Answer:
Both deltas and alluvial fans are types of depositary land forms created by rushing rivers.
Explanation:
Both deltas and alluvial fans are types of depositary land forms created by rushing rivers. Alluvial fans are created at the foothills, where streams running from a higher elevation break into low gradient foothills, while deltas are formed at the mouth of streams, where they enter seas or saline water bodies.
It isn't exactly known who discovered it first, but the earliest claim of earth being round rather than flat was posed by Pythagoras sometime around 500 B.C. He argued that if the moon was round the Earth should be as well.
After that, his claim was proven true by a man named Anaxagoras at around 500-430 B.C when he brought up solar and lunar eclipses. The shape of Earth's shadow on the moon was also used as evidence that the Earth was round.
And finally, in 350 B.C the great Aristotle declared that the Earth was a sphere based on constellations you can see if you travel farther from the equator. Over the next hundred or so years, Aristarchus and Eratosthenes actually measured the size of the earth.
Short answer: The Greeks