A magnitude 6.9 earthquake struck the Macquarie Island region in the Southern Ocean at 22:10 UTC on July 28, 2025, according to the United States Geological Survey (USGS). The quake was recorded at a depth of either 31 km (19.2 miles) per USGS or 10 km (6.2 miles) per EMSC. No tsunami threat was issued.
The epicenter was located about 1,436 km (892 miles) southwest of Bluff, New Zealand, in a remote and sparsely inhabited area. The USGS reported no felt reports from the public at the time of publication and issued a Green alert, indicating a low likelihood of casualties or economic damage. Most structures in the area are built to resist seismic shaking, although unreinforced and informal buildings remain vulnerable.
The Macquarie Island event occurred amid a noticeable global uptick in seismic activity:
- A 6.5-magnitude earthquake struck Sabang, Indonesia, just hours earlier on July 28 at a depth of 10 km (6.2 miles)
- A 5.3-magnitude earthquake hit Alaska on July 27 at 83 km (52 miles) depth
- Another 6.2-magnitude earthquake occurred in the Macquarie region on July 26, also at 10 km depth
- A series of M6.6 earthquakes rattled Wallis and Futuna on July 24, at depths of 314.2 km (195 miles) and 144.6 km (90 miles)
- Recent seismic activity also included quakes in Russia (M6.3, July 22) and Alaska (M4.8 and M5.0, July 21–22)
These events, while occurring in different tectonic settings, suggest a temporally clustered sequence of moderate-to-strong global quakes, likely driven by natural plate movement cycles.
Aftershocks continue
The Macquarie Island quake was followed by several aftershocks:
- M5.4 at 22:20 UTC
- M5.1 at 22:59 UTC
- Another shallow M5.4 at 00:21 UTC on July 29
These followed two earlier M6.2 earthquakes in the same region on July 25 and 26, both at shallow depths, indicating a prolonged stress release along the Macquarie Ridge—a known seismic zone between the Australian and Pacific plates.
