Sandwich Islands 

Segnale King Edward Point 13.08.21 OK

Sealevel King Edward 13.08.21 

At 18:32 UTC (16:32 local time and 20:32 Italian time) yesterday, August 12, 2021, a magnitude Mwpd 8.1 earthquake was recorded in the South Atlantic Ocean at sea (Lat. -57.157, Lon. -24.596) offshore the South Sandwich Islands at about 20 km depth.

An information message has been issued by the Pacific Tsunami Warning Center (external link) and the JATWC (Australian Tsunami Service Provider)  to the national reference Tsunami Service Providers.

The recorded earthquake is part of a complex seismic sequence. Seismogram analysis indicates a stronger earthquake occurred about three minutes after the M7.5 initial shock followed by an intense and prolonged aftershock sequence.

Such earthquakes require in-depth seismologist analysis and detailed modeling that may take several days.

The King Edward Point mareograph (external link) registered sea level changes of about 80cm.


*Flanders Marine Institute (VLIZ); Intergovernmental Oceanographic Commission (IOC) (2021): Sea level station monitoring facility. Accessed at on 2021-08-13 at VLIZ. DOI: 10.14284/482