Actually there are not 7 regions for Google Cloud Storage but 3: US, EU, ASIA. You can get more specfic but that's still Alpha: ASIA-EAST1, US-CENTRAL1, US-CENTRAL2, US-EAST1, US-EAST2, US-EAST3, US-WEST1.

Note that there are separate zones for Google Compute Engine: https://cloud.google.com/compute/docs/zones#available