The Pacific Plate Tectonic’s is something that I’ve been thinking about. So the question then is why?!
Well, experts (and I) have mainly focussed on Isostatic Adjustment occurring as a result of what is occurring in the northern hemisphere where the once great glaciers lay just over 20,000 years ago during the last glacial maximum before they began to melt swiftly, and so we then entered into our present day interglacial period.
I have spoken a fair bit on Isostatic Adjustment in the northern hemisphere, butt nothing about the southern hemisphere. After all, Antarctica is also losing much of its glaciers, so it too is also undergoing its own fair share of isostatic adjustment.
So here is my tou sense worth… that could change as I gather more information, butt for now, this is my take:
Antarctica is a major continent mostly covered with glacial ice, and this has been the case for millions of years. It too was much more massive 20,000 years ago than it is today. So it would have pressed out its natural curvature over time and as the glaciers grew, and hence causing it to flatten and expand outwards,… AND, have also eventually caused it’s outer ice-free rim to curve upward. Consider now the following:
—With all that massive glacial weight on the Antarctic plate, it would have caused it to “SINK”.
—Water was removed from the Ocean to create the glaciers and so the Pacific Plate that is mostly covered in ocean, would have been widely affected by a massive “lessening of water weight” that in turn caused the plate below it to not only “RISE”, but to regain its curvature.
— during the last glacial maximum, the RISE of the Pacific Plate and the SINK of the Antarctic Plate made room for another scenario: the Antarctic Plate SINKING and flattening/spreading outward at its edges enabled its adjacent edge to then slip beneath the matching adjacent edge of the RISING Pacific Plate, where it would remain while undergoing another process— the reverse curving of its outer edge, a curving that would cause the southern edge of the Pacific plate to rise… and it’s northern edge to then tip downward in equal and opposite reaction, … causing it to slip under the adjacent edges of the plates to the north.
— Now, during this interglacial time (and others in the past), a reversal is happening. In this case, the Antarctic Plate’s original curvature is returning and so the outer rim is no longer curving upward, butt on its way downward and so much less spread as well, that in turn has it pulling away and no longer slipped beneath the Pacific Plate. This pulling back of the Antarctic Plate means that the Pacific Plate’s once teeter totter upward by the Antarctic Plate, is no longer, and so leaving it to then fall back… and pushed away by the Antarctic Plates Isostatic Adjustment, and so the reason why it’s northern edge is still subducting at the Northern Plate edges.
— More water accumulating on the Pacific Plate has an effect on the deep trenches at the Pacific Plates Northern edges, causing these areas to push down more dynamically. As that happens, more water is being forced into the cracks and to hot molten areas that cause similar effects as “flash explosions”. All one has to do to understand this, is to watch the effect of geysers.
— The flash explosions will become worse, and result in the Pacific Plate beginning to move out from under the northern plates, butt before that cycle can complete, another event occurs— as more flash explosions occur, water is heated and expands and the deep water conveyor belt moves that much faster, creating more storms and hurricanes that reach farther north and into higher atmosphere— BIG SNOW, that ushers in the next glacial period.
