nostr:npub1psdfxfpxz2cwmmnsk60y3nqpn2tqh9n24h4hstvfkwvr6eaek9js499sr7 
Yes.  But I'd still like to know how much faster.  It's not obvious how to work it out, either.
I suppose I should try.
The floating ice is floating; no change.  The change in volume will come from glaciers moving off solid substrate (neglecting  thermal expansion for now, and it's complicated anyway because the chemistry will affect it).  
The volume change is the simple bit.
/cont