Sanity and Deep Ocean Currents Overview
SALINITY AND DEEP OCEAN CURRENTS
OVERVIEW
Ocean currents arise in many different ways. For example, wind pushes the water along the surface to form wind-driven currents. Deep ocean currents are caused by differences in water temperature and salinity. In this experiment, the students will hypothesize the cause of ocean currents and then develop a model to explain the role of salinity and density in deep ocean currents.
CONCEPTS
Salt water is more dense than fresh water, and is therefore heavier.
When ocean water evaporates, the water becomes more dense because most of the salt remains in the water. In some regions of the ocean, circulation is based upon the mixing between more dense surface water and less dense layers of deeper water.
MATERIALS
4 Baby food jars
2 Laminated index cards
Table salt
2 Colors of food coloring
Stir stick
Dish pan (for spills)
Towels
Map of deep ocean currents
Map of sea surface temperature
Map of surface salinities
PREPARATION
It is important to do this activity before your students do it. This will give you a chance to see and work out any potential problems beforehand. Be sure that your jars have flat lips, and have the students add a lot of salt to the salt water jar. Gather the supplies or send a supply list home with the students. Make sure that the students mark their names on anything they bring to class that will be returned home. Set up one activity station for each group of four students. Provide each group with a check list of supplies and a copy of the setup procedures. Make sure that the students complete this activity over a tray or dish pan; it can be very messy. Divide the class into groups of four. This allows for participation of all members. You may wish to assign each student in the group a job. One student could be the equipment and setup monitor. Another student could be the recorder. The third student could be the group spokesperson. The fourth student could be responsible for the
OVERVIEW
Ocean currents arise in many different ways. For example, wind pushes the water along the surface to form wind-driven currents. Deep ocean currents are caused by differences in water temperature and salinity. In this experiment, the students will hypothesize the cause of ocean currents and then develop a model to explain the role of salinity and density in deep ocean currents.
CONCEPTS
Salt water is more dense than fresh water, and is therefore heavier.
When ocean water evaporates, the water becomes more dense because most of the salt remains in the water. In some regions of the ocean, circulation is based upon the mixing between more dense surface water and less dense layers of deeper water.
MATERIALS
4 Baby food jars
2 Laminated index cards
Table salt
2 Colors of food coloring
Stir stick
Dish pan (for spills)
Towels
Map of deep ocean currents
Map of sea surface temperature
Map of surface salinities
PREPARATION
It is important to do this activity before your students do it. This will give you a chance to see and work out any potential problems beforehand. Be sure that your jars have flat lips, and have the students add a lot of salt to the salt water jar. Gather the supplies or send a supply list home with the students. Make sure that the students mark their names on anything they bring to class that will be returned home. Set up one activity station for each group of four students. Provide each group with a check list of supplies and a copy of the setup procedures. Make sure that the students complete this activity over a tray or dish pan; it can be very messy. Divide the class into groups of four. This allows for participation of all members. You may wish to assign each student in the group a job. One student could be the equipment and setup monitor. Another student could be the recorder. The third student could be the group spokesperson. The fourth student could be responsible for the