All earthquakes
0.6
very light
EARTHQUAKE DETAILS

M0.6 earthquake · 1 km North-East of Ostra (AN)

3 years ago · 26 Jun 2023, 23:28

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

Stronger than 7% of Italian events in the past year

Where

1 km North-East of OstraEarthquakes in the province of AnconaEarthquakes in Marche

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

28 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.1kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×3,981 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 ≈ 20 s

Animation sped up ~4× compared to reality.

  • Fano
    25 km from the epicentre
    first tremor in ~5 s
    main shaking in ~9 s
  • Ancona
    28 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Pesaro
    37 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Rimini
    68 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 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

18 km
medium depth
2 times the height of Mount Everest

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

deeper than the area average (~12 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 (M2.1, 3 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.1
The mainshock
4 km East of Offagna
3 years ago · 10 Jun 2023, 22:56
Activity in the area right now (30 km radius)
2
last 24 hours
2
last 7 days
17
last 30 days
19 before8 after
this quake
Strongest of the sequence2.1

How often does it happen here?

about every ~5 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 864 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.

17996.2
Appennino marchigiano earthquake
28 July 1799 · 47 km from here
IX-XCompletely destructive: most buildings are destroyed.
17416.2
Fabrianese earthquake
24 April 1741 · 24 km from here
IXDestructive: many buildings partly or fully collapse.
19305.8
Senigallia earthquake
30 October 1930 · 22 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
16905.6
Costa anconetana earthquake
23 December 1690 · 38 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

Pesaro-Senigallia

The epicentre lies about 7 km from Pesaro-Senigallia, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.3between 3 and 8 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
3 km South of Cupramontana
21 km South · 18 km
3 years ago
26 Jun 2023, 15:10
0.6
4 km East of Genga
24 km South-West · 1 km
3 years ago
26 Jun 2023, 14:13
1.5
4 km East of Genga
24 km South-West · 1 km
3 years ago
22 Jun 2023, 12:02
0.4
3 km West of Serra San Quirico
23 km South-West · 1 km
3 years ago
19 Jun 2023, 17:05
1.2
1 km North of Chiaravalle
15 km East · 22 km
3 years ago
18 Jun 2023, 14:54
0.6
3 km East of Genga
25 km South-West · 1 km
3 years ago
6 Jul 2023, 16:10
1.0
3 years ago
11 Jul 2023, 01:18
2.1
4 km East of Offagna
30 km East · 8 km
3 years ago
10 Jun 2023, 22:56
0.4
2 km West of Serra San Quirico
23 km South-West · 1 km
3 years ago
13 Jul 2023, 16:38
2.1
2 km North of Offagna
26 km East · 34 km
3 years ago
14 Jul 2023, 23:12

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).