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2.0
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EARTHQUAKE DETAILS

M2.0 earthquake · 8 km West of Monte Sant'Angelo (FG)

11 years ago · 4 Jun 2015, 19:45

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

Stronger than 88% of Italian events in the past year

Where

8 km West of Monte Sant'AngeloEarthquakes 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

9 events
Magnitude:lightweakmoderatestrong

The energy released

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

15kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×32 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 ≈ 15 s

Animation sped up ~3× compared to reality.

  • Manfredonia
    16 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • San Severo
    34 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Foggia
    36 km from the epicentre
    first tremor in ~6 s
    main shaking in ~11 s
  • Cerignola
    50 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 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
1.1 times the height of Mount Everest

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 (M2.5, 11 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.5
The mainshock
5 km West of Vieste
11 years ago · 31 May 2015, 05:13
Activity in the area right now (30 km radius)
0
last 24 hours
1
last 7 days
8
last 30 days
5 before3 after
this quake
Strongest of the sequence2.5

How often does it happen here?

about every ~8 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 525 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 · 44 km from here
XCompletely destructive: most buildings are destroyed.
17316.3
Tavoliere delle Puglie earthquake
20 March 1731 · 50 km from here
IXDestructive: many buildings partly or fully collapse.
16276.0
Capitanata earthquake
7 August 1627 · 46 km from here
IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

San Marco in Lamis-Mattinata

The epicentre sits above this source area: the deep structure where this area's earthquakes can originate.

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

2.5
5 km West of Vieste
27 km North-East · 10 km
11 years ago
31 May 2015, 05:13
1.6
3 km North-East of Manfredonia
13 km South · 19 km
11 years ago
11 Jun 2015, 06:40
1.6
11 years ago
22 May 2015, 01:12
2.2
11 years ago
21 May 2015, 13:31
1.6
5 km East of San Marco in Lamis
21 km South-West · 11 km
11 years ago
13 May 2015, 21:34
1.8
5 km North-West of Mattinata
14 km North-East · 15 km
11 years ago
27 Jun 2015, 23:10
2.1
12 km North-West of Cagnano Varano
29 km North-West · 5 km
11 years ago
3 Jul 2015, 14:16
2.2
11 years ago
5 May 2015, 23:43

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).