All earthquakes
1.0
very light
EARTHQUAKE DETAILS

M1.0 earthquake · 1 km West of Chianche (AV)

10 years ago · 13 Nov 2015, 00:31

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 31% of Italian events in the past year

Where

1 km West of ChiancheEarthquakes in the province of AvellinoEarthquakes in Campania

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

5 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 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 ≈ 11 s

Animation sped up ~2× compared to reality.

  • Benevento
    12 km from the epicentre
    first tremor in ~3 s
    main shaking in ~4 s
  • Avellino
    14 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Acerra
    34 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Scafati
    38 km from the epicentre
    first tremor in ~7 s
    main shaking in ~11 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 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 (~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?

Foreshock

In hindsight it was a foreshock: 10 years ago the same area had a stronger quake (M1.8). This can only be said after the fact — it was not predictable beforehand.

1.8
The mainshock
1 km North-East of Monteforte Irpino
10 years ago · 5 Dec 2015, 11:25
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
5
last 30 days
1 before3 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: 409 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 · 29 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16887.1
Sannio earthquake
5 June 1688 · 33 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19806.8
Irpinia-Basilicata earthquake
23 November 1980 · 48 km from here
XCompletely destructive: most buildings are destroyed.
17326.8
Irpinia earthquake
29 November 1732 · 23 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.

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

The closest seismic structure

Mirabella Eclano-Monteverde

The epicentre lies about 13 km from Mirabella Eclano-Monteverde, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 1 and 16 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
10 years ago
15 Nov 2015, 03:24
1.4
10 years ago
29 Oct 2015, 12:02
1.8
1 km North-East of Monteforte Irpino
16 km South-West · 10 km
10 years ago
5 Dec 2015, 11:25
1.5
1 km East of Monteforte Irpino
17 km South-West · 10 km
10 years ago
9 Dec 2015, 16:00

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).