Strong M6.4 earthquake hits South Sandwich Islands region
A strong earthquake registered by the USGS as M6.4 struck the South Sandwich Islands region at 10:26 UTC on July 11, 2026. The agency is reporting a depth of 46 km (28.6 miles). EMSC is reporting the same magnitude and depth.

Epicenter of M6.4 earthquake in South Sandwich Islands region on July 11, 2026. Credit: TW/SAM, Google
The epicenter was located 2 390 km (1 485 miles) SW of Edinburgh of the Seven Seas (population 271), Tristan da Cunha, Saint Helena, and 2 448 km (1 521 miles) ENE of Ushuaia (population 56 825), Argentina.
There is no tsunami threat from this earthquake.
The USGS issued a Green alert for shaking-related fatalities and economic losses. There is a low likelihood of casualties and damage.
Overall, the population in this region resides in structures that are a mix of vulnerable and earthquake-resistant construction. The predominant vulnerable building types are adobe block with concrete bond beam and unreinforced brick with concrete floor construction.


Estimated population exposure to earthquake shaking


Regional seismicity

References:
1 M6.4 earthquake South Sandwich Islands region – USGS – July 11, 2026
2 M6.4 earthquake South Sandwich Islands region – EMSC – July 11, 2026
I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.

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