how do icebergs start? will they run out?

Where do icebergs begin? As parts of polar caps? Seems like there are some glaciers elsewhere in the world. Are they all freshwater, saltwater, some of each? Are they all just breaking off and heading into the water, or do the glaciers, polar caps grow, etc.

I’m concerned. I want one, too…

Moderator’s Note: I think there are actual answers to these questions (so long as no one brings up Global Warming), so I’ll move this over to General Questions, our forum for matters of fact.

Global warming.

(ducking & running)

How icebergs are formed

Basically, icebergs are fresh water. The ones that are formed by glaciers are close to 100% fresh. Icebergs can form by the freezing of sea water, but even these tend to reject their salt and become fresh over time.

There certainly are non-polar glaciers that form icebergs. Examples are found in Glacier Bay, Alaska. There is a small glacier (Mendenhall, IIRC) a short drive from Juneau that produces small icebergs.

Yes, the polar icecaps are constantly expanding, collecting precipitation, flattening into ice, and moving outwards - the bits that break off around the periphery become icebergs. No, the supply of icebergs won’t run out unless the precipitation stops - and that will mean more problems than just a dearth in the iceberg supply!:eek:

And yes, theoretically, icebergs can be formed by any glacier anywhere in the world - except that, by definition, an “iceberg” is ice that fell off the glacier into the water. Most glaciers occur in steeply-pitched mountain ranges, and the runoff/meltwater doesn’t hang around, so the “icebergs” at the terminus are just hunks of ice that lay around on the ground and melt quietly away. Since they don’t drift, hide their bulk underwater, or sink passenger liners, they don’t get much attention, iceberg-wise.

In the waters off Newfoundland (where Titanic met its demise), the annual spring run of icebergs and “bergy bits” is currently underway. It’s been going on pretty much the same way ever since the last Ice Age ended, with no sign of diminishment, so rest easy on that concern.