ISTITUTO NAZIONALE DI GEOFISICA E VULCANOLOGIA

Earthquake with magnitude of Mwp 6.0 on date 21-04-2018 and time 21:44:21 (Italy) in region Western Indian Antarctic Ridge [Sea]

A magnitude Mwp 6.0 earthquake occured in region: Western Indian Antarctic Ridge [Sea], on

  • 21-04-2018 19:44:21 (UTC)
  • 21-04-2018 21:44:21 (UTC +02:00) Italian time
  • 22-04-2018 05:44:21 (UTC +10:00) local time in the region of the earthquake (Australia/Currie)

and geographic coordinates (lat, lon) -48.84, 123.42 at 17 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
Felt maps
The earthquake effects in MCS scale as obtained from the compiled questionnaire

The earthquake effects in MCS scale as obtained from the compiled 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
Rev 100 mb 5.2
Mwp 6.0

Mwpd 6.1
2018-04-21
19:44:21
-48.84 123.42 17 2018-04-21
20:02:50
Sala Sismica INGV-Roma 55928761
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2018-04-21 19:44:21
Latitude -48.84
Longitude 123.42
Depth (km) 17 (from location)
Evaluation mode of Origin automatic
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV-A
Event type earthquake
Origin ID 55928761

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 14279
Semi-minor axis of confidence ellipse (meter) 1955
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 251
Circular confidence region, given by single value of horizontal uncertainty (meter) 11602.4
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 85.3943
Number of associated phases, regardless of their use for origin computation 35
Number of defining phases 35
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 1.12973
Epicentral distance of station closest to the epicenter (degree) 16.56867
Epicentral distance of station farthest from the epicenter (degree) 89.57885
Number of stations at which the event was observed 32
Number of stations from which data was used for origin computation 32
Magnitudes information

Mwpd:6.1

Field Value
Value 6.1
Uncertainty 0.3
Num. used stations 7
Type of magnitude Mwpd
Reference to an origin 55928761
Agency INGV
Autore Auto added
Time of creation (UTC) 2018-04-21 20:02:50

Mwp:6

Field Value
Value 6
Uncertainty 0.1
Num. used stations 12
Type of magnitude Mwp
Reference to an origin 55928761
Agency INGV
Autore Auto added
Time of creation (UTC) 2018-04-21 20:02:50

mb:5.2

Field Value
Value 5.2
Uncertainty 0.1
Num. used stations 24
Type of magnitude mb
Reference to an origin 55928761
Agency INGV
Autore Auto added
Time of creation (UTC) 2018-04-21 20:02:50
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
GT.PLCA.BHZ.00 2018-04-21T19:57:16.58 10.0 positive automatic P 169 89.5789 0.533578 0.0886473
JP.JSD.BHZ. 2018-04-21T19:57:06.60 10.0 positive automatic P 12 87.8664 -1.217 0
IU.MAJO.BHZ.00 2018-04-21T19:56:58.52 10.0 negative automatic P 12 86.3865 -2.16474 0.110065
JP.JGF.BHZ. 2018-04-21T19:56:53.55 10.0 negative automatic P 11 85.3451 -2.00508 0.122895
G.INU.BHZ.00 2018-04-21T19:56:52.16 10.0 positive automatic P 11 85.0527 -1.85299 0.122359
GE.WIN.BHZ. 2018-04-21T19:56:46.65 10.0 positive automatic P 243 83.2155 1.70812 0.142954
IO.EVN.BHZ. 2018-04-21T19:56:45.25 10.0 negative automatic P 328 83.4675 -1.55682 0.0152955
JP.JMN.BHZ. 2018-04-21T19:56:42.95 10.0 positive automatic P 9 83.0917 -1.15067 0
JP.JNU.BHZ. 2018-04-21T19:56:37.25 10.0 negative automatic P 6 82.2301 -2.36265 0.147848
IN.SHL.HHZ. 2018-04-21T19:56:23.93 10.0 positive automatic P 331 79.5697 -1.39204 0.169443
GT.LBTB.BHZ.00 2018-04-21T19:56:08.00 10.0 negative automatic pP 248 76.2775 0.784468 0.209066
GT.BOSA.BHZ.00 2018-04-21T19:55:53.53 10.0 positive automatic pP 245 73.8264 0.429603 0.231929
AF.POGA.BHZ. 2018-04-21T19:55:35.60 10.0 positive automatic pP 250 70.8278 0.573103 0.264859
II.ABPO.BHZ.00 2018-04-21T19:55:11.77 10.0 positive automatic pP 267 66.8028 1.59658 0.292115
TM.UBPT.BHZ. 2018-04-21T19:55:04.60 10.0 positive automatic P 341 66.066 -0.615573 0.324662
MY.KUM.BHZ. 2018-04-21T19:54:07.52 10.0 negative automatic P 333 57.6619 -1.13465 0.435303
MY.LDM.BHZ. 2018-04-21T19:53:45.07 10.0 negative automatic P 354 54.1854 1.29933 0.436575
II.MSVF.BHZ.00 2018-04-21T19:53:40.92 10.0 positive automatic P 75 53.6774 0.751193 0.495188
AU.COEN.BHZ. 2018-04-21T19:51:40.40 10.0 positive automatic P 32 38.4857 -0.0708721 0
AU.KDU.BHZ. 2018-04-21T19:51:26.55 10.0 negative automatic P 15 36.9202 -0.64117 0.798565
IU.SBA.BHZ.00 2018-04-21T19:50:54.77 10.0 positive automatic P 165 33.199 -0.340874 0.844213
GT.VNDA.BHZ.00 2018-04-21T19:50:45.18 10.0 positive automatic P 165 32.1649 -0.901476 0.906242
IU.MBWA.BHZ.00 2018-04-21T19:50:07.67 10.0 positive automatic P 353 27.8353 -0.0946016 0.97561
AU.QLP.BHZ. 2018-04-21T19:50:05.12 10.0 positive automatic P 44 27.4889 0.453307 0.898876
AU.WRKA.BHZ. 2018-04-21T19:49:33.70 10.0 positive automatic P 11 24.105 -0.393648 0.930233
G.CAN.BHZ.00 2018-04-21T19:49:24.55 10.0 positive automatic P 64 23.1219 -0.0480812 0.869565
AU.MORW.BHZ. 2018-04-21T19:48:58.52 10.0 positive automatic P 341 20.5623 1.37385 0.952381
AU.TOO.BHZ. 2018-04-21T19:48:47.30 10.0 negative automatic P 63 19.5234 1.40542 0.952381
AU.HTT.BHZ. 2018-04-21T19:48:43.12 10.0 positive automatic P 43 19.2515 0.190758 0.97561
AU.FORT.BHZ. 2018-04-21T19:48:31.57 10.0 positive automatic P 13 18.3985 -1.89804 0.879121
II.TAU.BHZ.00 2018-04-21T19:48:23.77 10.0 positive automatic P 79 17.5756 0.354407 0.784314
IU.NWAO.BHZ.00 2018-04-21T19:48:11.52 10.0 positive automatic P 342 16.5687 0.672261 0.833333
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download