All earthquakes
1.6
very light
EARTHQUAKE DETAILS

M1.6 earthquake · 6 km South-East of Manfredonia (FG)

10 years ago · 4 Jul 2016, 15:37

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 74% of Italian events in the past year

Where

6 km South-East of ManfredoniaEarthquakes 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

8 events
Magnitude:lightweakmoderatestrong

The energy released

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

3.8kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×126 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 ≈ 9 s

Animation sped up ~2× compared to reality.

  • Manfredonia
    6 km from the epicentre
    first tremor in ~2 s
    main shaking in ~3 s
  • Foggia
    23 km from the epicentre
    first tremor in ~4 s
    main shaking in ~7 s
  • San Severo
    31 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Cerignola
    32 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 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

9 km
shallow

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

shallower than the area average (~16 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: 10 years ago the same area had a stronger quake (M1.8). This can only be said after the fact — it was not predictable beforehand.

1.8
The mainshock
10 km South-East of San Marco in Lamis
10 years ago · 25 Jul 2016, 07:25
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
10
last 30 days
3 before4 after
this quake
Strongest of the sequence1.8

How often does it happen here?

about every ~12 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 346 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 · 42 km from here
XCompletely destructive: most buildings are destroyed.
16276.7
Capitanata earthquake
30 July 1627 · 48 km from here
XCompletely destructive: most buildings are destroyed.
17316.3
Tavoliere delle Puglie earthquake
20 March 1731 · 31 km from here
IXDestructive: many buildings partly or fully collapse.
13616.0
Subappennino dauno earthquake
17 July 1361 · 45 km from here
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 18 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

1.7
10 years ago
4 Jul 2016, 20:03
1.5
4 km North-East of Foggia
20 km West · 6 km
10 years ago
9 Jul 2016, 12:36
1.5
8 km North-East of Rignano Garganico
27 km North-West · 18 km
10 years ago
22 Jun 2016, 11:59
1.8
10 years ago
25 Jul 2016, 07:25
1.0
4 km West of Manfredonia
9 km North-West · 5 km
10 years ago
26 Jul 2016, 22:19
1.5
6 km South-East of Foggia
25 km South-West · 11 km
10 years ago
6 Jun 2016, 22:55
1.5
6 km South-East of Foggia
23 km South-West · 9 km
10 years ago
6 Jun 2016, 22:55

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).