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2.7
light
EARTHQUAKE DETAILS

M2.7 offshore earthquake

11 years ago · 12 Feb 2015, 08:43

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

Stronger than 97% of Italian events in the past year

Where

Nearest Italian town: Paola (CS)Earthquakes in the province of CosenzaEarthquakes 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

3 events
Magnitude:lightweakmoderatestrong

The energy released

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

169kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×2.8 its energy
M2this quakeM4

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 ≈ 70 s

Animation sped up ~13× compared to reality.

  • Cosenza
    52 km from the epicentre
    first tremor in ~39 s
    main shaking in ~66 s
  • Lamezia Terme
    64 km from the epicentre
    first tremor in ~39 s
    main shaking in ~67 s
  • Corigliano-Rossano
    76 km from the epicentre
    first tremor in ~40 s
    main shaking in ~68 s
  • Catanzaro
    91 km from the epicentre
    first tremor in ~41 s
    main shaking in ~70 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

225 km
deep
25 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~104 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?

Isolated quake

In the 30 days around this event no other quakes were recorded within 30 km: a one-off episode, very common in Italy.

Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
6
last 30 days
1 before1 after
this quake
Strongest of the sequence2.6

How often does it happen here?

about every ~13 days

Within 50 km of this epicentre, a magnitude ≥ 2.5 earthquake has occurred on average this often: 326 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.

11846.8
Valle del Crati earthquake
24 May 1184 · 47 km from here
IXDestructive: many buildings partly or fully collapse.
19945.8
Tirreno meridionale earthquake
5 January 1994 · 45 km from here
IV-VRather strong: felt by almost everyone; hanging objects swing.
18865.6
Cosentino earthquake
6 March 1886 · 45 km from here
VII-VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19985.4
Tirreno meridionale earthquake
18 May 1998 · 48 km from here

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

The closest seismic structure

Crati Valley

The epicentre lies about 47 km from Crati Valley, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.6between 1 and 10 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

2.4
17 km South-West of Bonifati
26 km North · 82 km
11 years ago
4 Mar 2015, 04:42
2.6
9 km South-West of Guardia Piemontese
28 km North-East · 53 km
11 years ago
14 Jan 2015, 10:46

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).