All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 1 km North-East of Balsorano (AQ)

8 years ago · 8 Mar 2018, 15:08

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 69% of Italian events in the past year

Where

1 km North-East of BalsoranoEarthquakes 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

26 events
Magnitude:lightweakmoderatestrong

The energy released

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

2.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×178 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • L'Aquila
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Tivoli
    71 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Velletri
    71 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Latina
    73 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 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

8 km
shallow

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 (M2.0, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.0
The mainshock
3 km South of San Benedetto dei Marsi
8 years ago · 12 Feb 2018, 18:44
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
8
last 30 days
12 before13 after
this quake
Strongest of the sequence2.0

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: 368 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 · 25 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.8
Lazio-Molise earthquake
9 September 1349 · 39 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16546.3
Sorano earthquake
24 July 1654 · 20 km from here
XCompletely destructive: most buildings are destroyed.
19845.9
Monti della Meta earthquake
7 May 1984 · 41 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

Salto Lake-Ovindoli-Barrea

The epicentre lies about 7 km from Salto Lake-Ovindoli-Barrea, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 1 and 15 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

1.1
1 km West of Campoli Appennino
10 km South-East · 6 km
8 years ago
9 Mar 2018, 15:52
0.7
3 km North-East of Casalattico
23 km South-East · 11 km
8 years ago
6 Mar 2018, 06:04
1.4
1 km South of Campoli Appennino
12 km South-East · 2 km
8 years ago
4 Mar 2018, 13:29
1.7
3 km North-West of Belmonte Castello
28 km South-East · 8 km
8 years ago
17 Mar 2018, 14:55
0.5
1 km East of Sora
7 km South · 9 km
8 years ago
27 Feb 2018, 03:34
1.7
6 km South-West of Alatri
23 km South-West · 11 km
8 years ago
21 Feb 2018, 14:56
0.8
2 km South-East of Lecce nei Marsi
14 km North-East · 10 km
8 years ago
23 Mar 2018, 17:40
0.5
8 years ago
24 Mar 2018, 17:31
0.9
3 km West of Alatri
21 km West · 9 km
8 years ago
19 Feb 2018, 04:15
0.6
5 km South-West of Aielli
27 km North · 9 km
8 years ago
18 Feb 2018, 02:41

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).