All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 4 km South-East of Pacentro (AQ)

7 years ago · 18 Dec 2018, 14:43

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

Stronger than 63% of Italian events in the past year

Where

4 km South-East of PacentroEarthquakes 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

14 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 ≈ 18 s

Animation sped up ~3× compared to reality.

  • Chieti
    37 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Pescara
    51 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Montesilvano
    52 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • L'Aquila
    61 km from the epicentre
    first tremor in ~11 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?

Foreshock

In hindsight it was a foreshock: 7 years ago the same area had a stronger quake (M2.2). This can only be said after the fact — it was not predictable beforehand.

2.2
The mainshock
1 km East of Ateleta
7 years ago · 10 Jan 2019, 06:26
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
8
last 30 days
3 before10 after
this quake
Strongest of the sequence2.2

How often does it happen here?

about every ~12 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 346 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 · 43 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17066.8
Maiella earthquake
3 November 1706 · 6 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19335.9
Maiella earthquake
26 September 1933 · 7 km from here
IXDestructive: many buildings partly or fully collapse.
19845.9
Monti della Meta earthquake
7 May 1984 · 40 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

Deep Abruzzo Citeriore Basal Thrust

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

estimated maximum magnitude 7.5between 8 and 18 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

1.7
3 km West of San Pietro Avellana
25 km South-East · 18 km
7 years ago
12 Dec 2018, 17:11
1.0
3 km East of Barrea
29 km South · 16 km
7 years ago
11 Dec 2018, 23:00
1.6
4 km North of Scontrone
27 km South · 9 km
7 years ago
25 Dec 2018, 20:59
0.5
2 km South-West of Pietranico
30 km North-West · 18 km
7 years ago
29 Dec 2018, 22:56
1.8
1 km South-West of Campo di Giove
5 km South-East · 9 km
7 years ago
4 Jan 2019, 08:24
2.1
2 km East of Cansano
4 km South · 9 km
7 years ago
5 Jan 2019, 12:24
2.1
2 km West of Campo di Giove
4 km South · 9 km
7 years ago
5 Jan 2019, 22:10
1.2
7 years ago
6 Jan 2019, 00:59
1.4
7 years ago
29 Nov 2018, 09:09
2.2
1 km East of Ateleta
21 km South-East · 19 km
7 years ago
10 Jan 2019, 06:26

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).