  14 January 16 January 2 February  14 January 16 January 2 February | |
| Local date | 14 January 1703 (1703-01-14) |
|---|---|
| Magnitude | 6.7–6.2–6.7ML |
| Epicenter | 42°42′N13°04′E / 42.7°N 13.07°E /42.7; 13.07 (first event) |
| Areas affected | Italy |
| Casualties | 10,000 deaths |
The1703 Apennine earthquakes were a sequence of threeearthquakes ofmagnitude ≥6 that occurred in the centralApennines of Italy, over a period of 19 days. Theepicenters were nearNorcia (14 January),Montereale (16 January) andL'Aquila (2 February), showing a southwards progression over about 36 kilometres (22 mi). These events involved all of the known activefaults between Norcia and L'Aquila.[1] A total of about 10,000 people are estimated to have died as a result of these earthquakes,[2] although because of the overlap in areas affected by the three events, casualty numbers remain highly uncertain.
The central part of the Apennines has been characterised byextensional tectonics since thePlioceneepoch (i.e. about the last 5 million years), with most of theactive faults being normal in type and NW-SE trending.[3] The extension is due to theback-arc basin in theTyrrhenian Sea opening faster than theAfrican plate iscolliding with theEurasian plate.[4]
The earthquake occurred at 18:00UTC on 14 January with an estimated magnitude of 6.7.[5] It was caused by movement on an en echelon set of three normal faults, known as the Norcia Fault System.[1]
There was extensive damage in the area around Norcia, withSpoleto andRieti also affected.[6] Modern estimates give a maximumMercalli intensity of XI (Extreme).[7]Ground rupture was observed at several locations and these have been confirmed by modern investigations.[1]
Estimates of the death toll vary from 6,240[8] to 9,761.[5]
The earthquake occurred at 13:30 UTC on 16 January with an estimated magnitude of 6.2.[5] It is thought to have been caused by movement on the Montereale Fault.[1] Damage was recorded in Montereale,Cittareale,Accumoli andAmatrice. Although of lower magnitude than the other two events, this earthquake was still felt in Rome.[6] The estimated intensity for this event is VIII (Severe).[7] No separate casualty figures are available for this event.
The earthquake occurred at 11:05 UTC on 2 February with an estimated magnitude of 6.7.[5] It was caused by movement on the Mt. Marine Fault.[1]
Most of the buildings in L’Aquila were badly damaged or completely destroyed. Damage was reported from as far away as Rome.[6] Modern estimates give a maximum intensity of X (Extreme).[7] The earthquake caused a huge landslide on the Mt. Marine ridge, a large slope failure nearPosta andliquefaction along theAterno River.
Estimates of the death toll vary from 2,500[7] to 5,000.[9]
Details taken from Catalogue of Strong Earthquakes in Italy (461 BC – 1997) and Mediterranean Area (760 B.C. – 1500)[10]
Download coordinates as:
| Name | Date | Time | Coordinates | Magnitude | Intensity |
|---|---|---|---|---|---|
| Norcia | 14 January | 18:00 | 42°42′N13°04′E / 42.70°N 13.07°E /42.70; 13.07 | 6.7 | XI |
| Montereale | 16 January | 13:30 | 42°37′N13°06′E / 42.62°N 13.10°E /42.62; 13.10 | 6.2 | VIII |
| L'Aquila | 2 February | 11:05 | 42°26′N13°18′E / 42.43°N 13.30°E /42.43; 13.30 | 6.7 | X |
Some seismologists interpret these events as related. It has been suggested that the Norcia earthquake led directly to the Montereale event, which had the effect of further loading the fault at Aquila, thus triggering the final event.[1] Such sequential adjacent events are examples ofcoulomb stress transfer.