All earthquakes
3.3
weak
EARTHQUAKE DETAILS

Golfo di Policastro (Salerno, Potenza)

96 months ago · 28 Sept, 20:58

A weak earthquake, felt by some of the population. Being deep, it is felt less at the surface.

Stronger than 99% of Italian events in the past year

Where

Golfo di Policastro (Salerno, Potenza)Earthquakes in the province of SalernoEarthquakes in Campania

Epicentre at sea

The epicentre is at sea: for the same magnitude, the shaking is felt less on land, because the energy fades along the way before reaching the coast.

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.

1.3tof TNT equivalent
5.6 lightning bolts
M3
×2.8 the energy of a magnitude 3 earthquake
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 ≈ 95 s

Animation sped up ~18× compared to reality.

  • Corigliano-Rossano
    89 km from the epicentre
    first tremor in ~55 s
    main shaking in ~94 s
  • Cosenza
    94 km from the epicentre
    first tremor in ~55 s
    main shaking in ~94 s
  • Battipaglia
    96 km from the epicentre
    first tremor in ~55 s
    main shaking in ~95 s
  • Potenza
    100 km from the epicentre
    first tremor in ~55 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

317 km
deep
36 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~48 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
0
last 7 days
9
last 30 days
0 before2 after
this quake
Strongest of the sequence3.0

How often does it happen here?

about every ~2 months

Within 50 km of this epicentre, a magnitude ≥ 3 earthquake has occurred on average this often: 57 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.

19775.9
Golfo di Policastro earthquake
30 December 1977 · 19 km from here
18365.9
Appennino lucano earthquake
20 November 1836 · 47 km from here
IXDestructive: many buildings partly or fully collapse.
18315.5
Appennino lucano earthquake
2 January 1831 · 43 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18585.4
Campania meridionale earthquake
7 March 1858 · 37 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Rimendiello-Mormanno

The epicentre lies about 48 km from Rimendiello-Mormanno, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.6between 1 and 12 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

1.0
5 km South of Sapri
30 km North-East · 17 km
96 months ago
8 Oct, 11:50
3.0
11 km South-East of San Giovanni a Piro
18 km North-East · 297 km
96 months ago
18 Oct, 20:34

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