A-team, thanks, what an amazing animation of the Beaufort, and that floe breaking up.
Incidentally, isn't that the floe that you have been tracking (and measured) since the start of May ?
http://forum.arctic-sea-ice.net/index.php/topic,1493.msg78429.html#msg78429At that time (end of May), I commented that it would bottom-melt once it reached the Beaufort open water and then break up. And I suggested that we should take another look in a week.
Well, that is now 3 weeks ago
This is (was) quite certainly a MYI floe, and it is quite amazing how long it lasted.
But now that it broke I don't see anything magical about the exact fracture lines. Collisions causes odd shear forces, and either way, even toilet paper does not rip along the perforated lines

It is unlikely that Coriolis forces had anything to do with the breakup. Just sustained bottom-melt and a bump from a neighboring floe.
But Coriolis forces almost certainly DO play a role in your animation :
If a floe drifts in a current, Coriolis forces will push it to the right. The ice that drifts in that Beaufort Gyre will thus want to compact, and that is why the whole pack is staying together and not flying all over the place.

Only at the boundary of the Beaufort Gyre, the Alaskan Coastal Current goes the other way.
That's when you get these weird Eddies that spin the ice floes out of the Gyre, and counterclockwise back to the CAA. And yes, some catapult effects are also apparent.
What most astounds me is how much ice the CAB is pushing into the Beaufort, while that sea still manages to melt out so much that its overall area and extent do not go up (while the section of the CAB where all this ice comes from is being torn to shreds).