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2.1
light
EARTHQUAKE DETAILS

M2.1 earthquake · 24 km West of Ricadi (VV)

11 years ago · 16 Jul 2015, 07:51

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

Stronger than 90% of Italian events in the past year

Where

24 km West of RicadiEarthquakes in the province of Vibo ValentiaEarthquakes 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

18 events
Magnitude:lightweakmoderatestrong

The energy released

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

21kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×22 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 ≈ 37 s

Animation sped up ~7× compared to reality.

  • Messina
    53 km from the epicentre
    first tremor in ~18 s
    main shaking in ~30 s
  • Reggio di Calabria
    63 km from the epicentre
    first tremor in ~19 s
    main shaking in ~32 s
  • Lamezia Terme
    69 km from the epicentre
    first tremor in ~19 s
    main shaking in ~33 s
  • Cosenza
    91 km from the epicentre
    first tremor in ~22 s
    main shaking in ~37 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

92 km
deep
10 times the height of Mount Everest

Being deep, it is felt less at the surface.

in line with the area average (~96 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 (M2.9, 11 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.9
The mainshock
Tirreno Meridionale [Mare]
11 years ago · 27 Jun 2015, 17:00
Activity in the area right now (30 km radius)
1
last 24 hours
3
last 7 days
13
last 30 days
12 before5 after
this quake
Strongest of the sequence2.9

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: 1676 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 · 40 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18946.1
Calabria meridionale earthquake
16 November 1894 · 49 km from here
IXDestructive: many buildings partly or fully collapse.
19285.9
Calabria centro-meridionale earthquake
7 March 1928 · 31 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
20065.8
Tirreno meridionale earthquake
26 October 2006 · 20 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 31 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

2.0
Tirreno Meridionale [Mare]
23 km South-West · 127 km
11 years ago
15 Jul 2015, 11:33
1.8
23 km North of Villafranca Tirrena
29 km South-West · 124 km
11 years ago
14 Jul 2015, 03:03
2.2
Tirreno Meridionale [Mare]
25 km South-West · 121 km
11 years ago
21 Jul 2015, 12:14
2.3
Tirreno Meridionale [Mare]
19 km West · 211 km
11 years ago
10 Jul 2015, 15:18
2.2
25 km North-West of Ricadi
11 km North-East · 158 km
11 years ago
10 Jul 2015, 09:56
1.9
Tirreno Meridionale [Mare]
22 km South-West · 136 km
11 years ago
23 Jul 2015, 04:06
2.1
23 km West of Ricadi
7 km South · 153 km
11 years ago
23 Jul 2015, 04:38
2.2
Costa Calabra sud-occidentale (Catanzaro, Vibo Valentia, Reggio di Calabria)
23 km North-East · 167 km
11 years ago
4 Jul 2015, 17:03
1.9
11 years ago
2 Jul 2015, 08:34
1.9
Tirreno Meridionale [Mare]
27 km South-West · 123 km
11 years ago
30 Jun 2015, 20:04

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).