Following last week’s major earthquake and its cluster of aftershocks in the Solomon Islands, the seven days from 13-19 February saw earthquake levels subside to levels closer to what we normally expect. Overall, the week saw a total of 121 tremors of at least M4.0 (≥M4.0) of which 36 were ≥M5.0 (10 of them aftershocks from the Solomon islands ‘quake) and just three ≥M6.0.
Again in contrast to last week’s focus on the Solomon islands, there was scarecely a seismically-active region which was unaffected: as well a the usual subduction zone earthquakes among the jumble of microplates that mark the boundary between the Pacific and Australian plates, there were mid-ocean ridge tremors in the Atlantic and Indian oceans.
The Week’s Largest Earthquake: M6.6, Druzhina, Russia
The largest earthquake of the week can also make a case for being one of the most remote. Occurring in the far northeast region of Siberia, the M6.6 which struck at a depth of 10km some 130 km from the village of Druzhina, appears to have had little or no impact.
The remoteness of the location means that there’s very limited available information on the tectonic setting, and although the tremor is likely to have been associated with a marked plate boundary whose nature is unclear: the USGS notes that “Some researchers believe that the Kamchatka seismic belt is the Western boundary of the North American plate …some believe it to be the extension of the Middle Arctic Ocean rift”. Whatever its origin, the area is clearly seismically active, although the week’s M6.6 appears to rank as one of the largest to have been recorded.
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