Two strong earthquakes struck off the South Sandwich Islands on Saturday, reaching 5.2 and 5.1 magnitude in strength, according to the United States Geological Survey (USGS).

The 5.1 magnitude earthquake struck at a depth of 29 kilometers or about 18 miles, while the 5.2 magnitude earthquake struck at a shallower depth of 10 kilometers, just over 6 miles.

The region is made up of 22 volcanic islands that sit in the southern Atlantic Ocean near Antarctica and are a British Overseas Territory.

Newsweek reached out to the USGS by email during non-working hours Saturday for more information.

Why It Matters

Recent earthquakes near the South Sandwich Islands have highlighted the significant seismic risks present along some of the world's most active fault lines.

This region lies at the intersection of major tectonic boundaries that are known for generating powerful earthquakes and volcanic activity.

What To Know

Saturday's earthquakes struck the region that is part of the South Sandwich Trench, an active subduction zone where the South American Plate converges with the small South Sandwich Plate, causing one plate to plunge beneath the other. This tectonic process is responsible for frequent seismic events in the area.

There were no immediate reports of damage or injuries as the area is not populated by humans.

According to the USGS, the area regularly experiences earthquakes measuring magnitudes 6.0 and above.

Similar tectonic settings along the Aleutian and Kamchatka subduction zones have produced both major earthquakes and volcanic eruptions in recent months.

A 5.1-magnitude earthquake struck Alaska's Aleutian Chain on August 26, and an 8.8-magnitude quake shook Russia's Kamchatka Peninsula on July 29, prompting a Klyuchevskoy volcano eruption and a Pacific-wide tsunami warning.

Over the past month, heightened seismic activity has been documented along several key fault zones spanning the Southern Hemisphere. On August 21, the USGS reported a 7.5-magnitude earthquake in Drake Passage, situated between South America and Antarctica. This event was followed by a 5.1-magnitude aftershock approximately an hour later.

The United States Geological Survey reported two strong earthquakes near the South Sandwich Islands on September 20. USGS

What People Are Saying

Dr. Judith Hubbard, Earth Observatory of Singapore, Nanyang Technological University, Singapore said in a 2021 report about the seismic activity in the region: "The Sandwich Plate is a small piece of young oceanic crust, forming only 300 kilometers to the west at the East Scotia Ridge. On its southern edge, the Sandwich Plate borders the Antarctic Plate across a short transform fault. The plate is marked by a series of regular islands, formed along the volcanic arc of the subduction zone; these volcanic islands (the South Sandwich Islands) give the region its name. They are remote and inhospitable, with no native population, and parts of the islands are permanently covered with ice."

What Happens Next?

Since aftershocks are common following earthquakes, geological monitoring agencies, like the USGS, are expected to continue tracking seismic and volcanic activity in the region for signs of ongoing risk.

Regional authorities and international monitoring stations will issue alerts if tsunami risks develop as a result of these earthquakes.