Calving means different things to diverse people. While from early spring thru summer, calving happens every year. If you GOOGLE calving be sure your interests lie in either ranching or geology (glaciers). While both perfectly natural; one is a miracle (?), the other magnificent.
Glacier buoyancy: I’ve never seen it filmed line this; with the complete alomst instant readjustment of buoyancy, usually it occurs more slowly and glacier float into warmer water.