All earthquakes
1.3
very light
EARTHQUAKE DETAILS

M1.3 earthquake · 6 km West of Zapponeta (FG)

8 years ago · 11 Jun 2018, 03:55

A very light earthquake, probably not felt by people. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 55% of Italian events in the past year

Where

6 km West of ZapponetaEarthquakes 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

5 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.3kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×355 its energy
M0this quakeM2

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 ≈ 10 s

Animation sped up ~2× compared to reality.

  • Manfredonia
    14 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Foggia
    20 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • Cerignola
    22 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • San Severo
    33 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 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

6 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?

Aftershock

It is an aftershock: it follows a stronger quake (M1.7, 8 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

1.7
The mainshock
10 km West of Zapponeta
8 years ago · 31 May 2018, 00:05
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
7
last 30 days
2 before2 after
this quake
Strongest of the sequence1.7

How often does it happen here?

about every ~16 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 271 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.

17316.3
Tavoliere delle Puglie earthquake
20 March 1731 · 21 km from here
IXDestructive: many buildings partly or fully collapse.
13616.0
Subappennino dauno earthquake
17 July 1361 · 37 km from here
XCompletely destructive: most buildings are destroyed.
16576.0
Capitanata earthquake
29 January 1657 · 49 km from here
IX-XCompletely destructive: most buildings are destroyed.
18755.9
Gargano earthquake
6 December 1875 · 30 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.

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

The closest seismic structure

Castelluccio dei Sauri-Trani

The epicentre lies about 18 km from Castelluccio dei Sauri-Trani, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.3between 11 and 23 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

1.5
11 km North-East of Cerignola
19 km South-East · 8 km
8 years ago
21 Jun 2018, 02:47
1.7
10 km West of Zapponeta
6 km North-West · 7 km
8 years ago
31 May 2018, 00:05
1.2
7 km South-East of Rignano Garganico
27 km North-West · 5 km
8 years ago
23 Jun 2018, 20:06
1.0
8 years ago
21 May 2018, 09:58

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).