All earthquakes
0.9
very light
EARTHQUAKE DETAILS

M0.9 earthquake · 6 km South-West of Martello (BZ)

10 years ago · 29 Oct 2015, 16:21

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

Stronger than 23% of Italian events in the past year

Where

6 km South-West of MartelloEarthquakes in the province of BolzanoEarthquakes in Trentino-Alto Adige

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

7 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 ≈ 34 s

Animation sped up ~6× compared to reality.

  • Bolzano
    53 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Trento
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Brescia
    111 km from the epicentre
    first tremor in ~19 s
    main shaking in ~32 s
  • Bergamo
    117 km from the epicentre
    first tremor in ~20 s
    main shaking in ~34 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 (~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?

Aftershock

It is an aftershock: it follows a stronger quake (M1.5, 10 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.5
The mainshock
11 km North-West of Peio
10 years ago · 15 Oct 2015, 02:32
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
12
last 30 days
2 before4 after
this quake
Strongest of the sequence1.5

How often does it happen here?

about every ~3 months

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 46 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.

18275.0
Bassa Engadina, Ardez earthquake
2 April 1827 · 50 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
19614.9
Val Monastero earthquake
9 August 1961 · 44 km from here
V-VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
20014.8
Val Venosta earthquake
17 July 2001 · 39 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.
19994.8
Alpi Retiche earthquake
29 December 1999 · 29 km from here
V-VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.

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

The closest seismic structure

Giudicarie

The epicentre lies about 43 km from Giudicarie, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.8between 5 and 12 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 North of Bormio
20 km West · 11 km
10 years ago
2 Nov 2015, 21:55
1.0
8 km North-East of Peio
5 km South · 10 km
10 years ago
10 Nov 2015, 01:08
1.5
11 km North-West of Peio
6 km West · 10 km
10 years ago
15 Oct 2015, 02:32
1.1
8 km North-East of Peio
5 km South-East · 9 km
10 years ago
13 Nov 2015, 08:50
0.8
5 km North of Martello
10 km North-East · 12 km
10 years ago
22 Nov 2015, 23:39
0.7
3 km East of Valdisotto
23 km West · 8 km
11 years ago
4 Oct 2015, 05:01

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).