“Antarctic sea ice reaches lowest levels ever recorded”

(embarrasing moment: this article made me suddenly realise I wasn’t quite sure of the difference between Antarctic and Antarctica)

There’s an article in today’s Guardian about the recent and current retreat of the sea ice at the bottom of the world. It’s a very Guardianesque article about climate change: ominous, anxiety-inducing in some of the readership, but also with enough facts (which can be verified) and quotes from legitimate scientists to make for useful reading.

The article also mentiones the Thwaites glacier, which in media circles is somewhat the enfant terrible of glaciers. One of the reasons I’m exploring the world of MOOCs and other short online courses is to get answers to these questions:

1. How do scientists measure sea ice expansion and retreat?
2. If a glacier of volume X breaks off from an ice sheet, or calves from a glacier, how long does it take to melt?
3. If X is very large (for instance, the aforementioned Thwaites coming off in one go), will its melting affect sea temperatures to any measureable (fraction of a) degree?

There’s other, more obscure, questions, but those are the three which keep coming to mind on reading articles like this. A preliminary search of academic papers doesn’t give clear or easy-to-understand answers, but maybe the right course(s) will?