All earthquakes
4.3
moderate
EARTHQUAKE DETAILS

3 km West of Monteforte Cilento

84 months ago · 21 Sept, 21:55

A moderate earthquake, felt by people in the area. Being deep, it is felt less at the surface.

No. 14 of the year in ItalyStronger than 99% of Italian events in the past yearNo. 5 of the year in Campania

Where

3 km West of Monteforte CilentoEarthquakes in the province of SalernoEarthquakes 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

3 events
Magnitude:lightweakmoderatestrong

The energy released

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

43tof TNT equivalent
178 lightning bolts
M3
×89 the energy of a magnitude 3 earthquake
M3this quakeM5

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 ≈ 95 s

Animation sped up ~18× compared to reality.

  • Battipaglia
    30 km from the epicentre
    first tremor in ~55 s
    main shaking in ~94 s
  • Salerno
    46 km from the epicentre
    first tremor in ~55 s
    main shaking in ~95 s
  • Cava de' Tirreni
    54 km from the epicentre
    first tremor in ~55 s
    main shaking in ~95 s
  • Potenza
    64 km from the epicentre
    first tremor in ~56 s
    main shaking in ~95 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

328 km
deep
37 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~16 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 one aftershock 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
1
last 7 days
3
last 30 days
1 before1 after
this quake
Strongest of the sequence1.4

How often does it happen here?

about every ~5.8 years

Within 50 km of this epicentre, a magnitude ≥ 4 earthquake has occurred on average this often: 2 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.

15616.7
Vallo di Diano earthquake
19 August 1561 · 37 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
15616.3
Vallo di Diano earthquake
31 July 1561 · 38 km from here
IX-XCompletely destructive: most buildings are destroyed.
14666.0
Irpinia-Basilicata earthquake
15 January 1466 · 47 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 50 km from here

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

The closest seismic structure

Irpinia-Agri Valley

The epicentre lies about 37 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
85 months ago
17 Sept, 18:13
0.4
5 km South-West of San Rufo
28 km East · 10 km
84 months ago
29 Sept, 00:02

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).

We use cookies to analyse site traffic and improve your experience.

Privacy PolicyCookie Policy