Strong and shallow M6.2 earthquake hits Samoa Islands region
A strong and shallow earthquake registered by the USGS as M6.2 hit the Samoa Islands region at 15:27 UTC on March 22, 2026. The earthquake occurred at a depth of 10 km (6.2 miles). EMSC is reporting the same magnitude and depth.
Epicenter of M6.2 earthquake in Samoa Islands region, Samoa on March 22, 2026. Credit: TW/SAM, Google
The epicenter was located 150 km (93 miles) SSW of Lotofagā (population 1 126), 157 km (98 miles) SSW of Mulifanua (population 4 508), and 169 km (105 miles) SSW of Apia (population 40 407), Samoa.
Approximately 192 000 people are estimated to have felt light shaking, and 60 000 weak shaking.
There is no tsunami threat from this earthquake, the Pacific Tsunami Warning Center (PTWC) said.
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 vulnerable to earthquake shaking, though resistant structures exist.
The predominant vulnerable building types are informal (metal, timber, GI etc.) and unknown or miscellaneous construction.
This is the second M6+ earthquake of the day, following another M6.2 in the same region.
The Samoa Islands region lies near the northern end of the Kermadec-Tonga subduction system, one of the most seismically active plate boundary zones in the world. This broad tectonic boundary marks the interaction between the Pacific Plate and the Australia Plate, with very rapid convergence and associated deformation generating frequent strong earthquakes across the region.
North of New Zealand, the Australia-Pacific plate boundary extends east of Tonga and Fiji to about 250 km (155 miles) south of Samoa. Along this roughly 2 200 km (1 367 miles) long segment, old Pacific oceanic lithosphere is subducted westward beneath the overriding Australia Plate along the Tonga trench.
Near its northern end, the trench bends sharply westward and transitions from trench-normal subduction to oblique convergence and transform-like motion, producing a complex tectonic setting south of Samoa.
Plate convergence rates increase northward along the system, from about 60 mm (2.4 inches) per year at the southern Kermadec trench to about 90 mm (3.5 inches) per year at the northern Tonga trench.
Because this region also experiences strong back-arc extension in the Lau Basin, the overall rate at which Pacific lithosphere is consumed is even higher, reaching about 150 to 240 mm (5.9 to 9.4 inches) per year along the Tonga trench. These very high deformation rates help explain the frequent occurrence of strong and sometimes very large earthquakes in the broader Tonga-Samoa region.
The Kermadec-Tonga subduction zone produces earthquakes on the plate interface, within both the subducting and overriding plates, and less commonly in the outer rise east of the trench.
Since 1900, 40 earthquakes of M7.5 or greater have been recorded in this system, most of them north of 30°S. One of the most significant events in the Samoa area was the M8.1 outer-rise earthquake of September 29, 2009, which occurred south of Samoa, about 40 km (25 miles) east of the Tonga trench, and generated a tsunami that killed at least 180 people.
Estimated population exposure to earthquake shaking
Selected cities exposed
Regional seismicity
References:
1 M6.2 earthquake Samoa Islands region – USGS – March 22, 2026
2 M6.2 earthquake Samoa Islands region – EMSC – March 22, 2026
3 M6.2 earthquake Samoa Islands region – PTWC – March 22, 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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