Final answer:
A tsunami can be caused by underwater A. earthquakes, B. volcanic eruptions, and C. landslides into the sea, such as rockfalls. The speed of a tsunami wave and its frequency determine the distance between wave crests.
Step-by-step explanation:
A tsunami can be caused by various geophysical events. Specifically, tsunamis are usually triggered by underwater earthquakes that displace large volumes of water, but they can also result from volcanic eruptions and landslides into the sea, including rockfalls. When the force of these events is strong enough, they can push water above sea level and create a series of powerful waves that travel great distances across the ocean at high speeds. Once these waves approach coastal areas, they lose speed but increase in height, potentially causing significant damage upon impact.
The tragic 2004 Indian Ocean tsunami, triggered by an incredibly powerful earthquake, is an example of the devastating impact that such a natural disaster can have, claiming over a quarter million lives. In other instances, tsunamis have also been generated by volcanic eruptions and landslides, each capable of generating waves that carry the potential for serious destruction. The theory of plate tectonics explains the occurrence of these geological events, as the movement and interaction of tectonic plates lead to earthquakes, volcanic activities, and changes in landmasses that can result in the creation of tsunamis.
CHECK YOUR LEARNING: If a tsunami travels at 600 km/h and has a frequency of 4 waves per hour (one wave crest every 15 minutes), the distance between wave crests would be 150 km at sea (600 km/h divided by 4 waves/h).