All earthquakes
1.3
very light
EARTHQUAKE DETAILS

M1.3 earthquake · 3 km North-West of Pescocostanzo (AQ)

11 years ago · 8 Aug 2015, 11:31

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 55% of Italian events in the past year

Where

3 km North-West of PescocostanzoEarthquakes 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

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 ≈ 19 s

Animation sped up ~4× compared to reality.

  • Chieti
    47 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Pescara
    61 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • Montesilvano
    62 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • L'Aquila
    67 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 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
1.1 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 (M2.6, 11 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.6
The mainshock
3 km North-East of Roccaraso
11 years ago · 27 Jul 2015, 05:19
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
12
last 30 days
51 before43 after
this quake
Strongest of the sequence2.6

How often does it happen here?

about every ~13 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 341 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 · 16 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.8
Lazio-Molise earthquake
9 September 1349 · 43 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16546.3
Sorano earthquake
24 July 1654 · 45 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 4 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

1.7
5 km South-East of Pescocostanzo
8 km South-East · 10 km
11 years ago
8 Aug 2015, 07:11
1.9
4 km North-West of Gamberale
11 km East · 11 km
11 years ago
9 Aug 2015, 08:14
0.6
3 km South-East of Pescocostanzo
6 km South-East · 6 km
11 years ago
9 Aug 2015, 10:56
1.5
11 years ago
9 Aug 2015, 12:55
1.8
3 km South-East of Cansano
3 km North · 11 km
11 years ago
9 Aug 2015, 20:19
1.3
4 km North-East of Pescasseroli
21 km South-West · 13 km
11 years ago
10 Aug 2015, 07:37
1.4
0 km East of Pescocostanzo
3 km South-East · 9 km
11 years ago
6 Aug 2015, 13:50
1.3
4 km North-East of Pescasseroli
21 km South-West · 10 km
11 years ago
10 Aug 2015, 10:06
0.9
11 years ago
6 Aug 2015, 07:14
1.2
3 km West of Barrea
22 km South-West · 8 km
11 years ago
10 Aug 2015, 18:10

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).