All earthquakes
1.0
very light
EARTHQUAKE DETAILS

M1.0 earthquake · 24 km East of Siniscola (NU)

1 year ago · 22 Oct 2024, 17:26

A very light earthquake, probably not felt by people. At this depth the shaking is felt, but rarely causes damage.

Stronger than 31% of Italian events in the past year

Where

24 km East of SiniscolaEarthquakes in the province of NuoroEarthquakes in Sardegna

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

1 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.5kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,000 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 ≈ 41 s

Animation sped up ~8× compared to reality.

  • Olbia
    53 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Nuoro
    67 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Sassari
    142 km from the epicentre
    first tremor in ~24 s
    main shaking in ~41 s
  • Oristano
    144 km from the epicentre
    first tremor in ~24 s
    main shaking in ~41 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

10 km
medium depth
1.1 times the height of Mount Everest

At this depth the shaking is felt, but rarely causes damage.

shallower than the area average (~17 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?

Isolated quake

In the 30 days around this event no other quakes were recorded within 30 km: a one-off episode, very common in Italy.

Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
0
last 30 days

No other quakes within 30 km in the 30 days around the event.

How often does it happen here?

about every ~1.7 years

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 7 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.

20004.8
Tirreno centrale earthquake
26 April 2000 · 44 km from here
VRather strong: felt by almost everyone; hanging objects swing.
20044.6
Tirreno centrale earthquake
18 December 2004 · 44 km from here
IVModerate: felt by many indoors; glasses and dishes rattle.
20004.3
Tirreno centrale earthquake
27 June 2000 · 39 km from here
20004.3
Tirreno centrale earthquake
26 April 2000 · 41 km from here

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

The closest seismic structure

Northern Africa offshore - East

The epicentre lies about 211 km from Northern Africa offshore - East, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 8.0between 1 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).

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).