Sand and silt are both examples of granular materials, which are collections of separate particles and distinct particles, such as raw flour in a container or jellybeans in a jar.The most common forms of sand and silt are composed of tiny fragments of quartz.
Rip tides, also known as rip currents, are strong narrow currents that can pull swimmers out to sea. Some rip tides are so strong that they can drag swimmers away from shore before they realise what is happening. Swimmers should keep an eye out for rip tides while swimming in the sea at the beach. Rip tides can be identified by discoloured water, choppy waves and a foamy surface. They can be filled with debris. Swimmers are told to remember the âthree Rsâ if they become caught in a rip tide.
Red tides are caused by an explosive growth and accumulation of certain microscopic algae, predominantly dinoflagellates, in coastal waters. Some species of dinoflagellates produce toxins that are among the most potent known to man.lorida red tide is a specific type of Harmful Algae Bloom (HAB). 1  HABs are a worldwide phenomenon. 2  Red tide is caused by a microscopic algae, Karenia brevis.