Earthquake with magnitude of Mwpd 8.1 on date 12-08-2021 and time 20:32:53 (Italy) in region South Georgia & the South Sandwich Is. [Sea]

A magnitude Mwpd 8.1 earthquake occured in region: South Georgia & the South Sandwich Is. [Sea], on

  • 12-08-2021 18:32:53 (UTC)
  • 12-08-2021 20:32:53 (UTC +02:00) Italian time
  • 12-08-2021 16:32:53 (UTC -02:00) local time in the region of the earthquake (Atlantic/South_Georgia)

and geographic coordinates (lat, lon) -57.157, -24.596 at 20 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

No Italian municipalities within 100 km from the epicenter with at least 50000 inhabitants.

Recent and historical seismicity
Seismic hazard
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 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.

Intensity Shakemap

Intensity Shakemap

This map shows the distribution of the istrumentally derived intensities. To this purpose, it is used a conversion relation between ground acceleration and velocity, and the Mercalli Modificata (MMI - Modified Mercalli Intensity) scale. In general, the Mercalli intensity scale relies on the effects that the ground shaking produces as reported by an observer.
Peak ground acceleration Shakemap

Peak ground acceleration Shakemap

This map shows This map shows the distribution of peak ground acceleration expressed as per cent 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 the effects of the earthquake on the territory in terms of the MCS (Mercalli-Cancani-Sieberg) intensity scale. The intensities are determined using the data provided in the questionnaire (http://www.haisentitoilterremoto.it/) that are analysed using robust statistical techniques since they are not verified individually. Specifically, the assignment of MCS intensities greater or equal the VI degree of the MCS scale require opportune in situ verification by professional experts. The purple start shows the epicenter. This map is prepared every so often that the population fill in new questionnaires. The number of questionnaires used to determine the map and the date and time of the last adjournment are shown in the upper right part of the panel.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Reviewed
Rev100
mb 5.5
Mwp 7.3
Mwpd 8.1
2021-08-12
18:32:53
-57.157 -24.5964 20 2021-08-12
18:52:45
Sala Sismica INGV-Roma 94021471
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-12 18:32:53
Latitude -57.1570
Longitude -24.5964
Depth (km) 20 (from location)
Evaluation mode of Origin automatic
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV-A
Event type earthquake
Origin ID 94021471

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 24190
Semi-minor axis of confidence ellipse (meter) 15416
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 14
Circular confidence region, given by single value of horizontal uncertainty (meter) 19525.2
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 69.8344
Number of associated phases, regardless of their use for origin computation 60
Number of defining phases 60
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 2.90858
Epicentral distance of station closest to the epicenter (degree) 7.27539
Epicentral distance of station farthest from the epicenter (degree) 98.19047
Number of stations at which the event was observed 59
Number of stations from which data was used for origin computation 59
Magnitudes information

Mwp:7.3

Field Value
Value 7.3
Uncertainty 0.1
Num. used stations 40
Type of magnitude Mwp
Reference to an origin 94021471
Agency INGV
Autore early-est_ee1.1.9
Time of creation (UTC) 2021-08-12 18:52:45

Mwpd:8.1

Field Value
Value 8.1
Uncertainty 0.3
Num. used stations 42
Type of magnitude Mwpd
Reference to an origin 94021471
Agency INGV
Autore early-est_ee1.1.9
Time of creation (UTC) 2021-08-12 18:52:45

mb:5.5

Field Value
Value 5.5
Uncertainty 0.1
Num. used stations 47
Type of magnitude mb
Reference to an origin 94021471
Agency INGV
Autore early-est_ee1.1.9
Time of creation (UTC) 2021-08-12 18:52:45
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
AF.ALKP.BHZ. 2021-08-12T18:40:42.16 10.0 negative automatic P 70 42.1994 -1.20394 0.689074
IU.PAB.BHZ.00 2021-08-12T18:46:29.07 10.0 negative automatic PcP 16 98.1905 1.49555 0
PM.PESTR.BHZ. 2021-08-12T18:46:26.95 10.0 negative automatic P 13 97.0848 4.47186 0.0239414
AU.QLP.BHZ. 2021-08-12T18:46:21.87 10.0 positive automatic P 170 95.7259 5.60195 0.0538763
AU.WRKA.BHZ.00 2021-08-12T18:46:17.23 10.0 negative automatic P 156 94.6898 5.62215 0.0639932
IU.TEIG.BHZ.00 2021-08-12T18:46:09.95 10.0 positive automatic P 303 93.7131 2.92615 0.0325008
AU.ARMA.BHZ. 2021-08-12T18:46:07.07 10.0 negative automatic P 177 92.3624 6.08946 0.0759287
AU.RIV.BHZ. 2021-08-12T18:45:52.40 10.0 positive automatic sP 176 88.9388 -0.0668313 0
AU.MORW.BHZ. 2021-08-12T18:45:43.55 10.0 positive automatic P 146 87.6063 4.95173 0.109899
AU.HTT.BHZ. 2021-08-12T18:45:42.10 10.0 positive automatic P 166 88.3427 -0.069109 0.103336
G.CAN.BHZ.00 2021-08-12T18:45:39.00 10.0 positive automatic P 175 87.3619 1.51395 0.110404
NZ.OUZ.HHZ.10 2021-08-12T18:45:36.16 10.0 positive automatic P 195 86.347 3.74012 0.0416457
CU.MTDJ.BHZ.00 2021-08-12T18:45:35.20 10.0 positive automatic P 311 87.2632 -1.84414 0
AU.TOO.BHZ.00 2021-08-12T18:45:30.65 10.0 positive automatic P 172 84.8988 5.33076 0.129184
AU.MILA.BHZ.00 2021-08-12T18:45:28.80 10.0 positive automatic P 175 85.6367 -0.236825 0.121984
GE.BOAB.BHZ. 2021-08-12T18:45:25.70 10.0 positive automatic P 301 85.6911 -3.53913 0.12591
G.TAM.BHZ.00 2021-08-12T18:45:20.80 10.0 negative automatic P 28 83.8538 0.640458 0.128623
NZ.URZ.HHZ.10 2021-08-12T18:45:19.35 10.0 positive automatic PcP 197 82.8375 -0.140355 0
IU.SNZO.BHZ.00 2021-08-12T18:45:04.82 10.0 positive automatic pP 195 80.2021 -2.39368 0
II.TAU.BHZ.00 2021-08-12T18:45:03.62 10.0 positive automatic P 174 79.6998 5.57549 0.169718
NZ.KHZ.HHZ.10 2021-08-12T18:45:00.73 10.0 positive automatic pP 194 79.2657 -2.84467 0
NZ.ODZ.HHZ.10 2021-08-12T18:44:48.61 10.0 positive automatic pP 191 77.0043 5.44309 0.0703647
GE.KMBO.BHZ.00 2021-08-12T18:44:28.67 10.0 negative automatic P 66 74.1926 1.32402 0.150796
II.MBAR.BHZ.00 2021-08-12T18:44:12.07 10.0 positive automatic P 60 71.4982 0.798561 0.237831
IU.OTAV.BHZ.00 2021-08-12T18:44:08.92 10.0 positive automatic P 302 71.5511 -3.03545 0.183895
GE.SBV.BHZ. 2021-08-12T18:44:08.95 10.0 negative automatic pP 84 70.3431 -1.4478 0
GT.DBIC.BHZ.00 2021-08-12T18:43:36.00 10.0 positive automatic P 22 65.8283 0.314553 0.340317
G.MPG.BHZ.00 2021-08-12T18:43:36.25 10.0 positive automatic P 329 66.2997 -2.46632 0
GE.VOI.BHZ. 2021-08-12T18:43:13.00 10.0 negative automatic pP 87 61.7006 -1.95782 0
II.NNA.BHZ.00 2021-08-12T18:43:00.62 10.0 positive automatic pP 297 60.0425 -2.94294 0
IU.CASY.BHZ.00 2021-08-12T18:42:00.17 10.0 positive automatic P 159 52.0781 -0.0589603 0.260072
GT.LPAZ.BHZ.00 2021-08-12T18:41:59.53 10.0 negative automatic P 303 52.1889 -2.35436 0.530727
IU.TSUM.BHZ.00 2021-08-12T18:41:36.42 10.0 positive automatic P 57 49.0126 -0.866061 0.570027
GT.LBTB.BHZ.00 2021-08-12T18:41:27.30 10.0 negative automatic P 70 47.9381 -1.69198 0.602055
GE.WIN.BHZ. 2021-08-12T18:41:12.50 10.0 negative automatic P 59 45.8558 -0.316801 0
GT.BOSA.BHZ.00 2021-08-12T18:41:07.38 10.0 negative automatic P 72 44.8174 2.87465 0.303361
GT.VNDA.BHZ.00 2021-08-12T18:41:05.38 10.0 negative automatic P 182 45.2639 -2.47764 0.634133
IU.SBA.BHZ.00 2021-08-12T18:41:02.50 10.0 positive automatic P 183 44.8105 -1.73831 0.600241
C.GO03.BHZ. 2021-08-12T18:40:56.78 10.0 positive automatic P 293 43.5106 2.84311 0.314367
IU.LCO.BHZ.00 2021-08-12T18:40:49.67 10.0 positive automatic P 291 42.5803 2.99739 0.651804
BL.PMNB.HHZ. 2021-08-12T18:40:40.45 10.0 positive automatic P 328 41.8891 -0.362931 0.735835
C.GO04.BHZ. 2021-08-12T18:40:36.65 10.0 positive automatic P 290 41.6867 -2.70496 0.652936
C1.CO02.BHZ. 2021-08-12T18:40:30.35 10.0 positive automatic P 289 40.9598 -2.8748 0.728897
II.SUR.BHZ.00 2021-08-12T18:40:25.37 10.0 negative automatic P 71 39.5114 4.0496 0.349267
G.PEL.BHZ.00 2021-08-12T18:40:22.35 10.0 positive automatic P 288 39.2525 3.3694 0.727149
WA.ZON.HHZ. 2021-08-12T18:40:16.96 10.0 negative automatic P 291 39.5065 -4.14866 0.771535
C.GO05.BHZ. 2021-08-12T18:40:13.48 10.0 positive automatic P 284 38.4564 1.27573 0.358779
GT.CPUP.BHZ.00 2021-08-12T18:40:11.43 10.0 positive automatic P 309 38.5976 -1.96582 0.793473
AU.MAW.BHZ. 2021-08-12T18:40:09.15 10.0 positive automatic P 142 38.1925 -0.817274 0.782554
C1.BO02.BHZ. 2021-08-12T18:40:07.57 10.0 negative automatic P 286 38.0225 -1.11287 0.785912
G.SPB.BHZ.00 2021-08-12T18:40:04.00 10.0 positive automatic P 324 37.4066 0.565243 0.657292
C.GO06.BHZ. 2021-08-12T18:39:44.05 10.0 positive automatic P 280 34.8056 2.76778 0.760303
GT.PLCA.BHZ.00 2021-08-12T18:39:26.13 10.0 negative automatic P 279 33.4924 -3.73615 0.88863
C1.LL02.BHZ. 2021-08-12T18:39:23.80 10.0 positive automatic P 275 32.4954 2.77144 0.84851
G.COYC.BHZ.00 2021-08-12T18:39:13.10 10.0 positive automatic P 271 31.0676 4.64829 0.848644
C.GO10.BHZ. 2021-08-12T18:38:30.73 10.0 positive automatic P 259 26.31 -1.35238 0
C1.MG02.BHZ. 2021-08-12T18:38:17.53 10.0 positive automatic P 261 25.5096 -1.2785 0.963855
II.EFI.BHZ.00 2021-08-12T18:37:21.02 10.0 positive automatic P 272 20.0036 -2.06022 0.963855
II.HOPE.BHZ.00 2021-08-12T18:34:39.67 10.0 positive automatic P 288 7.2754 2.79368 0.930233
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download