The ocean is huge and full of wonders, so it's no surprise our listeners have lots of question about it. In this episode we'll travel to the bottom of the ocean to find out what the ocean floor is made of, and learn how geologist Marie Tharp helped us understand how amazing it is. We'll also delve into why the ocean is salty but lakes and rivers aren't, and sing along with the Salty Sea Shanty. Plus a brand new mystery sound!This episode was sponsored by:Indeed (indeed.com/BRAINSON - to receive a $75 sponsored job credit to upgrade your job posting)Shopify (Shopify.com/brainson - for a free 14-day trial and full access to Shopify's entire suite of features) BrainsOnSaltySeaShanty Our Salty Sea Shanty complete with sea creature drawings sent in by our listeners! See omnystudio.com/listener for privacy information.