Random Questions Play Along

Having turned in grades for the term, and put work behind me for the day, I stood on my porch. I contemplated the new foligage, the crane flying over, a squirrel whose attention I failed to get. At times like this, my brain goes all unfocused. A good feeling. Immediately interrupted by one of several thoughts, but this time one of my random questions. Random Questions are usually really stupid/obvious/irrelevant, but my brain poses them in such a way as to be interesting for a moment. I'll go first with today's RQ: If the water that makes up the oceans flows out of rivers, melts from glaciers, and falls from the sky, none of which have much salt in them (? embedded RQ), how do the oceans maintian consistent levels of salination? Proposed solutions: glaciers have salt in them and no one told me; minerals from the river silt include or combine to create salt; volcanoes and volcanic vents in the deep contribute salt to the oceans. And possibly, D, all of the above. Note that all of the proposed solutions are themselves Embedded Random Questions (ERQs). I can spend way too much in these briar patches. Questions of this kind make my father lovingly kid me about the PhD. Clearly there are gaps in my education. ;-) So, what's your recent or favorite RQ?