All earthquakes
1.8
very light
EARTHQUAKE DETAILS

M1.8 offshore earthquake

11 years ago · 7 Jun 2015, 23:09

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

Stronger than 82% of Italian events in the past year

Where

Nearest Italian town: Ricadi (VV)Earthquakes in the province of Vibo ValentiaEarthquakes in Calabria

Epicentre at sea

The epicentre is at sea: for the same magnitude, the shaking is felt less on land, because the energy fades along the way before reaching the coast.

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.

7.6kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×63 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 ≈ 58 s

Animation sped up ~11× compared to reality.

  • Messina
    52 km from the epicentre
    first tremor in ~31 s
    main shaking in ~54 s
  • Reggio di Calabria
    64 km from the epicentre
    first tremor in ~32 s
    main shaking in ~55 s
  • Lamezia Terme
    73 km from the epicentre
    first tremor in ~32 s
    main shaking in ~56 s
  • Cosenza
    93 km from the epicentre
    first tremor in ~34 s
    main shaking in ~58 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

180 km
deep
20 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~102 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 (M4.5, 11 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

4.5
The mainshock
Tirreno Meridionale [Mare]
11 years ago · 9 May 2015, 10:22
Activity in the area right now (30 km radius)
2
last 24 hours
5
last 7 days
14
last 30 days
14 before9 after
this quake
Strongest of the sequence4.5

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: 1705 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.

19057.0
Calabria centrale earthquake
8 September 1905 · 43 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19786.0
Golfo di Patti earthquake
15 April 1978 · 50 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19285.9
Calabria centro-meridionale earthquake
7 March 1928 · 35 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
20065.8
Tirreno meridionale earthquake
26 October 2006 · 17 km from here

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

The closest seismic structure

Bagnara-Bovalino

The epicentre lies about 32 km from Bagnara-Bovalino, one of the seismic structures mapped by INGV geologists.

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

2.1
25 km North of Villafranca Tirrena
30 km South-West · 115 km
11 years ago
5 Jun 2015, 21:29
2.1
19 km West of Ricadi
11 km East · 159 km
11 years ago
11 Jun 2015, 02:21
2.2
Tirreno Meridionale [Mare]
15 km North · 174 km
11 years ago
4 Jun 2015, 01:16
1.8
Tirreno Meridionale [Mare]
22 km North-West · 166 km
11 years ago
1 Jun 2015, 02:17
1.7
Isole Eolie (Messina)
15 km North-West · 209 km
11 years ago
31 May 2015, 01:52
1.9
Tirreno Meridionale [Mare]
30 km North · 85 km
11 years ago
17 Jun 2015, 04:59
2.2
Tirreno Meridionale [Mare]
14 km South · 146 km
11 years ago
19 Jun 2015, 03:48
2.1
24 km North-West of Tropea
16 km North-East · 162 km
11 years ago
26 May 2015, 13:41
2.1
Tirreno Meridionale [Mare]
24 km North · 170 km
11 years ago
26 May 2015, 00:36
2.4
Costa Calabra sud-occidentale (Catanzaro, Vibo Valentia, Reggio di Calabria)
24 km North-East · 104 km
11 years ago
21 Jun 2015, 11:56

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).