The Thaumanova Reactor was built atop of a ley line and what we saw was a chaotic surge of magical energies like we are seeing now – we’re basically seeing similar reactions going on, though from different causes (Thaumanova = chaos and dragon magic mixing atop of ley line; Ley Lines = overflow of magic).
If I’m correct, the Ley-Line Anomalies explode if left alone/gather too much magic, so in theory the failure of letting them absorb too much magic could be duplicating the Thaumanova Reactor explosion – though with less chaos magic involved (thus no teleporting, rivers running upward, air full of underwater bubbles, drastically different harsh environments adjacent to while unaffecting each other, etc).
But if it’s controlled in how much magic is absorbed, then – see the link Randulf gave. TL;DR: how djinn come to be is the theory.
Dear ANet writers,
Stop treating GW2 as a single story. Each Season and expansion should be their own story.
