All earthquakes
0.7
very light
EARTHQUAKE DETAILS

M0.7 earthquake · 3 km East of Castelnuovo Cilento (SA)

9 years ago · 25 Mar 2017, 08:57

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

Stronger than 11% of Italian events in the past year

Where

3 km East of Castelnuovo 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

2 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.2kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×2,818 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 ≈ 20 s

Animation sped up ~4× compared to reality.

  • Battipaglia
    48 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Salerno
    63 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Cava de' Tirreni
    70 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Potenza
    70 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 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

11 km
medium depth
1.2 times the height of Mount Everest

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

shallower than the area average (~22 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
0
last 7 days
0
last 30 days
0 before1 after
this quake
Strongest of the sequence0.7

How often does it happen here?

about every ~32 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 134 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 · 46 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19775.9
Golfo di Policastro earthquake
30 December 1977 · 33 km from here
18365.9
Appennino lucano earthquake
20 November 1836 · 48 km from here
IXDestructive: many buildings partly or fully collapse.
18585.4
Campania meridionale earthquake
7 March 1858 · 36 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

Irpinia-Agri Valley

The epicentre lies about 43 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

0.7
4 km South-West of Sanza
24 km East · 21 km
9 years ago
30 Mar 2017, 05:28

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).