Earthquake with magnitude of Mw 4.9 on date 26-12-2018 and time 03:19:14 (Italy) in region 4 km NE Viagrande (CT)

A magnitude Mw 4.9 earthquake occured in region: 4 km NE Viagrande (CT), on

  • 26-12-2018 02:19:14 (UTC)
  • 26-12-2018 03:19:14 (UTC +01:00) Italian time

and geographic coordinates (lat, lon) 37.6440, 15.1160 at -0 km depth.

The earthquake was located by: Gruppo Analisi Dati Sismici, Osservatorio Etneo.

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

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Viagrande CT 4 8563 8563
Aci Sant'Antonio CT 4 17984 26547
Trecastagni CT 4 10910 37457
Aci Bonaccorsi CT 5 3524 40981
Aci Catena CT 5 29851 70832
Santa Venerina CT 5 8592 79424
Pedara CT 6 14102 93526
Acireale CT 6 52622 146148
Zafferana Etnea CT 6 9517 155665
Valverde CT 7 7840 163505
San Giovanni la Punta CT 8 23060 186565
Nicolosi CT 8 7463 194028
Tremestieri Etneo CT 8 20589 214617
San Gregorio di Catania CT 9 11966 226583
Milo CT 9 1087 227670
Mascalucia CT 10 31958 259628
Sant'Agata li Battiati CT 10 9479 269107
Aci Castello CT 10 18723 287830
Gravina di Catania CT 10 25838 313668
San Pietro Clarenza CT 11 7743 321411
Giarre CT 11 27659 349070
Sant'Alfio CT 12 1582 350652
Riposto CT 13 14838 365490
Camporotondo Etneo CT 13 5023 370513
Belpasso CT 14 28108 398621
Mascali CT 15 14282 412903
Ragalna CT 16 3924 416827
Catania CT 16 314555 731382
Misterbianco CT 17 49410 780792
Fiumefreddo di Sicilia CT 19 9623 790415
Piedimonte Etneo CT 19 3963 794378
Motta Sant'Anastasia CT 19 12116 806494

Municipalities with at least 50000 inhabitants

An earthquake occurred to
6 Km NW of Acireale (52622 inhabitants)
16 Km N of Catania (314555 inhabitants)
67 Km N of Siracusa (122291 inhabitants)
70 Km SW of Reggio di Calabria (183035 inhabitants)
72 Km SW of Messina (238439 inhabitants)
87 Km NE of Ragusa (73313 inhabitants)
93 Km NE of Vittoria (63339 inhabitants)
93 Km NE of Modica (54633 inhabitants)
94 Km E of Caltanissetta (63360 inhabitants)
100 Km NE of Gela (75827 inhabitants)
Recent and historical seismicity

These maps show the seismic activity in different time intervals, before the seismic event to which they refer. Data reported in the first two maps come from the analysis carried out in real time by the personnel of the INGV Operating Rooms, immediately after each earthquake. The third map shows data from 1985 to the date of the earthquake: the locations are reviewed by the seismological analysts of the INGV Italian Seismic Bulletin (Bollettino Sismico Italiano dell’INGV). The localization parameters (hypocentral coordinates and magnitude) are the best possible estimate with the data available to the INGV, but are constantly updated according to further data that become available. The location and magnitude parameters, subsequently reviewed by seismological analysts, may vary.

Earthquakes of the 3 days preceding this event

Earthquakes of the 3 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 0.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 72 hours preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes of the 90 days preceding this event

Earthquakes of the 90 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 2.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 90 days preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes from 1985 to the date of the event

Earthquakes from 1985 to the date of the event

This map shows the earthquake epicenters with magnitude ≥ 3.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, from 1985 to the date of this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes since 1000 AD until 2019

Earthquakes since 1000 AD until 2019

This map shows the epicenters of the historical earthquakes catalogue CPT15 (Catalogo Parametrico dei Terremoti Italiani, 2015 version 3.0, https://doi.org/10.13127/cpti/cpti15.3) since 1000 AD until 2019. The size of the square indicates the different classes of magnitude. For earthquakes with magnitude ≥ 6.0, it is also shown the year of occurrence and the magnitude value. The black and white star is the epicenter of the current earthquake.
Seismic hazard

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.

Seismic hazard map

Seismic hazard map

This map shows the seismic hazard map of Italy for the region where the earthquake occurred.
Shakemap

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 updated as more data become available. See http://shakemap.ingv.it for additional information. The black star indicates the epicenter. The triangles show the accelerometric and velocimetric stations used in the calculation, colored according to the recorded shaking.

Intensity Shakemap

Intensity Shakemap

This map shows the distribution of instrumental intensities. The intensity is derived through an empirical law that correlates the recorded values of actual ground shaking, e.g., acceleration and velocity, with the macroseismic intensity for Italian earthquakes, as reported in the Italian Macroseismic Database (DBMI15, https://doi.org/10.13127/cpti/cpti15.3).
Peak ground acceleration Shakemap

Peak ground acceleration Shakemap

This map shows the distribution of peak ground acceleration expressed as percent of the acceleration of gravity (i.e., g = 9.81 m/s²).
Peak velocity Shakemap

Peak velocity Shakemap

This map shows the distribution of peak ground velocities expressed in cm/s.
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 http://www.hsit.it. 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
Reviewed
Rev200
ML 4.8 2018-12-26
02:19:14
37.644 15.116 -0 2019-01-31
13:49:09
Gruppo Analisi Dati Sismici, Osservatorio Etneo 64733411
Reviewed Evaluation Mw
Rev501
Mw 4.9 2018-12-26
02:19:14
37.625 15.102 3 2018-12-26
08:50:05
TDMT-INGV Revised 64237231
Reviewed
Rev200
ML 4.8 2018-12-26
02:19:14
37.625 15.102 1 2018-12-26
02:34:02
Sala Operativa INGV-OE (Catania) 64229911
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2018-12-26 02:19:14
Latitude 37.6440
Longitude 15.1160
Depth (km) 0 ± 0 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 200 -> BULLETIN-OE
Event type earthquake
Origin ID 64733411

Uncertainty

Field Value
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) 100.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 88
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) 0.27
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
Magnitudes information

Mw:4.9

Field Value
Value 4.9
Uncertainty
Num. used stations
Type of magnitude Mw
Reference to an origin 64237231
Agency INGV
Autore TDMT-INGV Revised
Time of creation (UTC) 2018-12-26 08:50:05

ML:4.8

Field Value
Value 4.8
Uncertainty 0.2
Num. used stations
Type of magnitude ML
Reference to an origin 64733411
Agency INGV
Autore Sala Operativa INGV-OE (Catania)
Time of creation (UTC) 2019-01-17 14:39:40

ML:4.8

Field Value
Value 4.8
Uncertainty 0.2
Num. used stations
Type of magnitude ML
Reference to an origin 64229911
Agency INGV
Autore Sala Operativa INGV-OE (Catania)
Time of creation (UTC) 2018-12-26 02:34:02
TDMT - Time Domain Moment Tensor

TDMT details

Field Value
Magnitude4.9
Scalar Moment2.76774E+23 dyne-cm
Computed depth3 km
QualityBa
Variance Reduction32.88%
Double Couple98%
CLVD2%
ISO0%
Model usedCIA
Modemanual
Statusreviewed

Moment Tensor Components

Component Value
Mrr-1.13909E+22
Mtt-2.351043E+23
Mpp2.464951E+23
Mrt9.02496E+22
Mrp-5.40268E+22
Mtp-8.6414E+22

Nodal Planes

Name Strike Dip Rake
PN130688-158
PN221568-3

Fault Plane solution

Focal Mechanism

psmeca (GMT documentation)

15.102 37.625 3 306 88 -158 215 68 -3 2.76774 23 15.602 38.125

TDMT references

More info and references

Station Distribution

Station Distribution

TDMT station details

Sta Dist Azi V R zcor
IST3 130.8 4.9 20.67% 108
TDS 250.2 25.1 50.26% 118
MSRU 79.4 26.6 37.19% 102
CAR1 205.1 27.8 37.25% 114
PIPA 254.8 35.4 50.96% 121
TIP 225.2 39.5 61.02% 118
HAGA 38 172.9 36.98% 97
SSY 51.9 182.8 20.7% 99
CROCE 101.3 210 22.59% 104
MUCR 50.6 336.7 31.28% 100
MTTG 67.3 51.3 34.69% 104
HLNI 36.8 213.6 31.66% 99
CEL 99.1 44.4 51.66% 106
PLAC 148.8 51.6 31.13% 113
CSLB 98.3 291 32.39% 109
Fault Plane solutions in the area
Fault Plane solutions

Fault Plane solutions

The map reports the fault plane solutions for earthquakes in the region from 1977 to the date of this event. Red moment tensors are determined using the Regional Centroid Moment Tensor technique (RCMT, http://www.bo.ingv.it/RCMT) applied for earthquakes with magnitude larger than 4.5 in the Euro-Mediterranenan area. Occasionally, when a station azimuthal coverage exists RCMTs can be obtained also for earthquakes with magnitude down to 4.0. The gray moment tensors are obtained with the Time Domain Moment Tensor method (TDMT, http://terremoti.ingv.it/tdmt). This technique is applied to earthquakes with magnitude ML greater than 3.2, when it is possible. The size of symbols scales with the calculated moment magnitude Mw.
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download
Waveforms Seismic signals in miniseed + resp format Download