All earthquakes
0.8
very light
EARTHQUAKE DETAILS

M0.8 earthquake · 3 km South-West of Mergo (AN)

7 years ago · 20 Sept 2019, 06:25

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

Stronger than 17% of Italian events in the past year

Where

3 km South-West of MergoEarthquakes 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

61 events
Magnitude:lightweakmoderatestrong

The energy released

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

0.2kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×1,995 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 ≈ 16 s

Animation sped up ~3× compared to reality.

  • Fano
    39 km from the epicentre
    first tremor in ~7 s
    main shaking in ~12 s
  • Ancona
    41 km from the epicentre
    first tremor in ~7 s
    main shaking in ~13 s
  • Pesaro
    47 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Foligno
    55 km from the epicentre
    first tremor in ~10 s
    main shaking in ~16 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

15 km
medium depth
1.7 times the height of Mount Everest

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

deeper than the area average (~10 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 (M2.2, 7 years ago) in the same area. Aftershocks are normal after an earthquake and tend to fade over time.

2.2
The mainshock
3 km East of Scheggia e Pascelupo
7 years ago · 2 Sept 2019, 03:07
Activity in the area right now (30 km radius)
4
last 24 hours
11
last 7 days
82
last 30 days
37 before46 after
this quake
Strongest of the sequence2.2

How often does it happen here?

about every ~2 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 2498 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.

17816.5
Cagliese earthquake
3 June 1781 · 43 km from here
XCompletely destructive: most buildings are destroyed.
17516.4
Appennino umbro-marchigiano earthquake
27 July 1751 · 33 km from here
XCompletely destructive: most buildings are destroyed.
12796.2
Appennino umbro-marchigiano earthquake
30 April 1279 · 42 km from here
XCompletely destructive: most buildings are destroyed.
17996.2
Appennino marchigiano earthquake
28 July 1799 · 31 km from here
IX-XCompletely destructive: most buildings are destroyed.

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

The closest seismic structure

Urbino-Camerino

The epicentre lies about 3 km from Urbino-Camerino, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.9between 3 and 9 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
4 km East of Genga
3 km South-West · 1 km
7 years ago
20 Sept 2019, 16:43
1.1
7 years ago
18 Sept 2019, 16:47
0.9
4 km North-East of Sigillo
22 km West · 11 km
7 years ago
22 Sept 2019, 10:24
0.8
7 years ago
17 Sept 2019, 16:34
0.3
2 km East of Costacciaro
24 km West · 12 km
7 years ago
22 Sept 2019, 23:38
1.1
5 km North of San Severino Marche
21 km South-East · 1 km
7 years ago
17 Sept 2019, 12:11
0.6
4 km North-East of Gualdo Tadino
29 km South-West · 11 km
7 years ago
23 Sept 2019, 03:43
0.8
3 km West of Sassoferrato
18 km West · 13 km
7 years ago
17 Sept 2019, 07:55
1.7
2 km West of Sassoferrato
16 km West · 44 km
7 years ago
17 Sept 2019, 05:14
0.6
7 years ago
23 Sept 2019, 16:20

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).