All earthquakes
1.2
very light
EARTHQUAKE DETAILS

M1.2 earthquake · 7 km South of San Mauro Forte (MT)

10 years ago · 30 Sept 2016, 16:40

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

Stronger than 48% of Italian events in the past year

Where

7 km South of San Mauro ForteEarthquakes in the province of MateraEarthquakes in Basilicata

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

3 events
Magnitude:lightweakmoderatestrong

The energy released

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

1.0kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×501 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.

  • Matera
    43 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Potenza
    49 km from the epicentre
    first tremor in ~9 s
    main shaking in ~16 s
  • Altamura
    53 km from the epicentre
    first tremor in ~10 s
    main shaking in ~17 s
  • Bitonto
    77 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

27 km
medium depth
3 times the height of Mount Everest

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

deeper than the area average (~14 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: 9 years ago the same area had a stronger quake (M1.4). This can only be said after the fact — it was not predictable beforehand.

1.4
The mainshock
2 km West of Campomaggiore
9 years ago · 26 Oct 2016, 17:10
Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
6
last 30 days
1 before1 after
this quake
Strongest of the sequence1.4

How often does it happen here?

about every ~19 days

Within 50 km of this epicentre, a magnitude ≥ 2 earthquake has occurred on average this often: 222 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.

18577.1
Basilicata earthquake
16 December 1857 · 38 km from here
XICatastrophic: very few buildings remain standing; landslides and ground cracks.
12735.8
Potenza earthquake
18 December 1273 · 48 km from here
VIII-IXDestructive: many buildings partly or fully collapse.
18265.7
Potentino earthquake
1 February 1826 · 48 km from here
IXDestructive: many buildings partly or fully collapse.
19985.5
Appennino lucano earthquake
9 September 1998 · 49 km from here
VIIVery strong: hard to stand; chimneys and roof tiles fall, serious damage to weaker buildings.

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

The closest seismic structure

Baragiano-Palagianello

The epicentre lies about 27 km from Baragiano-Palagianello, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 7.4between 13 and 22 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

1.3
6 km South-West of Miglionico
21 km North-East · 11 km
10 years ago
14 Sept 2016, 01:22
1.4
2 km West of Campomaggiore
26 km North-West · 35 km
9 years ago
26 Oct 2016, 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).