All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 3 km North of Strongoli (KR)

8 years ago · 5 Sept 2018, 05:00

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

Stronger than 39% of Italian events in the past year

Where

3 km North of StrongoliEarthquakes 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

14 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×708 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • Crotone
    18 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Catanzaro
    58 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Corigliano-Rossano
    66 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Cosenza
    68 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 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

27 km
medium depth
3 times the height of Mount Everest

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

deeper than the area average (~21 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 (M2.0, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.0
The mainshock
10 km South-East of Crotone
8 years ago · 9 Aug 2018, 14:43
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
2
last 30 days
6 before7 after
this quake
Strongest of the sequence2.0

How often does it happen here?

about every ~8 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 514 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 · 21 km from here
XCompletely destructive: most buildings are destroyed.
18326.7
Crotonese earthquake
8 March 1832 · 24 km from here
XCompletely destructive: most buildings are destroyed.
18366.2
Calabria settentrionale earthquake
25 April 1836 · 43 km from here
XCompletely destructive: most buildings are destroyed.
17445.7
Sila Piccola earthquake
21 March 1744 · 35 km from here
IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Crotone-Rossano

The epicentre lies about 4 km from Crotone-Rossano, one of the seismic structures mapped by INGV geologists.

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

0.8
4 km South-West of Melissa
3 km West · 26 km
8 years ago
5 Sept 2018, 05:21
0.8
1 km East of Casabona
8 km West · 24 km
8 years ago
5 Sept 2018, 04:08
0.8
2 km East of Strongoli
4 km South-East · 27 km
8 years ago
5 Sept 2018, 04:07
1.8
2 km North-West of Casabona
10 km West · 17 km
8 years ago
5 Sept 2018, 06:32
0.7
4 km East of Casabona
6 km West · 24 km
8 years ago
5 Sept 2018, 10:03
1.0
5 km West of Strongoli
5 km South-West · 25 km
8 years ago
11 Sept 2018, 08:20
1.9
8 years ago
23 Aug 2018, 10:25
1.0
15 km East of Cirò Marina
19 km East · 11 km
8 years ago
21 Aug 2018, 03:47
1.0
2 km South-East of Carfizzi
7 km North-West · 22 km
8 years ago
19 Aug 2018, 23:34
0.9
3 km South of Strongoli
6 km South · 23 km
8 years ago
22 Sept 2018, 07:53

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).