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2.8
light
EARTHQUAKE DETAILS

M2.8 earthquake · 2 km East of Montemarano (AV)

7 years ago · 31 Mar 2019, 19:38

A light earthquake, rarely felt by people. Being deep, it is felt less at the surface.

Stronger than 97% of Italian events in the past year

Where

2 km East of MontemaranoEarthquakes 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

10 events
Magnitude:lightweakmoderatestrong

The energy released

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

239kgof TNT equivalent
1.0 lightning bolt
M3
A magnitude 3 earthquake releases ×2 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 ≈ 97 s

Animation sped up ~18× compared to reality.

  • Avellino
    20 km from the epicentre
    first tremor in ~57 s
    main shaking in ~97 s
  • Salerno
    32 km from the epicentre
    first tremor in ~57 s
    main shaking in ~97 s
  • Benevento
    34 km from the epicentre
    first tremor in ~57 s
    main shaking in ~97 s
  • Battipaglia
    35 km from the epicentre
    first tremor in ~57 s
    main shaking in ~97 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

339 km
deep
38 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~13 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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 4 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
0
last 24 hours
4
last 7 days
11
last 30 days
5 before4 after
this quake
Strongest of the sequence2.6

How often does it happen here?

about every ~39 days

Within 50 km of this epicentre, a magnitude ≥ 2.5 earthquake has occurred on average this often: 109 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.

19806.8
Irpinia-Basilicata earthquake
23 November 1980 · 22 km from here
XCompletely destructive: most buildings are destroyed.
17326.8
Irpinia earthquake
29 November 1732 · 18 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16946.7
Irpinia-Basilicata earthquake
8 September 1694 · 32 km from here
XCompletely destructive: most buildings are destroyed.
19306.7
Irpinia earthquake
23 July 1930 · 30 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

Irpinia-Agri Valley

The epicentre lies about 10 km from Irpinia-Agri Valley, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.8between 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

1.4
7 years ago
31 Mar 2019, 10:29
0.9
3 km North-East of Senerchia
24 km South-East · 14 km
7 years ago
2 Apr 2019, 01:23
2.6
1 km North of San Sossio Baronia
26 km North-East · 18 km
7 years ago
26 Mar 2019, 00:02
0.9
1 km North-East of San Sossio Baronia
27 km North-East · 14 km
7 years ago
17 Apr 2019, 16:52
1.5
7 years ago
11 Mar 2019, 20:44
1.3
2 km North-West of Caposele
17 km South-East · 14 km
7 years ago
21 Apr 2019, 03:12
2.1
2 km West of Bonito
20 km North · 10 km
7 years ago
8 Mar 2019, 23:46
1.7
7 years ago
7 Mar 2019, 19:59
1.0
7 years ago
27 Apr 2019, 22:23

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).