The University of Southampton Supercomputing facility is called Iridis. The facility is open to research students and members of academic staff from any Faculty, who has the need for compute resources substantially greater than a standard PC. In addition, Iridis hosts the Lyceum service that offers access for undergraduate and MSc project work.
Further Information for local users is available on Internal CMG Iridis pages. As well as documentation on how to access and use the service, it has information on training courses, background information on the facility, user forums and links to sources of further information.
You can get a flavour of kind of research topics enabled by Iridis from this list of scientific projects.