Hi,
I don't know if it is my computer screen but the pictures appear abit dark or underexposed? Like benedium pointed out, there have been very dramatic and magnificent pictures posted from these locations (I wish I could shoot like that!) and it seems like the pictures don't fully exercise the potential in those conditions and location.
Having said that, I think these are a good effort, better than what I could probably achieve in fact! keep shoot and keep learning, so am I!