A magnitude ML 3.1 earthquake occured in region: 4 km NW Sant'Alfio (CT), on
and geographic coordinates (lat, lon) 37.763, 15.106 at 8 km depth.
The earthquake was located by: Sala Operativa INGV-OE (Catania).
Search earthquakes: Any within 30 km radius
The values of hypocentral coordinates and magnitude may be revised at a later time as more information becomes available.
|Municipality||Region||Distance (km)||Inhabitants||Cumulative Inhabitants|
|Fiumefreddo di Sicilia||CT||10||9623||96546|
|Castiglione di Sicilia||CT||14||3215||105069|
|Francavilla di Sicilia||ME||16||3945||112198|
These maps show the seismicity for different time windows. The earthquake locations reported in these maps are determined in quasi real-time by the personnel on duty in the seismic surveillance center of INGV in Rome. Note that the earthquake source parameters (hypocentral location and magnitude) are the best estimates obstained with the available data and they are adjourned as additional data become available. The source parameters obtained by the personnel on duty are then revised by the group in charge of the INGV Seismic Bulletin (Bollettino Sismico Italiano dell’INGV).
Seismic hazard maps provide probabilistic estimates of the earthquake ground shaking exceeding a given threshold in a given geographic region within a given time window. Thus, it is not a deterministic prediction - a target that may be never reached given the complexity of the earthquake physical phenomenon - nor of the maximum expected earthquake since this has extremely low probabilities to occur.
In 2004, it was published the seismic hazard map of Italy (http://zonesismiche.mi.ingv.it) that provides a picture of the most hazardous geographic regions. The seismic hazard map of Italy (GdL MPS, 2004; rif. Ordinanza PCM del 28 aprile 2006, n. 3519, All. 1b) provides the 10% probability of exceedance in 50 years of the horizontal acceleration at rock sites (i.e., Vs30>800 m/s; cat. A, 3.2.1 of the D.M. 14.09.2005).
The colours indicate the various values of the ground acceleration that have 10% to be exceeded within 50 years. In general, the colours associated to low values of acceleration refer to areas that are less hazardous and stronger earthquakes repeat less frequently although they may still occur.
These three maps show the results of the analysis using the software ShakeMap designed to provide the level of ground shaking experienced in a region using the data recorded by seismometers and strong motion instruments and seismological information regarding the attenuation of the wavefield with distance and the site characteristics. The Shakemaps are determined for research purposes to provide fast estimates of the level of ground shaking produced by the earthquake. The maps are calculated automatically and adjourned progressively as more data become available. See http://shakemap.rm.ingv.it/ for additional information.
The red star indicates the epicenter. The red triangles show the stations of the INGV Italian National Seismic Network and the blue triangles those of the Nationa Accelerometric Network of the Dipartimento della Protezione Civile.
|Type||Magnitude||Date and Time (UTC)||Latitude||Longitude||Depth (km)||Published time (UTC)||Author||Location ID|
|Sala Operativa INGV-OE (Catania)||89923331|
|Time (UTC)||2021-05-08 18:13:25|
|Depth (km)||9 (from location)|
|Evaluation mode of Origin||manual|
|Evaluation status of Origin||reviewed|
|Version||200 -> SURVEY-INGV-CT|
|Preferred uncertainty description||horizontal uncertainty|
|Semi-major axis of confidence ellipse (meter)|
|Semi-minor axis of confidence ellipse (meter)|
|Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi)|
|Circular confidence region, given by single value of horizontal uncertainty (meter)||500|
|Confidence level of the uncertainty (%)||68|
|Largest azimuthal gap in station distribution as seen from epicenter (degree)||33|
|Number of associated phases, regardless of their use for origin computation||1|
|Number of defining phases||1|
|RMS of the travel time residuals of the arrivals used for the origin computation (sec)||0.23|
|Epicentral distance of station closest to the epicenter (degree)|
|Epicentral distance of station farthest from the epicenter (degree)|
|Number of stations at which the event was observed||0|
|Number of stations from which data was used for origin computation||0|
|Num. used stations|
|Type of magnitude||ML|
|Reference to an origin||89923331|
|Autore||Sala Operativa INGV-OE (Catania)|
|Time of creation (UTC)||2021-05-08 18:33:34|