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2.6
light
EARTHQUAKE DETAILS

M2.6 earthquake · 14 km East of Bellaria-Igea Marina (RN)

5 years ago · 22 Nov 2020, 11:35

A light earthquake, rarely felt by people. Being deep, it is felt less at the surface.

Stronger than 96% of Italian events in the past year

Where

14 km East of Bellaria-Igea MarinaEarthquakes in the province of RiminiEarthquakes in Emilia-Romagna

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

4 events
Magnitude:lightweakmoderatestrong

The energy released

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

120kgof TNT equivalent
Less than the energy of a lightning bolt
M3
A magnitude 3 earthquake releases ×4 its energy
M2this quakeM4

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.

  • Rimini
    17 km from the epicentre
    first tremor in ~7 s
    main shaking in ~11 s
  • Cesena
    33 km from the epicentre
    first tremor in ~8 s
    main shaking in ~14 s
  • Pesaro
    38 km from the epicentre
    first tremor in ~9 s
    main shaking in ~15 s
  • Ravenna
    43 km from the epicentre
    first tremor in ~9 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

35 km
deep
4 times the height of Mount Everest

Being deep, it is felt less at the surface.

deeper than the area average (~23 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?

Isolated quake

In the 30 days around this event no other quakes were recorded within 30 km: a one-off episode, very common in Italy.

Activity in the area right now (30 km radius)
0
last 24 hours
0
last 7 days
3
last 30 days
1 before2 after
this quake
Strongest of the sequence2.5

How often does it happen here?

about every ~49 days

Within 50 km of this epicentre, a magnitude ≥ 2.5 earthquake has occurred on average this often: 87 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.

19165.8
Riminese earthquake
16 August 1916 · 19 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
19165.8
Riminese earthquake
17 May 1916 · 12 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
18755.7
Costa romagnola earthquake
17 March 1875 · 6 km from here
VIIIRuinous: partial collapses in ordinary buildings, widespread heavy damage.
14835.7
Romagna earthquake
11 August 1483 · 31 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

Riminese offshore

The epicentre lies about 2 km from Riminese offshore, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.2between 3 and 7 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

1.6
5 years ago
8 Nov 2020, 23:42
2.5
9 km North-East of Cervia
23 km North-West · 18 km
5 years ago
9 Dec 2020, 02:02
2.5
5 km South-West of Cervia
29 km West · 19 km
5 years ago
20 Dec 2020, 05:00

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).