All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 3 km East of Montenars (UD)

7 years ago · 20 Dec 2018, 06:53

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 39% of Italian events in the past year

Where

3 km East of MontenarsEarthquakes 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

17 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×708 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 ≈ 29 s

Animation sped up ~5× compared to reality.

  • Udine
    24 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 s
  • Pordenone
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Trieste
    82 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 s
  • Treviso
    102 km from the epicentre
    first tremor in ~17 s
    main shaking in ~29 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
1.1 times the height of Mount Everest

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: 7 years ago the same area had a stronger quake (M2.4). This can only be said after the fact — it was not predictable beforehand.

2.4
The mainshock
6 km South-West of Moggio Udinese
7 years ago · 15 Jan 2019, 19:31
Activity in the area right now (30 km radius)
0
last 24 hours
5
last 7 days
14
last 30 days
13 before3 after
this quake
Strongest of the sequence2.4

How often does it happen here?

about every ~16 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 262 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 · 37 km from here
IX-XCompletely destructive: most buildings are destroyed.
19766.5
Friuli earthquake
6 May 1976 · 9 km from here
IX-XCompletely destructive: most buildings are destroyed.
15116.3
Friuli-Slovenia earthquake
26 March 1511 · 7 km from here
IXDestructive: many buildings partly or fully collapse.
19286.0
Carnia earthquake
27 March 1928 · 23 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

Trasaghis-Taipana

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

estimated maximum magnitude 6.3between 6 and 11 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
6 km West of Pontebba
28 km North · 11 km
7 years ago
17 Dec 2018, 05:03
1.4
6 km North of Moggio Udinese
28 km North · 8 km
7 years ago
16 Dec 2018, 13:32
0.9
1 km South-East of Tolmezzo
22 km North-West · 9 km
7 years ago
25 Dec 2018, 02:24
1.3
3 km North of Trasaghis
16 km West · 15 km
7 years ago
15 Dec 2018, 01:38
1.1
1 km South of Lusevera
4 km East · 10 km
7 years ago
11 Dec 2018, 17:03
0.6
7 years ago
7 Dec 2018, 13:26
0.9
0 km West of Venzone
10 km North-West · 9 km
7 years ago
4 Dec 2018, 10:52
0.9
4 km North-East of Gemona del Friuli
5 km North-West · 10 km
7 years ago
5 Jan 2019, 04:10
1.6
7 km North of Savogna
26 km East · 10 km
7 years ago
4 Dec 2018, 06:48
0.6
5 km South-East of Resiutta
7 km North · 6 km
7 years ago
3 Dec 2018, 05:11

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).