All earthquakes
0.9
very light
EARTHQUAKE DETAILS

M0.9 earthquake · 11 km South-East of Camerota (SA)

8 years ago · 21 Oct 2017, 00:55

A very light earthquake, probably not felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 23% of Italian events in the past year

Where

11 km South-East of CamerotaEarthquakes 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

10 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,413 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 ≈ 28 s

Animation sped up ~5× compared to reality.

  • Battipaglia
    82 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 s
  • Potenza
    85 km from the epicentre
    first tremor in ~14 s
    main shaking in ~25 s
  • Corigliano-Rossano
    94 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 s
  • Salerno
    97 km from the epicentre
    first tremor in ~16 s
    main shaking in ~28 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

14 km
medium depth
1.6 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

shallower than the area average (~29 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?

Aftershock

It is an aftershock: it follows a stronger quake (M3.7, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.7
The mainshock
14 km West of San Nicola Arcella
8 years ago · 18 Oct 2017, 15:10
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
4
last 30 days
1 before8 after
this quake
Strongest of the sequence3.7

How often does it happen here?

about every ~14 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 301 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 · 4 km from here
18365.9
Appennino lucano earthquake
20 November 1836 · 37 km from here
IXDestructive: many buildings partly or fully collapse.
19985.5
Appennino lucano earthquake
9 September 1998 · 46 km from here
VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.
18315.5
Appennino lucano earthquake
2 January 1831 · 34 km from here
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 42 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

3.7
14 km West of San Nicola Arcella
24 km South-East · 280 km
8 years ago
18 Oct 2017, 15:10
1.2
3 km East of Maratea
28 km East · 9 km
8 years ago
29 Oct 2017, 05:28
1.7
5 km North of Maratea
26 km East · 8 km
8 years ago
15 Nov 2017, 04:28
1.4
4 km North-West of Maratea
23 km East · 6 km
8 years ago
15 Nov 2017, 05:00
0.8
3 km East of Torraca
28 km North-East · 8 km
8 years ago
15 Nov 2017, 11:51
0.7
3 km East of Torraca
28 km North-East · 6 km
8 years ago
16 Nov 2017, 02:24
2.0
5 km North-West of Maratea
24 km East · 8 km
8 years ago
18 Nov 2017, 23:59
1.3
3 km North-West of Maratea
24 km East · 9 km
8 years ago
19 Nov 2017, 00:14
1.6
5 km West of Maratea
22 km East · 6 km
8 years ago
19 Nov 2017, 05:12

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).