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2.6
light
EARTHQUAKE DETAILS

M2.6 earthquake · 9 km North of Cagnano Varano (FG)

7 years ago · 22 Feb 2019, 22:23

A light earthquake, rarely felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 96% of Italian events in the past year

Where

9 km North of Cagnano VaranoEarthquakes in the province of FoggiaEarthquakes in Puglia

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

6 events
Magnitude:lightweakmoderatestrong

The energy released

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

120kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×4 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 ≈ 21 s

Animation sped up ~4× compared to reality.

  • Manfredonia
    38 km from the epicentre
    first tremor in ~7 s
    main shaking in ~11 s
  • San Severo
    40 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Foggia
    52 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Cerignola
    74 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 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

7 km
shallow

At only a few km deep the shaking is felt more sharply at the surface.

shallower than the area average (~15 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
2
last 7 days
8
last 30 days
0 before5 after
this quake
Strongest of the sequence2.1

How often does it happen here?

about every ~25 days

Within 50 km of this epicentre, a magnitude ≥ 2.5 earthquake has occurred on average this often: 172 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.

16466.7
Gargano earthquake
31 May 1646 · 24 km from here
XCompletely destructive: most buildings are destroyed.
16276.7
Capitanata earthquake
30 July 1627 · 36 km from here
XCompletely destructive: most buildings are destroyed.
16276.0
Capitanata earthquake
7 August 1627 · 36 km from here
IXDestructive: many buildings partly or fully collapse.
16576.0
Capitanata earthquake
29 January 1657 · 34 km from here
IX-XCompletely destructive: most buildings are destroyed.

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

The closest seismic structure

San Marco in Lamis-Mattinata

The epicentre lies about 20 km from San Marco in Lamis-Mattinata, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.0between 0 and 25 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

1.2
7 years ago
4 Mar 2019, 00:13
2.1
7 km South of Carpino
21 km South-East · 20 km
7 years ago
6 Mar 2019, 03:17
1.6
7 km South-West of Carpino
19 km South-East · 21 km
7 years ago
6 Mar 2019, 14:04
1.3
9 km South of Cagnano Varano
18 km South · 22 km
7 years ago
13 Mar 2019, 10:27
1.3
10 km North-East of Lesina
19 km West · 3 km
7 years ago
13 Mar 2019, 21:07

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).