Wave Lab

From GeoClasses

In this lab we will look at coastal landforms. You will be given a large plastic container and some sand.

Contents 1 Directions 1.1 A 1.2 B 2 Examples 2.1 Create a tombolo 2.2 Longshore drift 2.3 Peninsula 2.4 Submarine terrace

Directions

A

• Place 2-3 cm (about 1 inch) of water in your container.
• Create a pile of sand at one end of the container.

Draw a sketch of the profile of the sand, both above and below the water. Explain is the slope steeper just above the level of the water?

B

• Create a peninsula in the middle of your container.

• Create some small waves, using your hand or a wave-maker, and gently erode the peninsula.

• Note
  • the way the sand grains on different parts of the peninsula move with the longshore current.
  • the shape of the waves as the wrap around the head of the peninsula.

Draw a sketch map of your landform. Be sure to note the submarine terrace and other features you observe.

Examples

Create a tombolo

This tombolo was created by Group 1 on April 12th 2005 by creating an offshore island and generating a longshore current with wave action. The wave direction is in the direction that the finger is pointing.

Tombolo.

Group 1.

Longshore drift

This group created a rectangular island and generated a longshore drift to demonstrate erosion and deposition of a spit.

Group 2.

Peninsula

This image shows the wave refraction around the peninsula.

Group 3.

Submarine terrace

After much ersosion, a submarine terrace is left where the peninsula once was.

Group 3.