All earthquakes
1.0
very light
EARTHQUAKE DETAILS

M1.0 earthquake · 0 km North-West of Bonefro (CB)

3 years ago · 12 Aug 2023, 00:42

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 31% of Italian events in the past year

Where

0 km North-West of BonefroEarthquakes in the province of CampobassoEarthquakes in Molise

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.

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 ≈ 22 s

Animation sped up ~4× compared to reality.

  • San Severo
    50 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Benevento
    64 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Foggia
    64 km from the epicentre
    first tremor in ~11 s
    main shaking in ~19 s
  • Manfredonia
    76 km from the epicentre
    first tremor in ~13 s
    main shaking in ~22 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
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?

Foreshock

In hindsight it was a foreshock: 3 years ago the same area had a stronger quake (M1.9). This can only be said after the fact — it was not predictable beforehand.

1.9
The mainshock
2 km South-West of Macchia Valfortore
3 years ago · 30 Aug 2023, 21:52
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
2
last 30 days
4 before3 after
this quake
Strongest of the sequence1.9

How often does it happen here?

about every ~9 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 489 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.

14567.2
Appennino centro-meridionale earthquake
5 December 1456 · 49 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
18056.7
Molise earthquake
26 July 1805 · 44 km from here
XCompletely destructive: most buildings are destroyed.
16276.7
Capitanata earthquake
30 July 1627 · 35 km from here
XCompletely destructive: most buildings are destroyed.
16276.0
Capitanata earthquake
7 August 1627 · 34 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

Ripabottoni-San Severo

The epicentre lies about 1 km from Ripabottoni-San Severo, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.1between 6 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

1.1
2 km East of Bonefro
2 km South-East · 11 km
3 years ago
8 Aug 2023, 18:48
1.7
3 km East of Ripabottoni
7 km South-West · 23 km
3 years ago
5 Aug 2023, 21:37
1.0
3 km East of Casacalenda
6 km North-West · 11 km
3 years ago
30 Jul 2023, 20:55
1.6
1 km South of Bonefro
1 km South-East · 11 km
3 years ago
26 Aug 2023, 00:17
1.9
3 years ago
30 Aug 2023, 21:52
0.8
3 years ago
1 Sept 2023, 00:39
1.1
3 years ago
22 Jul 2023, 17:10

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).