All earthquakes
1.7
very light
EARTHQUAKE DETAILS

M1.7 earthquake · 12 km South-East of Crotone (KR)

6 years ago · 3 Apr 2020, 14:40

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 78% of Italian events in the past year

Where

12 km South-East of CrotoneEarthquakes in the province of CrotoneEarthquakes 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

61 events
Magnitude:lightweakmoderatestrong

The energy released

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

5.4kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×89 its energy
M1this quakeM3

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 ≈ 24 s

Animation sped up ~5× compared to reality.

  • Crotone
    12 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Catanzaro
    55 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Lamezia Terme
    80 km from the epicentre
    first tremor in ~13 s
    main shaking in ~23 s
  • Cosenza
    85 km from the epicentre
    first tremor in ~14 s
    main shaking in ~24 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

10 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 (~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?

Aftershock

It is an aftershock: it follows a stronger quake (M4.0, 6 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

4.0
The mainshock
12 km East of Crotone
6 years ago · 3 Apr 2020, 05:52
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
1
last 30 days
31 before39 after
this quake
Strongest of the sequence4.0

How often does it happen here?

about every ~12 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 364 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.

16386.8
Crotonese earthquake
8 June 1638 · 43 km from here
XCompletely destructive: most buildings are destroyed.
18326.7
Crotonese earthquake
8 March 1832 · 25 km from here
XCompletely destructive: most buildings are destroyed.
17445.7
Sila Piccola earthquake
21 March 1744 · 37 km from here
IXDestructive: many buildings partly or fully collapse.
19325.5
Ionio settentrionale earthquake
2 January 1932 · 30 km from here
VIStrong: felt by everyone, many get scared; objects fall, first light damage to buildings.

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

The closest seismic structure

Crotone-Rossano

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

estimated maximum magnitude 7.3between 3 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

2.3
15 km East of Crotone
8 km North-East · 21 km
6 years ago
3 Apr 2020, 14:41
1.2
7 km East of Crotone
6 km North-West · 11 km
6 years ago
3 Apr 2020, 14:47
1.5
8 km South-West of Crotone
13 km West · 29 km
6 years ago
3 Apr 2020, 14:04
1.7
6 km South-East of Crotone
7 km North-West · 10 km
6 years ago
3 Apr 2020, 13:27
3.9
11 km East of Crotone
5 km North · 19 km
6 years ago
3 Apr 2020, 16:18
2.2
13 km East of Crotone
3 km North-East · 11 km
6 years ago
3 Apr 2020, 16:21
2.1
4 km East of Crotone
9 km North-West · 10 km
6 years ago
3 Apr 2020, 16:25
1.8
5 km South-East of Crotone
7 km North-West · 11 km
6 years ago
3 Apr 2020, 16:27
1.3
10 km East of Crotone
6 km North · 10 km
6 years ago
3 Apr 2020, 12:53
1.8
5 km East of Crotone
8 km North-West · 11 km
6 years ago
3 Apr 2020, 16:47

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).