What causes Tsunamis

Tsunamis. How are they caused?tsunamis

Tsunamis can be generated by various means including seismic events, like earthquakes, volcanic eruptions, landslides (including those occurring underwater) and some weather systems, which can generate what are often called ‘meteotsunamis’, for instance from a sudden drop in air pressure.

What is the tsunami risk to the UK?

Although tsunami risk to the UK is low, studies have suggested that an earthquake emanating from the Azores-Gibraltar fault zone is the most likely source of a tsunami that would affect the UK coastline.

What are the warning signs of a tsunami?

Earthquake – If you are at the coast and experience an earthquake, it may have caused a tsunami, so you should make for higher ground or inland. Note that not all tsunamis will be preceded by an earthquake.

Unusual sea-level changes – If the sea suddenly recedes, exposing the ocean floor, or there is an approaching wall of water, it may be a sign of an approaching tsunami. You should escape immediately to higher ground or further inland. Be aware that the first wave in a tsunami wave train may not be the largest.

Ocean roar – a roaring sound offshore, like that of a jet engine, might indicate an approaching tsunami.

In some countries with a higher tsunami risk, street signage and loudspeaker systems may be in place to advise the public of how to respond to a tsunami event.


Tsunami events occur infrequently in the UK, but it is nevertheless important that the public is aware of the warning signs, especially if they often travel overseas to tsunami-prone areas. A sudden drawback of the ocean or an approaching wall of water and a load ocean roar can all signify an imminent tsunami, so you should move to higher ground or inland.

To mark World Tsunami Awareness Day on 5 November 2018, NOC scientists have prepared this Q&A feature on potential tsunami risks to the UK and its citizens.

SISAC organise Skill Developement Courses throughout the dive year to suit all qualifications. We welcome non-members to join us. Why not contact us for a schedule of the next courses. Call 01480 708029 or complete the contact page.

Comments are closed.