The term 'briny expanses' refers to large bodies of saltwater, such as OCEANS and seas. OCEANS are the largest bodies of water on Earth, covering more than 70% of the planet's surface. Seas are smaller bodies of saltwater that are partially enclosed by land. They are usually connected to an ocean, but can also be completely isolated. Both OCEANS and seas contain high concentrations of salt, making them briny expanses.