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2.7
light
EARTHQUAKE DETAILS

M2.7 earthquake · 3 km South-East of Castelgrande (PZ)

11 years ago · 5 Jun 2015, 10:56

A light earthquake, rarely felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 97% of Italian events in the past yearNo. 4 of the year in Basilicata

Where

3 km South-East of CastelgrandeEarthquakes in the province of PotenzaEarthquakes in Basilicata

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

15 events
Magnitude:lightweakmoderatestrong

The energy released

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

169kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×2.8 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 ≈ 17 s

Animation sped up ~3× compared to reality.

  • Potenza
    32 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Battipaglia
    47 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Salerno
    57 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Avellino
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 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.

in line with the area average (~15 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 6 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
2
last 7 days
12
last 30 days
8 before6 after
this quake
Strongest of the sequence1.9

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: 110 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 · 16 km from here
XCompletely destructive: most buildings are destroyed.
17326.8
Irpinia earthquake
29 November 1732 · 46 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16946.7
Irpinia-Basilicata earthquake
8 September 1694 · 10 km from here
XCompletely destructive: most buildings are destroyed.
15616.7
Vallo di Diano earthquake
19 August 1561 · 25 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.

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

The closest seismic structure

Conza della Campania-Tolve

The epicentre sits above this source area: the deep structure where this area's earthquakes can originate.

estimated maximum magnitude 6.5between 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
4 km West of Muro Lucano
7 km South-West · 10 km
11 years ago
31 May 2015, 04:08
1.5
5 km South of Lacedonia
26 km North · 21 km
11 years ago
27 May 2015, 23:53
1.3
2 km South of Picerno
23 km South-East · 5 km
11 years ago
23 May 2015, 20:01
1.4
11 years ago
23 May 2015, 09:01
1.4
4 km West of Lioni
28 km West · 15 km
11 years ago
23 Jun 2015, 04:30
1.9
0 km North-East of San Gregorio Magno
12 km South-West · 10 km
11 years ago
26 Jun 2015, 15:30
1.4
2 km West of Picerno
21 km South-East · 24 km
11 years ago
28 Jun 2015, 03:19
1.8
2 km North of Ricigliano
11 km South · 15 km
11 years ago
1 Jul 2015, 04:34
1.3
3 km North of Ricigliano
10 km South · 15 km
11 years ago
1 Jul 2015, 09:35
1.5
1 km West of Caposele
21 km West · 11 km
11 years ago
10 May 2015, 09:04

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).