Is It Safe To Be On A Cruise During a Tsunami?

As news starts to break about the recent earth quake off the coast of Russia and the resulting Tsunami warnings affecting the US Pacific coast and Haiwaii our thoughts and prayers go out to all of those affected.

But from a cruising perspective is it safe to be on a cruise during a Tsunami?

What Is A Tsunami?

A tsunami is a series of powerful ocean waves caused by large-scale disturbances, most commonly underwater earthquakes.

Unlike typical wind-driven waves, tsunamis involve the entire water column from the surface to the seafloor and can travel at incredible speeds across oceans.

In the deep ocean, tsunami waves have very long wavelengths (hundreds of kilometers) and small amplitudes (often less than a meter high), making them difficult to detect. However, as these waves approach shallower coastal areas, their speed decreases, their wavelengths shorten, and their height increases dramatically.

Upon reaching the shore, a tsunami can appear as a rapidly rising flood or a wall of water that inundates coastal areas, causing widespread destruction. The destructive power of a tsunami can be immense, capable of destroying buildings, infrastructure, and even carrying large ships far inland.

It’s important to remember that a tsunami is not a single wave but a series of waves called a wave train. The first wave may not be the largest or most destructive, and dangerous conditions can persist for several hours or even days after the initial impact.

How Rare Are Tsunami’s?

The good news is that Tsunami’s that cause damage are a relatively rare occurrence. In saying that the Pacific region is one of the areas with the highest incidence due to its geological make up and propensity to have earthquakes.

There are two types of tsunami you need to consider.

• Local Tsunami – These occur near to shore and as such are much less powerful. They can cause damage but it is unusual for them to cause loss of life. These type of tsunami occur an average twice per year.
• Distant Tsunami – These are tsunamis generated far from the affected coast, and they are less frequent, occurring about twice a decade. As the water enters the shallower sea bed nearer coast the waves gain height very rapidly and can be extremely destructive and dangerous to property and life.

What Happens To A Cruise Ship Caught In A Tsunami?

Its important to remember that although tsunami’s can occur quite frequently (Local Tsunami’s) they are only really at risk from Distant Tsunami’s which are a much less frequent occurrence (on average twice a decade)

When considering the impact of a Tsunami on a cruise ship the most important consideration is where the ship is located. You would think that the safest place to be would be in port where the ship can normally be protected from high waves. For a Tsunami the opposite is the case the most dangerous place for a ship is to be in a port or near land.

The reason being that tsunami’s really become dangerous as the water transitions from deep sea to much shallower coastal regions, which can result in a wall of water overwhelming the area where it makes land.

The standard procedure for all ships that are caught in a Distant Tsunami is when they are close to the epicentre to move way. If they are in port to set sail immediately the warning has been issued. To navigate to a depth of at least 150ft at which depth the wave impact would negligible and passengers wouldn’t notice.

This is why during the current tsunami event when the alarms were raised in Hawaii, there were reports of cruise ships leaving port early and leaving passengers stranded on land.

This is standard procedure for an incident as this type as the only real risk to a cruise ship is if it is caught in shallower water. With tsunamis capable of moving at 500mph they need to move as quickly as possible.

Conclusion – Is It Safe To Be On A Cruise During a Tsunami?

The good news is that if you are in deep water its very unlikely that you will even notice that you have been involved in a tsunami incident.

If you are in port and onshore when the alarm is raised there is a chance that you could get stranded as the ship will sail as quickly as possible to reach deep water.

Since the tragic tsunami of 2004 the early warning systems are much more sophisticated ensuring those on land have the required time to get to higher safer ground. So although tsunamis can be terrifying where they hit land hopefully we are able to mitigate the risks much better than before minimising the threat to life whist accepting they can still wreak a awful lot of damage.