All earthquakes
1.0
very light
EARTHQUAKE DETAILS

M1.0 earthquake · 3 km North of Albi (CZ)

11 years ago · 25 Apr 2015, 22:16

A very light earthquake, probably not felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 31% of Italian events in the past year

Where

3 km North of AlbiEarthquakes in the province of CatanzaroEarthquakes in Calabria

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

12 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 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 ≈ 12 s

Animation sped up ~2× compared to reality.

  • Catanzaro
    20 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • Lamezia Terme
    30 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Cosenza
    37 km from the epicentre
    first tremor in ~6 s
    main shaking in ~11 s
  • Crotone
    42 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 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

9 km
shallow
1.1 times the height of Mount Everest

At only a few km deep the shaking is felt more sharply at the surface.

shallower than the area average (~18 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 (M2.8, 11 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.8
The mainshock
4 km North-West of Soveria Mannelli
11 years ago · 17 Apr 2015, 02:00
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
15
last 30 days
4 before7 after
this quake
Strongest of the sequence2.8

How often does it happen here?

about every ~6 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 719 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.

16387.1
Calabria centrale earthquake
27 March 1638 · 28 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.0
Calabria centrale earthquake
28 March 1783 · 34 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16386.8
Crotonese earthquake
8 June 1638 · 30 km from here
XCompletely destructive: most buildings are destroyed.
18326.7
Crotonese earthquake
8 March 1832 · 27 km from here
XCompletely destructive: most buildings are destroyed.

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

The closest seismic structure

Ampollino Lake

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

estimated maximum magnitude 7.1between 1 and 15 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

1.5
0 km North of Carpanzano
26 km West · 9 km
11 years ago
25 Apr 2015, 19:49
0.9
6 km East of Aprigliano
17 km North-West · 20 km
11 years ago
24 Apr 2015, 08:38
1.4
4 km East of Pietrafitta
28 km North-West · 7 km
11 years ago
28 Apr 2015, 04:13
2.8
11 years ago
17 Apr 2015, 02:00
1.0
6 km East of Panettieri
8 km North-West · 20 km
11 years ago
5 May 2015, 03:28
2.0
6 km North-East of Panettieri
10 km North-West · 10 km
11 years ago
5 May 2015, 03:50
1.3
5 km South-West of Botricello
25 km South-East · 36 km
11 years ago
5 May 2015, 12:45
1.0
11 years ago
14 Apr 2015, 10:11
1.0
2 km North-East of Feroleto Antico
21 km South-West · 9 km
11 years ago
9 May 2015, 09:57
0.5
4 km North of Cotronei
19 km North-East · 18 km
11 years ago
13 May 2015, 01:59

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).