aws s3 mb s3://<bucket-name>
# or
aws s3api create-bucket --bucket <bucket-name> --region <region>
# if error occurs as: (BucketAlreadyExists)
# need to specify unique name like "bucket-name-5184653123"
$ aws s3api create-bucket --bucket my-second-emr-bucket --region us-east-2 --create-bucket-configuration LocationConstraint=us-east-2