All earthquakes
1.2
very light
EARTHQUAKE DETAILS

M1.2 earthquake · 4 km West of Raveo (UD)

7 years ago · 23 Oct 2018, 19:19

A very light earthquake, probably not felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 48% of Italian events in the past year

Where

4 km West of RaveoEarthquakes 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

20 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.0kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×501 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 ≈ 32 s

Animation sped up ~6× compared to reality.

  • Udine
    55 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Pordenone
    57 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Treviso
    97 km from the epicentre
    first tremor in ~16 s
    main shaking in ~28 s
  • Bolzano
    110 km from the epicentre
    first tremor in ~18 s
    main shaking in ~32 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

11 km
medium depth
1.3 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

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: 7 years ago the same area had a stronger quake (M3.1). This can only be said after the fact — it was not predictable beforehand.

3.1
The mainshock
4 km South-East of Danta di Cadore
7 years ago · 17 Nov 2018, 11:50
Activity in the area right now (30 km radius)
3
last 24 hours
7
last 7 days
22
last 30 days
10 before9 after
this quake
Strongest of the sequence3.1

How often does it happen here?

about every ~18 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 233 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.

19766.5
Friuli earthquake
6 May 1976 · 33 km from here
IX-XCompletely destructive: most buildings are destroyed.
15116.3
Friuli-Slovenia earthquake
26 March 1511 · 41 km from here
IXDestructive: many buildings partly or fully collapse.
18736.3
Alpago Cansiglio earthquake
29 June 1873 · 45 km from here
IX-XCompletely destructive: most buildings are destroyed.
19286.0
Carnia earthquake
27 March 1928 · 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

Tramonti-Montemaggiore

The epicentre lies about 14 km from Tramonti-Montemaggiore, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.2between 1 and 6 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

1.3
3 km South-West of Trasaghis
24 km South-East · 10 km
7 years ago
21 Oct 2018, 00:39
1.1
7 km East of Claut
21 km South-West · 9 km
7 years ago
26 Oct 2018, 15:57
1.1
1 km West of Venzone
29 km East · 9 km
7 years ago
27 Oct 2018, 17:23
0.5
1 km South-West of Trasaghis
24 km South-East · 10 km
7 years ago
18 Oct 2018, 21:59
1.2
4 km South-West of Tolmezzo
18 km East · 8 km
7 years ago
6 Nov 2018, 20:57
1.0
3 km East of Claut
26 km South-West · 9 km
8 years ago
7 Oct 2018, 20:44
1.0
4 km South-East of Claut
27 km South-West · 10 km
8 years ago
7 Oct 2018, 12:31
1.2
2 km South-East of Bordano
28 km South-East · 8 km
7 years ago
10 Nov 2018, 20:18
0.8
3 km South-East of Cavazzo Carnico
23 km South-East · 14 km
8 years ago
5 Oct 2018, 14:26
1.6
4 km South-East of Preone
15 km South-East · 10 km
7 years ago
15 Nov 2018, 19:59

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).