Mw4.4 earthquake in the Fucino Basin

On 28 February, an earthquake of M_W4.4 occurred in the Fucino Basin in Central Italy. The event did not cause any damage and was not widely felt. Such an earthquake is nothing special for this area, but it’s interesting because from 19-24 April the 6th INQUA meeting on paleoseismology will be held in Pescina. The conference will bring together scientists from all around the world to discuss latest developments in active tectonics, paleoseismology and similar topics, and its date and location were chosen to commemorate the devastating Fucino earthquake of 1915. This quake left more than 33,000 people dead and was one of the largest earthquakes to hit the Mediterranean in modern history. It was also subject to a number of paleoseismological studies (see links below).

The recent event shows a normal faulting mechanism as it is expected for the Apennines:

EMSC map with the normal faulting beach ball. Souce: EMSC (http://www.emsc-csem.org/Earthquake/earthquake.php?id=429668#)

The entire region is characterized by a very high seismicity, although most earthquakes are recorded in the surrounding mountain ranges (such as the L’Aquila region further to the north) and the Fucino Basin itself has seen less frequent quakes during the last 30 years.

INGV seismicity map, 1985-2014, and the 28 February Fucino earthquake (white star). Source: INGV (https://ingvterremoti.files.wordpress.com/2015/02/blog_approfondimento_28feb_3.jpg)

However, as the 1915 event and paleoseismology tell us, this does not mean that seismic hazard there would be low. Also, M>6.0 earthquakes did frequently occur in historic times in the region.

INGV seismic hazard map. Source: INGV (https://ingvterremoti.files.wordpress.com/2015/02/blog_approfondimento_28feb.jpg)

Many thanks to Stéphane Baize who brought this earthquake to my attention.

Update (2015-03-02)

Paolo Galli pointed out that the recent M_W4.4 event in fact is quite special for the Fucino Basin, as there is not as much seismicity as in the surroundings and it allowed the INGV to determine a moment tensor solution that fits the 1915 seismic source. Thanks!

Update (2015-03-03)

Salvatore Barba emphasized that according to INGV, the earthquake had a magnitude of Ml 3.9 (M_W4.4) only. Thanks!

References and further reading

• Michetti, A. M., Brunamonte, F., Serva, L., & Vittori, E. (1996). Trench investigations of the 1915 Fucino earthquake fault scarps (Abruzzo, Central Italy): geological evidence of large historical events. Journal of Geophysical Research: Solid Earth (1978–2012), 101(B3), 5921-5936.
• Galadini, F., Galli, P., & Giraudi, C. (1997). Geological investigations of Italian earthquakes: new paleoseismological data from the Fucino Plain (Central Italy). Journal of Geodynamics, 24(1), 87-103.
• Amoruso, A., Crescentini, L., & Scarpa, R. (1998). Inversion of source parameters from near‐and far‐field observations: An application to the 1915 Fucino earthquake, central Apennines, Italy. Journal of Geophysical Research: Solid Earth (1978–2012), 103(B12), 29989-29999.
• Galadini, F., & Galli, P. (1999). The Holocene paleoearthquakes on the 1915 Avezzano earthquake faults (central Italy): implications for active tectonics in the central Apennines. Tectonophysics, 308(1), 143-170.

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