All earthquakes
0.7
very light
EARTHQUAKE DETAILS

M0.7 earthquake · 4 km South of Roccaraso (AQ)

9 years ago · 30 Jul 2017, 04:55

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 11% of Italian events in the past year

Where

4 km South of RoccarasoEarthquakes 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

15 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 ×2,818 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 ≈ 23 s

Animation sped up ~4× compared to reality.

  • Chieti
    61 km from the epicentre
    first tremor in ~10 s
    main shaking in ~18 s
  • Pescara
    74 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 s
  • Montesilvano
    76 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 s
  • Caserta
    78 km from the epicentre
    first tremor in ~13 s
    main shaking in ~23 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

10 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 (M3.2, 9 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.2
The mainshock
2 km South of Campo di Giove
9 years ago · 1 Jul 2017, 21:12
Activity in the area right now (30 km radius)
1
last 24 hours
9
last 7 days
24
last 30 days
6 before8 after
this quake
Strongest of the sequence3.2

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: 384 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 · 31 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.8
Lazio-Molise earthquake
9 September 1349 · 30 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18056.7
Molise earthquake
26 July 1805 · 47 km from here
XCompletely destructive: most buildings are destroyed.
16546.3
Sorano earthquake
24 July 1654 · 38 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

0.9
2 km East of Scontrone
6 km South · 19 km
9 years ago
2 Aug 2017, 16:52
0.8
9 years ago
7 Aug 2017, 08:18
0.8
9 years ago
21 Jul 2017, 00:17
1.4
1 km South-East of Pesche
28 km South-East · 15 km
9 years ago
20 Jul 2017, 12:06
1.1
2 km South-East of Barrea
10 km South-West · 17 km
9 years ago
16 Jul 2017, 09:45
2.3
2 km North-East of Montaquila
27 km South · 10 km
9 years ago
13 Aug 2017, 06:01
1.4
9 years ago
15 Jul 2017, 22:57
1.2
9 years ago
15 Aug 2017, 14:56
1.0
9 years ago
20 Aug 2017, 13:28
1.7
9 years ago
22 Aug 2017, 00:08

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).