Final answer:
Tidal waves and earthquakes can instantly end ship-to-shore communications.
Step-by-step explanation:
In ship-to-shore communication, there are two motions that can instantly end the communication:
- Tidal Waves: Large tidal waves, such as tsunamis, can cause severe destruction and disrupt ship-to-shore communications.
- Earthquakes: Strong earthquakes can damage underwater cables and disrupt the transmission of signals, leading to the immediate end of ship-to-shore communications.
These two natural phenomena have the potential to impact entire communication systems, affecting various regions and their ability to communicate with ships at sea.