All earthquakes
1.6
very light
EARTHQUAKE DETAILS

M1.6 earthquake · 4 km South of San Mauro Marchesato (KR)

10 years ago · 27 Mar 2016, 21:18

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 74% of Italian events in the past year

Where

4 km South of San Mauro MarchesatoEarthquakes 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

5 events
Magnitude:lightweakmoderatestrong

The energy released

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

3.8kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×126 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 ≈ 18 s

Animation sped up ~3× compared to reality.

  • Crotone
    14 km from the epicentre
    first tremor in ~3 s
    main shaking in ~4 s
  • Catanzaro
    35 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Lamezia Terme
    58 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Cosenza
    63 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 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

6 km
shallow

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?

Foreshock

In hindsight it was a foreshock: 10 years ago the same area had a stronger quake (M1.8). This can only be said after the fact — it was not predictable beforehand.

1.8
The mainshock
4 km North-West of Cutro
10 years ago · 16 Apr 2016, 22:05
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
1
last 30 days
1 before3 after
this quake
Strongest of the sequence1.8

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: 666 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 · 28 km from here
XCompletely destructive: most buildings are destroyed.
18326.7
Crotonese earthquake
8 March 1832 · 4 km from here
XCompletely destructive: most buildings are destroyed.
16266.1
Calabria centrale earthquake
4 April 1626 · 48 km from here
XCompletely destructive: most buildings are destroyed.
17445.7
Sila Piccola earthquake
21 March 1744 · 14 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 13 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

1.0
3 km South of San Mauro Marchesato
1 km North-West · 7 km
10 years ago
28 Mar 2016, 04:20
1.8
4 km North-West of Cutro
3 km South · 7 km
10 years ago
16 Apr 2016, 22:05
1.6
4 km North-West of Cotronei
28 km North-West · 18 km
10 years ago
21 Apr 2016, 16:12
1.3
1 km North of Petronà
19 km West · 10 km
10 years ago
26 Feb 2016, 21:39

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).