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2.0
light
EARTHQUAKE DETAILS

M2.0 offshore earthquake

10 years ago · 15 Dec 2015, 20:27

A light earthquake, rarely felt by people. Being deep, it is felt less at the surface.

Stronger than 88% 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

7 events
Magnitude:lightweakmoderatestrong

The energy released

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

15kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×32 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 ≈ 66 s

Animation sped up ~12× compared to reality.

  • Lamezia Terme
    73 km from the epicentre
    first tremor in ~38 s
    main shaking in ~65 s
  • Messina
    75 km from the epicentre
    first tremor in ~38 s
    main shaking in ~65 s
  • Cosenza
    85 km from the epicentre
    first tremor in ~39 s
    main shaking in ~66 s
  • Reggio di Calabria
    88 km from the epicentre
    first tremor in ~39 s
    main shaking in ~66 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

215 km
deep
24 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~141 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 (M3.2, 10 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

3.2
The mainshock
25 km North-West of Tropea
10 years ago · 24 Nov 2015, 12:44
Activity in the area right now (30 km radius)
2
last 24 hours
2
last 7 days
15
last 30 days
5 before1 after
this quake
Strongest of the sequence3.2

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: 1280 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 · 49 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19285.9
Calabria centro-meridionale earthquake
7 March 1928 · 47 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19945.8
Tirreno meridionale earthquake
5 January 1994 · 41 km from here
IV-VRather strong: felt by almost everyone; hanging objects swing.
20065.8
Tirreno meridionale earthquake
26 October 2006 · 12 km from here

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

The closest seismic structure

Sant'Eufemia

The epicentre lies about 53 km from Sant'Eufemia, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 1 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

2.5
16 km North-West of Ricadi
28 km South-East · 87 km
10 years ago
14 Dec 2015, 09:46
2.4
Tirreno Meridionale [Mare]
16 km West · 286 km
10 years ago
1 Jan 2016, 12:28
2.2
Tirreno Meridionale [Mare]
18 km North-East · 29 km
10 years ago
28 Nov 2015, 02:30
3.0
23 km West of Ricadi
23 km South-East · 180 km
10 years ago
25 Nov 2015, 00:33
3.2
25 km North-West of Tropea
26 km East · 112 km
10 years ago
24 Nov 2015, 12:44
1.4
Tirreno Meridionale [Mare]
9 km North-East · 59 km
10 years ago
18 Nov 2015, 23:51

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).