I understand. I took three college level geology courses and I find this stuff fascinating.
See the “V” it heads into just before it slides under between the Russian Peninsula and the Aleutian plates? I think that might be an indicator that the chain is caught in the middle between two different plate pushes both northeast and northwest as they move towards that V.
I find it fascinating too... Had two very successful great uncles who were geologists extraordinaire. I was fortunate to have had apprentice time with them before they passed and learned quite a bit.