All earthquakes
1.4
very light
EARTHQUAKE DETAILS

M1.4 earthquake · 1 km South-West of Configni (RI)

7 years ago · 2 Dec 2018, 17:31

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 63% of Italian events in the past year

Where

1 km South-West of ConfigniEarthquakes in the province of RietiEarthquakes in Lazio

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

20 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.9kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×251 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 ≈ 16 s

Animation sped up ~3× compared to reality.

  • Terni
    17 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Viterbo
    44 km from the epicentre
    first tremor in ~8 s
    main shaking in ~13 s
  • Guidonia Montecelio
    51 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Tivoli
    54 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 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

At only a few km deep the shaking is felt more sharply at the surface.

in line with the area average (~10 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 (M3.4, 7 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.4
The mainshock
2 km South-East of Montenero Sabino
7 years ago · 6 Nov 2018, 19:50
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
3
last 30 days
9 before10 after
this quake
Strongest of the sequence3.4

How often does it happen here?

about every ~6 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 690 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.

17036.9
Valnerina earthquake
14 January 1703 · 47 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
13496.3
Appennino laziale-abruzzese earthquake
9 September 1349 · 44 km from here
IXDestructive: many buildings partly or fully collapse.
12986.3
Monti Reatini earthquake
1 December 1298 · 27 km from here
XCompletely destructive: most buildings are destroyed.
15996.1
Valnerina earthquake
6 November 1599 · 46 km from here
IXDestructive: many buildings partly or fully collapse.

Source: Parametric Catalogue of Italian Earthquakes CPTI15 (INGV, CC BY 4.0).

The closest seismic structure

Mugello-Citta' di Castello-Leonessa

The epicentre lies about 27 km from Mugello-Citta' di Castello-Leonessa, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 1 and 8 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

1.6
2 km East of San Gemini
21 km North · 8 km
7 years ago
6 Dec 2018, 15:22
1.4
7 years ago
26 Nov 2018, 00:12
2.4
7 years ago
9 Dec 2018, 21:35
1.9
3 km West of Stroncone
6 km North · 11 km
7 years ago
24 Nov 2018, 08:03
1.4
7 years ago
11 Dec 2018, 20:44
1.3
7 years ago
12 Dec 2018, 23:58
1.5
6 km North-West of Stroncone
10 km North · 9 km
7 years ago
13 Dec 2018, 07:57
1.4
4 km East of Cantalice
29 km East · 11 km
7 years ago
14 Dec 2018, 12:36
1.4
7 years ago
19 Nov 2018, 04:29
1.4
3 km East of Polino
29 km North-East · 11 km
7 years ago
19 Dec 2018, 06:16

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).