All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 0 km North-West of Spinetoli (AP)

3 years ago · 18 Jun 2023, 04:40

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

Stronger than 39% of Italian events in the past year

Where

0 km North-West of SpinetoliEarthquakes in the province of Ascoli PicenoEarthquakes 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

61 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.7kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×708 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.

  • Teramo
    26 km from the epicentre
    first tremor in ~6 s
    main shaking in ~10 s
  • Montesilvano
    54 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Pescara
    60 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Chieti
    67 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

22 km
medium depth
2.5 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?

Foreshock

In hindsight it was a foreshock: 3 years ago the same area had a stronger quake (M3.0). This can only be said after the fact — it was not predictable beforehand.

3.0
The mainshock
3 km South-West of Castignano
3 years ago · 15 Jul 2023, 08:01
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
5
last 30 days
54 before79 after
this quake
Strongest of the sequence3.0

How often does it happen here?

about every ~1 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 4963 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.

20166.2
Monti della Laga earthquake
24 August 2016 · 49 km from here
XCompletely destructive: most buildings are destroyed.
18735.8
Appennino marchigiano earthquake
12 March 1873 · 48 km from here
IXDestructive: many buildings partly or fully collapse.
19505.7
Gran Sasso earthquake
5 September 1950 · 46 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19435.7
Ascolano earthquake
3 October 1943 · 13 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

Southern Marche

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

estimated maximum magnitude 6.9between 4 and 11 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

0.9
3 km South-West of Servigliano
29 km North-West · 25 km
3 years ago
17 Jun 2023, 05:18
2.0
3 km East of Valle Castellana
27 km South-West · 16 km
3 years ago
16 Jun 2023, 12:15
1.3
3 years ago
15 Jun 2023, 20:09
2.0
4 km East of Valle Castellana
26 km South-West · 14 km
3 years ago
15 Jun 2023, 18:01
1.4
2 km South-East of Comunanza
29 km West · 19 km
3 years ago
15 Jun 2023, 07:08
1.0
3 years ago
14 Jun 2023, 16:16
0.8
5 km East of Valle Castellana
25 km South-West · 17 km
3 years ago
11 Jun 2023, 08:25
0.8
5 km East of Valle Castellana
25 km South-West · 16 km
3 years ago
11 Jun 2023, 08:18
1.3
5 km East of Valle Castellana
25 km South-West · 16 km
3 years ago
11 Jun 2023, 08:14
1.0
5 km East of Valle Castellana
25 km South-West · 15 km
3 years ago
11 Jun 2023, 02:38

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).