So it pretty much goes like:

1. Inbalance in favor of one element in one of the shards. (water for e.g.)
2. Aether starts tickling to the source. (causing smaller to medium disturbances in the source as well as in the shard)
3. Something "cracks" the barrier between (the war of magi for e.g.)
4. All the aether plus the shard itself flowes back to the source at once (rejoining), which...
5. ...causes a calamity.

Did I get it right?