xkcd #3221: Landscape Features
Title text:
'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3221/
Many rivers begin with glaciers. The Colorado, Mississippi, and Rio Grande, for example, still receive glacier melt to this day