In this activity developed by NOAA, students learn about tides and salinity in estuaries. They observe time-lapse models of tides and salinity distribution in the York River, part of the Chesapeake Bay, VA NERR. Learn how salinity changes with an incoming and outgoing tide, observing the dynamics of the salt wedge at various sites along the river. Students also make predictions about the salinity changes at each site based upon their observations of the animation. They then use salinity data from monitoring stations along the river to see changes during a typical day. And, then describe the patterns of each salinity graph and compare the graphs.
Students will be able to:
- Analyze different forms of data and synthesize information to develop a hypothesis.
- Explain how tides and the geology of the estuary affect water circulation in an estuary.
- Describe daily patterns of salinity changes in the estuary.
CONTEXT FOR USE
Teaching Time: 3 (55 minute) class sessions + homework
Organization of the Activity: This activity consists of 3 parts which help deepen understanding of estuarine systems:
- Tides in Chesapeake Bay
- Salinity as York River Flows into the Bay
- Interaction of Tides and River Flow
- Make copies of Student Reading — Estuarine Tides, Student Worksheet — Salinity and Tides, and if you will not be providing computer-access to the data, Student Data Sheet — Salinity and Tide Data for York River. (Note that the data on the Student Data Sheet are for a specific date: March 21, 2007.)
- Arrange for students to work with the animation and data, either in a computer lab or with a computer and projector. Bookmark the following sites: