What is the allusion in the passage? Steger Expedition Amelia Earhart Ernst Shackleton

Since you provided no passage, an Allusion is a figure of speech that make a reference to a place, a person, a novel character or something that happen.

For example here's an Allusion To Shakespeare's Romeo and Juliet:

"Don't be such a Romeo to me Jim, I do not want to be involved in any relationship right now."