All AWS AZs are physically separated facilities with redundancy on all their infrastructure, although they're obviously in the same general area.

us-east-1 is not geo-redundant. It is entirely on the east-coast, as the name suggests. Although S3 does have geo-redundancy in all regions.

You may have been thinking of "US Standard", but it is the same as "us-east-1".

http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_r...