All earthquakes
2.7
light
EARTHQUAKE DETAILS

M2.7 earthquake · 6 km South-West of Canicattini Bagni (SR)

9 years ago · 21 Jun 2017, 13:18

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

Stronger than 97% of Italian events in the past year

Where

6 km South-West of Canicattini BagniEarthquakes in the province of SiracusaEarthquakes in Sicilia

How far away could it be felt?

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

  • up to ~2 km · felt only by some, at rest

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

6 events
Magnitude:lightweakmoderatestrong

The energy released

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

169kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×2.8 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 ≈ 14 s

Animation sped up ~3× compared to reality.

  • Modica
    18 km from the epicentre
    first tremor in ~3 s
    main shaking in ~6 s
  • Siracusa
    20 km from the epicentre
    first tremor in ~4 s
    main shaking in ~6 s
  • Ragusa
    32 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Vittoria
    47 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 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 (~18 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 (M2.8, 9 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.8
The mainshock
7 km North of Ispica
9 years ago · 26 May 2017, 18:11
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
17
last 30 days
5 before0 after
this quake
Strongest of the sequence2.8

How often does it happen here?

about every ~3 months

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

16937.3
Sicilia sud-orientale earthquake
11 January 1693 · 16 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
15426.7
Sicilia sud-orientale earthquake
10 December 1542 · 25 km from here
XCompletely destructive: most buildings are destroyed.
11696.5
Sicilia sud-orientale earthquake
4 February 1169 · 25 km from here
XCompletely destructive: most buildings are destroyed.
16936.1
Sicilia sud-orientale earthquake
9 January 1693 · 16 km from here
VIII-IXDestructive: many buildings partly or fully collapse.

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

The closest seismic structure

Monte Lauro

The epicentre lies about 9 km from Monte Lauro, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.0between 3 and 15 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
5 km East of Sortino
18 km North-East · 20 km
9 years ago
15 Jun 2017, 05:08
1.3
4 km East of Carlentini
29 km North · 13 km
9 years ago
12 Jun 2017, 13:08
2.8
7 km North of Ispica
25 km South · 28 km
9 years ago
26 May 2017, 18:11
1.9
6 km South of Noto
24 km South · 2 km
9 years ago
26 May 2017, 17:05
1.4
4 km East of Floridia
15 km North-East · 25 km
9 years ago
26 May 2017, 03:38

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).