All earthquakes
0.6
very light
EARTHQUAKE DETAILS

M0.6 earthquake · 2 km North of Tolmezzo (UD)

6 years ago · 20 Dec 2019, 15:40

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 7% of Italian events in the past year

Where

2 km North of TolmezzoEarthquakes in the province of UdineEarthquakes in Friuli-Venezia Giulia

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

16 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.1kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×3,981 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 ≈ 31 s

Animation sped up ~6× compared to reality.

  • Udine
    46 km from the epicentre
    first tremor in ~8 s
    main shaking in ~13 s
  • Pordenone
    65 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Trieste
    106 km from the epicentre
    first tremor in ~18 s
    main shaking in ~30 s
  • Treviso
    108 km from the epicentre
    first tremor in ~18 s
    main shaking in ~31 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 (~9 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: 6 years ago the same area had a stronger quake (M2.0). This can only be said after the fact — it was not predictable beforehand.

2.0
The mainshock
2 km West of Enemonzo
6 years ago · 8 Jan 2020, 14:35
Activity in the area right now (30 km radius)
2
last 24 hours
7
last 7 days
20
last 30 days
9 before6 after
this quake
Strongest of the sequence2.0

How often does it happen here?

about every ~17 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 247 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.

13486.6
Alpi Giulie earthquake
25 January 1348 · 41 km from here
IX-XCompletely destructive: most buildings are destroyed.
19766.5
Friuli earthquake
6 May 1976 · 24 km from here
IX-XCompletely destructive: most buildings are destroyed.
15116.3
Friuli-Slovenia earthquake
26 March 1511 · 30 km from here
IXDestructive: many buildings partly or fully collapse.
19286.0
Carnia earthquake
27 March 1928 · 11 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

But-Chiarso

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

estimated maximum magnitude 6.3between 1 and 9 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

1.0
1 km North of Tolmezzo
1 km South-West · 14 km
6 years ago
20 Dec 2019, 08:13
0.7
0 km North of Amaro
8 km South-East · 12 km
6 years ago
18 Dec 2019, 07:37
0.5
2 km East of Preone
15 km South-West · 8 km
6 years ago
24 Dec 2019, 19:48
0.8
3 km North-West of Osoppo
21 km South · 10 km
6 years ago
13 Dec 2019, 02:32
0.9
2 km East of Trasaghis
18 km South · 10 km
6 years ago
6 Dec 2019, 08:00
2.0
2 km West of Enemonzo
17 km West · 9 km
6 years ago
8 Jan 2020, 14:35
1.0
2 km South-East of Bordano
16 km South-East · 10 km
6 years ago
1 Dec 2019, 15:53
1.7
7 km West of Pontebba
16 km North-East · 9 km
6 years ago
1 Dec 2019, 12:16
1.0
3 km North of Vito d'Asio
18 km South-West · 8 km
6 years ago
1 Dec 2019, 00:47
1.0
4 km East of Lusevera
27 km South-East · 12 km
6 years ago
30 Nov 2019, 12:30

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).