All earthquakes
1.2
very light
EARTHQUAKE DETAILS

M1.2 earthquake · 4 km West of Tenno (TN)

11 years ago · 2 Aug 2015, 15:10

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 48% of Italian events in the past year

Where

4 km West of TennoEarthquakes in the province of TrentoEarthquakes 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

31 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • Trento
    29 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Verona
    56 km from the epicentre
    first tremor in ~10 s
    main shaking in ~16 s
  • Brescia
    61 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • Vicenza
    73 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

10 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 (~7 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 (M3.7, 11 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.7
The mainshock
5 km North-West of Riva del Garda
11 years ago · 1 Aug 2015, 22:47
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
4
last 30 days
9 before21 after
this quake
Strongest of the sequence3.7

How often does it happen here?

about every ~32 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 135 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.

18915.9
Valle d'Illasi earthquake
7 June 1891 · 50 km from here
IXDestructive: many buildings partly or fully collapse.
12225.7
Bresciano-Veronese earthquake
25 December 1222 · 45 km from here
19015.4
Garda occidentale earthquake
30 October 1901 · 44 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19325.2
Garda orientale earthquake
19 February 1932 · 32 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Giudicarie

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

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

2.2
11 years ago
2 Aug 2015, 15:47
1.1
5 km West of Tenno
1 km South-West · 5 km
11 years ago
2 Aug 2015, 16:07
1.4
4 km South-West of Tenno
1 km South-East · 11 km
11 years ago
2 Aug 2015, 16:12
1.8
11 years ago
2 Aug 2015, 17:16
1.8
4 km North-West of Riva del Garda
3 km South-East · 10 km
11 years ago
2 Aug 2015, 11:55
1.4
4 km South-West of Tenno
1 km South-West · 9 km
11 years ago
2 Aug 2015, 18:42
1.3
3 km West of Tenno
1 km East · 11 km
11 years ago
2 Aug 2015, 10:41
1.4
4 km West of Tenno
1 km North · 10 km
11 years ago
2 Aug 2015, 08:55
1.3
4 km South-West of Dro
11 km East · 12 km
11 years ago
2 Aug 2015, 21:38
1.5
4 km South-West of Tenno
1 km South-East · 10 km
11 years ago
2 Aug 2015, 23:06

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).