Earthquake with magnitude of ML 1.5 on date 20-11-2021 and time 07:50:15 (Italy) in region Costa Siracusana (Siracusa)

A magnitude ML 1.5 earthquake occured in region: Costa Siracusana (Siracusa), on

  • 20-11-2021 06:50:15 (UTC)
  • 20-11-2021 07:50:15 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 37.184, 15.582 at 10 km depth.

The earthquake was located by: Sala Sismica INGV-Roma.

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.

Municipalities within 20 km from the epicenter

No Italian municipalities within 20 km distance.

Municipalities with at least 50000 inhabitants

An earthquake occurred to
29 Km NE of Siracusa (122291 inhabitants)
56 Km SE of Catania (314555 inhabitants)
60 Km SE of Acireale (52622 inhabitants)
81 Km E of Ragusa (73313 inhabitants)
81 Km E of Modica (54633 inhabitants)
96 Km E of Vittoria (63339 inhabitants)
Recent and historical seismicity
Seismic hazard
Felt maps
Preliminary map of the earthquake effects from the web questionnaire

Preliminary map of the earthquake effects from the web questionnaire

This map shows the distribution of earthquake resentment in the area, expressed in terms of intensity on the MCS scale (Mercalli-Cancani-Sieberg). Intensities are determined using data from questionnaires collected on the website The intensities shown are determined considering all the reports received from each municipality, and are all the more reliable the greater the number of questionnaires. The collected data are subjected to an automatic statistical filter, but are not checked individually. In particular, intensities greater than or equal to the VI degree of the MCS or EMS scale require on-site verification by specialized personnel. The black star is the epicenter of the earthquake that occurred. This map is updated every time citizens fill out new questionnaires. The number of questionnaires processed to obtain this map, the date and time of the last update are shown at the top right.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
ML 1.5 2021-11-20
37.1842 15.582 10 2021-11-20
Sala Sismica INGV-Roma 97618921
Preferred location and magnitude until now.
Origin information


Field Value
Time (UTC) 2021-11-20 06:50:15 ± 0.23
Latitude 37.1842 ± 0.0099
Longitude 15.5820 ± 0.0124
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 97618921


Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 1240
Semi-minor axis of confidence ellipse (meter) 1050
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 45
Circular confidence region, given by single value of horizontal uncertainty (meter) 1240
Confidence level of the uncertainty (%) 68


Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 325
Number of associated phases, regardless of their use for origin computation 8
Number of defining phases 8
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.13
Epicentral distance of station closest to the epicenter (degree) 0.30127
Epicentral distance of station farthest from the epicenter (degree) 0.58816
Number of stations at which the event was observed 4
Number of stations from which data was used for origin computation 4
Magnitude information


Field Value
Value 1.5
Uncertainty 0.1
Num. used stations 2
Type of magnitude ML
Reference to an origin 97618921
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-11-20 06:57:23
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.HLNI.HHZ. 2021-11-20T06:50:35.40 0.3 undecidable manual S 286 0.5882 50 -0.14 69
IV.SSY.HHZ. 2021-11-20T06:50:30.11 0.6 undecidable manual S 266 0.4056 50 -0.03 49
IV.HAGA.HHZ. 2021-11-20T06:50:28.88 0.6 undecidable manual S 287 0.3543 50 0.26 47
IV.HSRS.HHZ. 2021-11-20T06:50:27.02 0.6 undecidable manual S 252 0.3013 50 -0.02 50
IV.HLNI.HHZ. 2021-11-20T06:50:26.85 0.3 negative manual P 286 0.5882 50 -0.19 69
IV.SSY.HHZ. 2021-11-20T06:50:23.91 0.6 negative manual P 266 0.4056 50 -0.01 49
IV.HAGA.HHZ. 2021-11-20T06:50:23.24 0.6 undecidable manual P 287 0.3543 50 0.2 48
IV.HSRS.HHZ. 2021-11-20T06:50:22.16 0.1 positive manual P 252 0.3013 50 0.03 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.HLNI.HHE. ML:1.6 6.55E-5 1.18 AML other m 2021-11-20T06:50:35.08
IV.HLNI.HHN. ML:1.4 4.345E-5 1 AML other m 2021-11-20T06:50:35.26
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download