All earthquakes
1.1
very light
EARTHQUAKE DETAILS

M1.1 earthquake · 2 km North of Monte San Giusto (MC)

4 years ago · 26 Aug 2022, 00:29

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

2 km North of Monte San GiustoEarthquakes in the province of MacerataEarthquakes 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

43 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 ≈ 23 s

Animation sped up ~4× compared to reality.

  • Ancona
    38 km from the epicentre
    first tremor in ~7 s
    main shaking in ~13 s
  • Teramo
    66 km from the epicentre
    first tremor in ~12 s
    main shaking in ~20 s
  • Foligno
    70 km from the epicentre
    first tremor in ~12 s
    main shaking in ~21 s
  • Fano
    79 km from the epicentre
    first tremor in ~14 s
    main shaking in ~23 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 (~11 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: 4 years ago the same area had a stronger quake (M2.4). This can only be said after the fact — it was not predictable beforehand.

2.4
The mainshock
2 km South-East of Loro Piceno
4 years ago · 11 Sept 2022, 15:21
Activity in the area right now (30 km radius)
0
last 24 hours
3
last 7 days
13
last 30 days
23 before19 after
this quake
Strongest of the sequence2.4

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: 3751 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 · 35 km from here
IX-XCompletely destructive: most buildings are destroyed.
18735.8
Appennino marchigiano earthquake
12 March 1873 · 33 km from here
IXDestructive: many buildings partly or fully collapse.
19435.7
Ascolano earthquake
3 October 1943 · 35 km from here
IXDestructive: many buildings partly or fully collapse.
16905.6
Costa anconetana earthquake
23 December 1690 · 33 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

Southern Marche

The epicentre lies about 1 km from Southern Marche, one of the seismic structures mapped by INGV geologists.

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

1.0
2 km South-East of Ripe San Ginesio
21 km South-West · 21 km
4 years ago
25 Aug 2022, 11:33
0.9
2 km West of Sant'Angelo in Pontano
23 km South-West · 24 km
4 years ago
25 Aug 2022, 02:55
0.7
4 years ago
27 Aug 2022, 00:20
1.4
1 km North of Sant'Angelo in Pontano
21 km South-West · 20 km
4 years ago
24 Aug 2022, 20:42
1.1
2 km West of Sant'Angelo in Pontano
23 km South-West · 23 km
4 years ago
24 Aug 2022, 20:23
1.1
2 km North of Sant'Angelo in Pontano
21 km South-West · 24 km
4 years ago
24 Aug 2022, 20:22
1.6
1 km West of Sant'Angelo in Pontano
22 km South-West · 23 km
4 years ago
24 Aug 2022, 20:21
2.1
2 km West of Sant'Angelo in Pontano
23 km South-West · 22 km
4 years ago
24 Aug 2022, 20:21
1.3
4 years ago
23 Aug 2022, 13:04
1.4
4 years ago
22 Aug 2022, 02:10

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).