?

about every ~8 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 545 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.

17816.5
Cagliese earthquake
3 June 1781 · 24 km from here
XCompletely destructive: most buildings are destroyed.
13526.3
Alta Valtiberina earthquake
25 December 1352 · 22 km from here
IXDestructive: many buildings partly or fully collapse.
16616.0
Appennino forlivese earthquake
22 March 1661 · 49 km from here
XCompletely destructive: most buildings are destroyed.
13896.0
Alta Valtiberina earthquake
18 October 1389 · 15 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

Piandimeleto-Bavareto

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

estimated maximum magnitude 7.1between 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

1.4
21 months ago
3 Dec, 05:26
0.9
21 months ago
4 Dec, 09:30
0.7
6 km North-East of Piobbico
29 km East · 6 km
21 months ago
2 Dec, 08:10
0.8
2 km East of San Giustino
11 km South · 8 km
21 months ago
7 Dec, 22:53
0.5
3 km East of Piobbico
27 km East · 5 km
21 months ago
11 Dec, 08:11
0.8
21 months ago
11 Dec, 18:15
0.5
4 km West of Pietralunga
24 km South-East · 8 km
21 months ago
24 Nov, 10:38
0.7
5 km North of Verghereto
26 km North-West · 9 km
21 months ago
24 Nov, 05:59
1.9
3 km South-East of Pietralunga
30 km South-East · 8 km
21 months ago
13 Dec, 01:21
1.8
3 km West of Maiolo
25 km North · 36 km
21 months ago
23 Nov, 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).

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