All earthquakes
1.9
very light
EARTHQUAKE DETAILS

M1.9 earthquake · 1 km West of Melicuccà (RC)

11 years ago · 15 Aug 2015, 22:14

A very light earthquake, probably not felt by people. Being deep, it is felt less at the surface.

Stronger than 85% of Italian events in the past year

Where

1 km West of MelicuccàEarthquakes in the province of Reggio CalabriaEarthquakes 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

21 events
Magnitude:lightweakmoderatestrong

The energy released

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

11kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×45 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 ≈ 32 s

Animation sped up ~6× compared to reality.

  • Reggio di Calabria
    23 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Messina
    31 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Lamezia Terme
    84 km from the epicentre
    first tremor in ~18 s
    main shaking in ~30 s
  • Catanzaro
    94 km from the epicentre
    first tremor in ~19 s
    main shaking in ~32 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

63 km
deep
7.1 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~44 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: 11 years ago the same area had a stronger quake (M2.5). This can only be said after the fact — it was not predictable beforehand.

2.5
The mainshock
9 km North-West of Villa San Giovanni
11 years ago · 7 Sept 2015, 12:09
Activity in the area right now (30 km radius)
1
last 24 hours
5
last 7 days
17
last 30 days
9 before11 after
this quake
Strongest of the sequence2.5

How often does it happen here?

about every ~3 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 1268 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.

19087.1
Stretto di Messina earthquake
28 December 1908 · 21 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.1
Calabria meridionale earthquake
5 February 1783 · 11 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17836.7
Calabria centrale earthquake
7 February 1783 · 45 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18946.1
Calabria meridionale earthquake
16 November 1894 · 2 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

Bagnara-Bovalino

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

estimated maximum magnitude 7.1between 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

1.6
3 km West of Feroleto della Chiesa
27 km North-East · 6 km
11 years ago
16 Aug 2015, 23:58
1.4
3 km West of Benestare
25 km East · 15 km
11 years ago
10 Aug 2015, 15:05
1.5
5 km South-East of Delianuova
14 km South-East · 14 km
11 years ago
10 Aug 2015, 02:28
1.4
11 years ago
24 Aug 2015, 06:39
2.0
3 km East of Messina
28 km West · 68 km
11 years ago
24 Aug 2015, 17:50
1.4
5 km South of Scido
14 km South-East · 11 km
11 years ago
4 Aug 2015, 07:34
2.1
6 km South-East of Messina
29 km South-West · 8 km
11 years ago
28 Aug 2015, 07:03
1.7
3 km North-West of Scilla
7 km South-West · 19 km
11 years ago
3 Aug 2015, 12:55
1.5
6 km West of Reggio di Calabria
25 km South-West · 10 km
11 years ago
2 Aug 2015, 11:01
1.8
3 km South-East of Scido
14 km South-East · 10 km
11 years ago
1 Aug 2015, 18:07

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).