Final answer:
The correct answer to the question is that large icebergs calving from coastal glaciers create tsunami waves. These waves can travel at high speeds in the open ocean with long wavelengths, and their height can increase as they approach shallow coastal waters. Option a) is correct.
Step-by-step explanation:
Large icebergs that fall from coastal glaciers create tsunami waves. A tsunami is a series of sea waves typically caused by an underwater earthquake, landslide, or volcanic eruption, but can also be generated by displacements such as large icebergs calving from glaciers. When considering the dynamics of a tsunami, if it travels at a speed of 600 km/h and approaches a shore with one wave crest every 15 minutes, the distance between those wave crests at sea would be 150 km (600 km/h divided by 4 waves/hour).
It's important to note that while tsunamis can have incredibly long wavelengths, the height of a tsunami wave in deep water may be less than 30 cm. However, as it approaches shallow coastal waters, the wave slows down, and its height can increase dramatically, potentially causing significant damage upon reaching the coast.