All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 4 km South-West of Pescasseroli (AQ)

8 years ago · 26 Dec 2017, 21:41

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 63% of Italian events in the past year

Where

4 km South-West of PescasseroliEarthquakes 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

24 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.9kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×251 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 ≈ 24 s

Animation sped up ~5× compared to reality.

  • L'Aquila
    66 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Chieti
    71 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Latina
    84 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 s
  • Velletri
    85 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 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 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 (~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 (M2.2, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.2
The mainshock
3 km South of Villalago
8 years ago · 17 Dec 2017, 11:20
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
7
last 30 days
8 before15 after
this quake
Strongest of the sequence2.2

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: 397 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 · 34 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17066.8
Maiella earthquake
3 November 1706 · 42 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.8
Lazio-Molise earthquake
9 September 1349 · 28 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16546.3
Sorano earthquake
24 July 1654 · 17 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

Salto Lake-Ovindoli-Barrea

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

estimated maximum magnitude 7.1between 1 and 15 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
8 years ago
22 Dec 2017, 02:51
1.2
2 km South of Trasacco
26 km North-West · 15 km
8 years ago
21 Dec 2017, 06:19
2.2
3 km South of Villalago
16 km North · 11 km
8 years ago
17 Dec 2017, 11:20
0.6
1 km East of Balsorano
15 km West · 9 km
8 years ago
8 Jan 2018, 03:12
1.1
3 km South of Lecce nei Marsi
14 km North-West · 11 km
8 years ago
9 Jan 2018, 13:36
0.8
8 years ago
11 Dec 2017, 15:53
0.8
5 km North of Opi
9 km North-East · 11 km
8 years ago
11 Dec 2017, 10:22
1.2
2 km South-West of Pizzone
21 km South-East · 16 km
8 years ago
12 Jan 2018, 19:44
1.9
2 km South of Lecce nei Marsi
16 km North-West · 15 km
8 years ago
14 Jan 2018, 01:36
1.1
4 km North of Ortucchio
26 km North-West · 10 km
8 years ago
14 Jan 2018, 20:17

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).