If I recall correctly, this was a hoax, I don't think there was a capture off his twitter page that was authentic.

However, this was during a period where several higher ups were getting tours of Antarctica, and so this was highly suspect.

Also, imagine sending your one message to people, saying "fear an unknown danger with no scope of what it could be with a pointy mountain behind t with really weird cloud/snow formation.

I am really into antartica but I'm pretty sure I saw a debunking of why this isn't legit I think it had to do with the original formatting of the picture compared to twitter at the alleged time of tweet.

Also the image OP sent in is basically in shambles quality wise, it's very poor quality, should also speak to some truth there.