Of the 42 major quakes recorded this year only two, a mag 6.2 recorded in Mongolia in January and a mag 6.3 recorded in Grecce earlier this month have been outside the Pacific Ring Of Fire. Stranger still 36 of the 42 have been on the Western side of the Pacific Ring leaving the Western Coast of the US still waiting for the "big one!"
To emphasise the incredible total of major quakes so far this year, we have to go back to earlier years for comparison. Last year in the same period during the dark beginning of 2020 a total of 24 major quakes, mag 6 or higher had been recorded around the globe, coincidently not one recorded along the eastern margin of the Australia plate which is dominating this year's activity.
Back in 2019, just 20 major quakes had been reported up to March the 6th, just 50% of this year's total. In 2018, 24 major quakes had been reported and in 2017, just 15, 2017 went on to record the lowest amount of major quakes this century. In 2016, 24 and in 2015, just 18. Coincidentally, the highest number ever recorded in a year was 207 in 2011, the year of the Fukushima disaster, however, in that year up to March the 6th only 30 major quakes, mag 6 or higher had been recorded.
According to USGS, the eastern margin of the Australia plate is one of the most seismically active areas of the world due to high rates of convergence between the Australia and Pacific plates.
In the region of New Zealand, the 3000 km long Australia-Pacific plate boundary extends from south of Macquarie Island to the southern Kermadec Island chain. It includes an oceanic transform (the Macquarie Ridge), two oppositely verging subduction zones (Puysegur and Hikurangi), and a transpressive continental transform, the Alpine Fault through South Island, New Zealand.
What is happening along the eastern margin of the Australia plate this year is similar to the great Honshu quake swarm on the Japanese Trench back in 2011 when around 70 major quakes, mag 6 or higher caused the destruction of the Fukushima Nuclear Plant and resulted in the deaths of 22,000 people. The 2011 total of recorded major quakes was the highest ever at 207.
Back in 1957 another swarm, 74 major quakes struck the Aleutian arc extending approximately 3,000 km from the Gulf of Alaska resulting in the then-record number of quakes in a year of 205.
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