All earthquakes
0.8
very light
EARTHQUAKE DETAILS

M0.8 earthquake · 3 km North-West of Pettorano sul Gizio (AQ)

8 years ago · 17 Oct 2017, 18:30

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

Stronger than 17% of Italian events in the past year

Where

3 km North-West of Pettorano sul GizioEarthquakes in the province of L'AquilaEarthquakes in Abruzzo

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

37 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.2kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,995 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 ≈ 18 s

Animation sped up ~3× compared to reality.

  • Chieti
    46 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • L'Aquila
    56 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Montesilvano
    60 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • Pescara
    60 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 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

18 km
medium depth
2 times the height of Mount Everest

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

deeper than the area average (~12 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 (M2.7, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.7
The mainshock
1 km South-West of Ateleta
8 years ago · 16 Oct 2017, 05:45
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
8
last 30 days
28 before8 after
this quake
Strongest of the sequence2.7

How often does it happen here?

about every ~11 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 378 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.

19157.1
Marsica earthquake
13 January 1915 · 33 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17066.8
Maiella earthquake
3 November 1706 · 18 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.8
Lazio-Molise earthquake
9 September 1349 · 47 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
14616.5
Aquilano earthquake
27 November 1461 · 49 km from here
XCompletely destructive: most buildings are destroyed.

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

The closest seismic structure

Borbona-L'Aquila-Aremogna

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

estimated maximum magnitude 7.0between 2 and 14 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
4 km North-West of Pescasseroli
21 km South-West · 11 km
8 years ago
16 Oct 2017, 13:26
1.2
3 km East of Bisegna
11 km South-West · 11 km
8 years ago
16 Oct 2017, 06:56
2.7
1 km South-West of Ateleta
23 km South-East · 10 km
8 years ago
16 Oct 2017, 05:45
0.5
2 km North-East of Campoli Appennino
28 km South-West · 29 km
9 years ago
10 Oct 2017, 07:21
0.7
6 km West of Scanno
13 km South-West · 13 km
9 years ago
7 Oct 2017, 07:14
1.5
6 km South-East of Bisegna
13 km South-West · 18 km
9 years ago
7 Oct 2017, 06:15
0.9
6 km West of Scanno
13 km South-West · 15 km
9 years ago
7 Oct 2017, 05:40
1.8
6 km South-East of Bisegna
13 km South-West · 18 km
9 years ago
7 Oct 2017, 05:27
2.6
6 km South-East of Bisegna
14 km South-West · 19 km
9 years ago
7 Oct 2017, 05:22
0.9
6 km West of Scanno
13 km South-West · 15 km
9 years ago
7 Oct 2017, 05:14

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).