All earthquakes
1.8
very light
EARTHQUAKE DETAILS

M1.8 earthquake · 3 km South-East of Roccaraso (AQ)

5 years ago · 22 Jan 2021, 14:01

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 82% of Italian events in the past year

Where

3 km South-East 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

13 events
Magnitude:lightweakmoderatestrong

The energy released

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

7.6kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×63 its energy
M1this quakeM3

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
    60 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Pescara
    73 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Montesilvano
    75 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 s
  • L'Aquila
    79 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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 5 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
5
last 24 hours
9
last 7 days
24
last 30 days
7 before5 after
this quake
Strongest of the sequence1.8

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: 377 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 · 29 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.8
Lazio-Molise earthquake
9 September 1349 · 32 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 · 40 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 lies about 2 km from Borbona-L'Aquila-Aremogna, one of the seismic structures mapped by INGV geologists.

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

1.7
3 km South-West of Pacentro
26 km North-West · 10 km
5 years ago
22 Jan 2021, 00:13
1.0
4 km South-East of Carovilli
24 km South-East · 3 km
5 years ago
20 Jan 2021, 11:13
1.7
5 km South of Palena
13 km North · 17 km
5 years ago
27 Jan 2021, 06:54
1.4
5 years ago
12 Jan 2021, 12:40
1.2
2 km East of Villa Latina
29 km South-West · 7 km
5 years ago
9 Jan 2021, 18:24
1.6
2 km East of Villa Latina
29 km South-West · 8 km
5 years ago
9 Jan 2021, 13:41
1.0
5 years ago
4 Feb 2021, 21:03
1.7
5 years ago
8 Jan 2021, 01:03
1.6
5 years ago
7 Jan 2021, 01:02
1.1
5 years ago
8 Feb 2021, 02:08

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).