All earthquakes
0.9
very light
EARTHQUAKE DETAILS

M0.9 earthquake · 1 km West of Busso (CB)

8 years ago · 27 Feb 2018, 20:27

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 23% of Italian events in the past year

Where

1 km West of BussoEarthquakes in the province of CampobassoEarthquakes in Molise

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

8 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,413 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • Benevento
    50 km from the epicentre
    first tremor in ~8 s
    main shaking in ~15 s
  • Caserta
    54 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Acerra
    67 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Aversa
    71 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

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.

shallower than the area average (~14 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 (M1.8, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.8
The mainshock
2 km North-West of Ripabottoni
8 years ago · 30 Jan 2018, 09:49
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
6
last 30 days
4 before3 after
this quake
Strongest of the sequence1.8

How often does it happen here?

about every ~8 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 555 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.

14567.2
Appennino centro-meridionale earthquake
5 December 1456 · 32 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16887.1
Sannio earthquake
5 June 1688 · 31 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18056.7
Molise earthquake
26 July 1805 · 10 km from here
XCompletely destructive: most buildings are destroyed.
19626.2
Irpinia earthquake
21 August 1962 · 50 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

Miranda-Apice

The epicentre lies about 6 km from Miranda-Apice, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 1 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

1.1
3 km East of Baranello
6 km South-East · 10 km
8 years ago
9 Mar 2018, 14:33
0.9
3 km East of Miranda
25 km West · 11 km
8 years ago
16 Feb 2018, 20:02
1.1
8 years ago
26 Mar 2018, 03:58
0.9
3 km East of Pietraroja
24 km South · 10 km
8 years ago
31 Jan 2018, 01:28
1.8
2 km North-West of Ripabottoni
26 km North-East · 11 km
8 years ago
30 Jan 2018, 09:49
0.9
2 km North-East of San Polo Matese
10 km South-West · 11 km
8 years ago
28 Jan 2018, 23:33
1.3
0 km South-West of San Polo Matese
13 km South-West · 8 km
8 years ago
29 Mar 2018, 20:58

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).