All earthquakes
1.3
very light
EARTHQUAKE DETAILS

M1.3 earthquake · 3 km South of Vastogirardi (IS)

8 years ago · 12 Jan 2018, 12:42

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

Stronger than 55% of Italian events in the past year

Where

3 km South of VastogirardiEarthquakes in the province of IserniaEarthquakes in Molise

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

61 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×355 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 ~4× compared to reality.

  • Caserta
    69 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Chieti
    69 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Benevento
    78 km from the epicentre
    first tremor in ~13 s
    main shaking in ~23 s
  • Pescara
    81 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

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 (~13 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 (M2.6, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.6
The mainshock
2 km West of Vastogirardi
8 years ago · 26 Dec 2017, 06:33
Activity in the area right now (30 km radius)
1
last 24 hours
12
last 7 days
20
last 30 days
107 before66 after
this quake
Strongest of the sequence2.6

How often does it happen here?

about every ~9 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 506 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.

17066.8
Maiella earthquake
3 November 1706 · 41 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.8
Lazio-Molise earthquake
9 September 1349 · 34 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18056.7
Molise earthquake
26 July 1805 · 31 km from here
XCompletely destructive: most buildings are destroyed.
16546.3
Sorano earthquake
24 July 1654 · 50 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

Deep Abruzzo Citeriore Basal Thrust

The epicentre lies about 6 km from Deep Abruzzo Citeriore Basal Thrust, one of the seismic structures mapped by INGV geologists.

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

1.3
1 km South-West of Vastogirardi
2 km North-West · 16 km
8 years ago
12 Jan 2018, 13:01
1.4
4 km South-East of Ateleta
14 km North-West · 19 km
8 years ago
12 Jan 2018, 05:54
1.2
2 km South-West of Pizzone
25 km West · 16 km
8 years ago
12 Jan 2018, 19:44
1.9
3 km South of Vastogirardi
1 km West · 17 km
8 years ago
12 Jan 2018, 21:19
1.6
4 km South-East of Ateleta
13 km North-West · 19 km
8 years ago
11 Jan 2018, 22:35
1.4
8 years ago
13 Jan 2018, 10:28
1.5
2 km South-West of Vastogirardi
2 km North-West · 18 km
8 years ago
13 Jan 2018, 20:25
1.0
8 years ago
13 Jan 2018, 20:57
0.9
8 years ago
14 Jan 2018, 01:40
1.4
4 km South-East of Ateleta
13 km North-West · 20 km
8 years ago
14 Jan 2018, 01:54

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).