All earthquakes
1.7
very light
EARTHQUAKE DETAILS

M1.7 earthquake · 3 km West of Belluno (BL)

11 years ago · 26 Jul 2015, 00:02

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 78% of Italian events in the past year

Where

3 km West of BellunoEarthquakes in the province of BellunoEarthquakes in Veneto

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

4 events
Magnitude:lightweakmoderatestrong

The energy released

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

5.4kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×89 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • Pordenone
    43 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Treviso
    51 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Bolzano
    74 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Venezia
    74 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 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

8 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: 11 years ago the same area had a stronger quake (M2.7). This can only be said after the fact — it was not predictable beforehand.

2.7
The mainshock
3 km South of Erto e Casso
11 years ago · 22 Aug 2015, 14:27
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
2
last 30 days
0 before3 after
this quake
Strongest of the sequence2.7

How often does it happen here?

about every ~29 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 146 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.

16956.4
Asolano earthquake
25 February 1695 · 35 km from here
XCompletely destructive: most buildings are destroyed.
18736.3
Alpago Cansiglio earthquake
29 June 1873 · 18 km from here
IX-XCompletely destructive: most buildings are destroyed.
19366.1
Alpago Cansiglio earthquake
18 October 1936 · 17 km from here
IXDestructive: many buildings partly or fully collapse.
17765.8
Prealpi Friulane earthquake
10 July 1776 · 44 km from here
VIII-IXDestructive: many buildings partly or fully collapse.

Source: Parametric Catalogue of Italian Earthquakes CPTI15 (INGV, CC BY 4.0).

The closest seismic structure

Bassano-Vittorio Veneto

The epicentre lies about 4 km from Bassano-Vittorio Veneto, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 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

0.9
2 km South of Quero Vas
29 km South-West · 6 km
11 years ago
22 Aug 2015, 04:54
0.9
3 km South of Quero Vas
29 km South-West · 5 km
11 years ago
22 Aug 2015, 05:09
2.7
3 km South of Erto e Casso
21 km North-East · 4 km
11 years ago
22 Aug 2015, 14:27

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).