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2.7
light
EARTHQUAKE DETAILS

M2.7 earthquake · 1 km North-East of Arienzo (CE)

7 years ago · 5 Jan 2019, 22:15

A light earthquake, rarely felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 97% of Italian events in the past year

Where

1 km North-East of ArienzoEarthquakes in the province of CasertaEarthquakes in Campania

How far away could it be felt?

An estimate of how far people may have felt this quake.

  • up to ~2 km · felt only by some, at rest
    ≈ 7,000 people live in this area

The coloured rings on the map below show these distances.

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.

169kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×2.8 its energy
M2this quakeM4

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 ≈ 7 s

Animation sped up ~1× compared to reality.

  • Acerra
    13 km from the epicentre
    first tremor in ~2 s
    main shaking in ~4 s
  • Afragola
    19 km from the epicentre
    first tremor in ~3 s
    main shaking in ~6 s
  • Caserta
    20 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • Casoria
    23 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 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

6 km
shallow

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

in line with the area average (~5 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?

Isolated quake

In the 30 days around this event no other quakes were recorded within 30 km: a one-off episode, very common in Italy.

Activity in the area right now (30 km radius)
0
last 24 hours
4
last 7 days
14
last 30 days
4 before0 after
this quake
Strongest of the sequence2.3

How often does it happen here?

about every ~17 days

Within 50 km of this epicentre, a magnitude ≥ 2.5 earthquake has occurred on average this often: 249 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 · 34 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16887.1
Sannio earthquake
5 June 1688 · 28 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17326.8
Irpinia earthquake
29 November 1732 · 46 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17026.6
Sannio-Irpinia earthquake
14 March 1702 · 41 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

Miranda-Apice

The epicentre lies about 29 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

1.7
2 km West of Cautano
14 km North-East · 8 km
7 years ago
21 Dec 2018, 03:53
1.1
4 km East of Massa di Somma
24 km South-West · 0 km
7 years ago
11 Dec 2018, 22:56
2.3
3 km South-East of Solopaca
17 km North-East · 6 km
7 years ago
11 Dec 2018, 12:01
2.0
7 years ago
9 Dec 2018, 13:24

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).