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3.0
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EARTHQUAKE DETAILS

M3.0 earthquake · 2 km North of Mascalucia (CT)

11 years ago · 15 Jul 2015, 18:29

A weak earthquake, felt by some of the population. At only a few km deep the shaking is felt more sharply at the surface.

Stronger than 98% of Italian events in the past year

Where

2 km North of MascaluciaEarthquakes in the province of CataniaEarthquakes in Sicilia

Volcanic area: Mount Etna

Here the ground shakes mostly because of moving magma and underground fluids, not colliding plates: events are typically shallow, frequent and organised in swarms. This activity is constantly monitored by INGV.

How far away could it be felt?

An estimate of how far people may have felt this quake.

  • up to ~10 km · felt only by some, at rest
    ≈ 258,000 people live in this area

The coloured rings on the map below show these distances.

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

33 events
Magnitude:lightweakmoderatestrong

The energy released

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

477kgof TNT equivalent
2.0 lightning bolts
M3
About the same energy as a magnitude 3 earthquake
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 ≈ 23 s

Animation sped up ~4× compared to reality.

  • Acireale
    12 km from the epicentre
    first tremor in ~3 s
    main shaking in ~4 s
  • Catania
    14 km from the epicentre
    first tremor in ~3 s
    main shaking in ~5 s
  • Siracusa
    68 km from the epicentre
    first tremor in ~11 s
    main shaking in ~20 s
  • Modica
    78 km from the epicentre
    first tremor in ~13 s
    main shaking in ~23 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 times the height of Mount Everest

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

in line with the area average (~13 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?

Mainshock

It is the strongest quake of its sequence: so far it has been followed by 13 aftershocks within 30 km. Aftershocks tend to fade in number and strength over time.

Activity in the area right now (30 km radius)
0
last 24 hours
12
last 7 days
29
last 30 days
19 before13 after
this quake
Strongest of the sequence2.2

How often does it happen here?

about every ~24 days

Within 50 km of this epicentre, a magnitude ≥ 3 earthquake has occurred on average this often: 180 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.

15426.7
Sicilia sud-orientale earthquake
10 December 1542 · 43 km from here
XCompletely destructive: most buildings are destroyed.
11696.5
Sicilia sud-orientale earthquake
4 February 1169 · 43 km from here
XCompletely destructive: most buildings are destroyed.
18186.3
Catanese earthquake
20 February 1818 · 9 km from here
IX-XCompletely destructive: most buildings are destroyed.
16985.7
Monti Iblei settentrionali earthquake
1 January 1698 · 41 km from here
VII-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

Gela-Catania

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

estimated maximum magnitude 7.1between 3 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

1.3
8 km West of Sant'Alfio
16 km North · 11 km
11 years ago
16 Jul 2015, 07:19
1.8
4 km West of Sant'Alfio
18 km North · 6 km
11 years ago
16 Jul 2015, 08:40
1.6
5 km East of Acireale
15 km East · 4 km
11 years ago
14 Jul 2015, 03:57
1.4
11 years ago
18 Jul 2015, 22:52
1.7
8 km South of Moio Alcantara
27 km North · 5 km
11 years ago
19 Jul 2015, 11:16
1.3
5 km South-West of Paternò
22 km West · 10 km
11 years ago
10 Jul 2015, 14:51
1.3
1 km South-West of Viagrande
5 km North-East · 7 km
11 years ago
7 Jul 2015, 23:07
2.1
11 years ago
7 Jul 2015, 21:55
1.4
17 km East of Catania
26 km South-East · 25 km
11 years ago
3 Jul 2015, 00:20
1.3
2 km North-West of Maletto
28 km North-West · 11 km
11 years ago
2 Jul 2015, 14:59

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).