All earthquakes
1.5
very light
EARTHQUAKE DETAILS

M1.5 earthquake · 21 km West of Falerna (CZ)

8 years ago · 12 Aug 2018, 22:05

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

Stronger than 69% of Italian events in the past year

Where

21 km West of FalernaEarthquakes in the province of CatanzaroEarthquakes 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

12 events
Magnitude:lightweakmoderatestrong

The energy released

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

2.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×178 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 ≈ 27 s

Animation sped up ~5× compared to reality.

  • Lamezia Terme
    30 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Cosenza
    47 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Catanzaro
    58 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Corigliano-Rossano
    86 km from the epicentre
    first tremor in ~16 s
    main shaking in ~27 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

38 km
deep
4.3 times the height of Mount Everest

Being deep, it is felt less at the surface.

shallower than the area average (~52 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: 8 years ago the same area had a stronger quake (M2.8). This can only be said after the fact — it was not predictable beforehand.

2.8
The mainshock
22 km North-West of Tropea
8 years ago · 27 Aug 2018, 21:45
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
8
last 30 days
5 before6 after
this quake
Strongest of the sequence2.8

How often does it happen here?

about every ~5 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 875 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 · 33 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17837.0
Calabria centrale earthquake
28 March 1783 · 50 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
19057.0
Calabria centrale earthquake
8 September 1905 · 17 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.
17836.7
Calabria centrale earthquake
7 February 1783 · 48 km from here
X-XICatastrophic: very few buildings remain standing; landslides and ground cracks.

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

The closest seismic structure

Sant'Eufemia

The epicentre lies about 21 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

1.3
8 km South-West of Falerna
14 km East · 20 km
8 years ago
11 Aug 2018, 22:54
1.7
19 km South-West of Gizzeria
10 km South-East · 42 km
8 years ago
11 Aug 2018, 18:42
2.6
24 km West of Amantea
16 km North-West · 189 km
8 years ago
7 Aug 2018, 20:33
2.3
Tirreno Meridionale [Mare]
22 km West · 179 km
8 years ago
25 Aug 2018, 10:24
2.8
22 km North-West of Tropea
29 km South-West · 107 km
8 years ago
27 Aug 2018, 21:45
1.7
Tirreno Meridionale [Mare]
30 km West · 85 km
8 years ago
30 Aug 2018, 05:13
1.4
18 km South-West of Falerna
7 km South-East · 38 km
8 years ago
2 Sept 2018, 05:56
1.9
Tirreno Meridionale [Mare]
30 km West · 86 km
8 years ago
4 Sept 2018, 07:00
1.4
1 km North-West of Martirano
30 km North-East · 11 km
8 years ago
17 Jul 2018, 06:39
1.7
Costa Calabra nord-occidentale (Cosenza)
26 km North-West · 109 km
8 years ago
16 Jul 2018, 06:19

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).