All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 2 km North-West of Parenti (CS)

9 years ago · 31 Jul 2017, 13:29

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 39% of Italian events in the past year

Where

2 km North-West of ParentiEarthquakes in the province of CosenzaEarthquakes 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

24 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 ≈ 15 s

Animation sped up ~3× compared to reality.

  • Cosenza
    19 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • Lamezia Terme
    27 km from the epicentre
    first tremor in ~5 s
    main shaking in ~8 s
  • Catanzaro
    34 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Corigliano-Rossano
    51 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 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 (~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 (M2.7, 9 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.7
The mainshock
2 km North of Aprigliano
9 years ago · 28 Jul 2017, 01:12
Activity in the area right now (30 km radius)
0
last 24 hours
2
last 7 days
18
last 30 days
10 before13 after
this quake
Strongest of the sequence2.7

How often does it happen here?

about every ~7 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 655 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 · 19 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.0
Calabria centrale earthquake
28 March 1783 · 43 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
16386.8
Crotonese earthquake
8 June 1638 · 34 km from here
XCompletely destructive: most buildings are destroyed.
11846.8
Valle del Crati earthquake
24 May 1184 · 33 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

Savuto Valley

The epicentre lies about 3 km from Savuto Valley, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 2 and 14 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

1.2
4 km East of Parenti
6 km East · 10 km
9 years ago
30 Jul 2017, 13:35
1.5
3 km North of Lamezia Terme
25 km South-West · 11 km
9 years ago
3 Aug 2017, 18:02
0.9
2 km North-East of Aprigliano
7 km North-East · 13 km
9 years ago
28 Jul 2017, 01:16
2.7
2 km North of Aprigliano
8 km North · 16 km
9 years ago
28 Jul 2017, 01:12
1.9
4 km South of Casali del Manco
11 km North · 39 km
9 years ago
25 Jul 2017, 18:31
1.4
1 km North-East of Cosenza
19 km North-West · 14 km
9 years ago
25 Jul 2017, 07:17
1.4
3 km North-West of Cotronei
22 km East · 19 km
9 years ago
9 Aug 2017, 09:15
1.1
3 km East of Lappano
19 km North-West · 12 km
9 years ago
21 Jul 2017, 21:24
1.2
2 km North of Celico
24 km North · 13 km
9 years ago
12 Aug 2017, 00:35
1.4
2 km South-East of Malito
17 km West · 15 km
9 years ago
19 Jul 2017, 15:03

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).