15 – Coastal Processes Exercise. Part A: Wave Refraction & Diffraction

Instructions

Google Earth (Links to an external site.)Links to an external site.) where examples of wave refraction and diffraction can be observed and their images used to help explain the process. The two questions focus on writing a description of each phenomena, aided by the features visible in a chosen image.

The following locations (name and latitude, longitude) may be helpful in answering the first question:

• Ipanema beach in Rio de Janeiro (22° 59′ S, 43° 13′ W) – image shown as Example 1 below.
• South coast of Trinidad (from about 10° 04′ N, 61° 39′ 20″ W to about 10° 05′ N, 61° 49′ 22″ W)

Similarly, the following locations may be helpful in answering the second question:

• Shingle Island in the Laccadive Sea (9° 15′ 00″ N, 79° 14′ 00″ E) – observed in the 8/8/2010 image shown as Example 2 below.
• Off the coast of Venezuela (10° 55′ 54″ N, 68° 15′ 42″ W) – observed in the 4/2006 image

Example 1: Wave refraction at Ipanema beach in Rio de Janeiro

Example 2: Wave diffraction at Shingle Island in the Laccadive Sea – observed in the 8/8/2010 image.

Question 1 5 pts

Explain the process of wave refraction along coastlines making explicit use of images from Google Earth to illustrate your answer.

A strong answer will designate locations according to latitude & longitude in Google Earth that provide visual complements for the explanation of wave refraction. Specific reference will be made to aspects of the features in the image(s) – e.g. apparent bending of waves in shallow water – that exemplify the process.

Examples of wave refraction include:

• Ipanema beach in Rio de Janeiro (22° 59′ S, 43° 13′ W) – shown below.
• South coast of Trinidad (from about 10° 04′ N, 61° 39′ 20″ W to about 10° 05′ N, 61° 49′ 22″ W)

Question 2 5 pts

Explain the process of wave diffraction along coastlines making explicit use of images from Google Earth to illustrate your answer.

A strong answer will designate locations according to latitude & longitude in Google Earth that provide visual complements for the explanation of wave diffraction. Specific reference will be made to aspects of the features in the image(s) – e.g. interference of waves associated with waves around islands – that exemplify the process.

The following locations may be helpful in answering this question:

North and South Islands of New Zealand (35° 10′ 00″ S, 173° 06′ 00″ E and 41° 31′ 00″ S, 174° 05′ 00″ E, respectively)

Shingle Island in the Laccadive Sea (9° 15′ 00″ N, 79° 14′ 00″ E)