Tsunami Early Warning Information Graphic


Yep - they get it in Japan.

When the recent 6 metre tsunami hit the Samoan region, killing 189 people, there unfortunately wasn’t time to warn their people.

But there was time to warn their neighbours in the South Pacific.

We failed.

New Zealand had several hours to crank-up the tsunami warning machine. The police did their best to round up people on the shoreline, but apart from that all we got was out-of-date news reports, government websites which were light on detail and the internet rife with speculation and rumours.

In New Zealand SMS (text) messages warning people in high-risk areas arrived 3 hours too late. How many people on the East Coast of New Zealand could have been killed if this was the big one? Potentially thousands.

My previous article covered how bad the information out there was at representing where the tsunami could strike, the risk and what to do. The graphics which were available were highly technical, easy to misinterpret and in most cases was retrospective data of what had actually occurred – not predictions of what was coming.

And we have to take into account human nature. In New Zealand when we hear a tsunami is coming a fair number of us just assume it’s yet another false alarm. Hundreds even go down to the shoreline to watch it coming in.

Why? Saying “go to higher ground” isn’t specific enough. Some will think that means the big sand-dune a few metres from the shoreline.

I believe we need to give people a clear message at a glance, and just enough detailed information that they’ll take it seriously.

So, while I don’t claim to be a tsunami expert, I decided to have a go at creating a ‘general public’ information graphic which could be populated with data in real-time (or by hand and published online within minutes).

I encourage your feedback, or if you are a designer, have a go at improving on my design and let me know when you do.

Here’s my first attempt (click on the image to enlarge) or download the PDF (84KB) if you want a closer look.


The left panel shows a regional breakdown of the risk level, how high/inland to go and the deadline:


The map shows the risk level, how high/inland to go and the deadline for the major population centres:


The modular design allows the information graphic to be easily reformatted for different layouts. Here’s a snap-off of the map on it’s own:


And here’s a snap-off of the regional warnings:


Information Components

Good idea.
Good idea

The purpose of the graphic is to act as an early warning system to explain the following things I thought most people would be interested in:

  • Earthquake magnitude.
  • Wave height.
  • Arrival location(s).
  • Arrival time(s).
  • Power of the wave (extent of inundation).
  • How high I need to go up or/and how far inland.

Earthquake magnitude is easy, I included that.

Wave height is variable and actually a misleading factor as people wrong assume a small (say 3m) wave is not dangerous. It actually depends on the power or force of the tsunami – a small tsunami could still go a long way inland and cause devastation. So I deliberately left wave height out.

The other questions I have done my best to answer in the graphic.


The extent of inundation was hard to represent in “birds-eye view” graphic as it depends on so many factors (such as being by a river estuary).

This could work if the map was interactive, like a Google Map where you could zoom into your region and see an overlay of the areas which are likely to be affected. I’m sure this sort of thing is coming.

Colours to Represent Risk

Another aspect I struggled with was the use of colours to represent risk.

At first I used the traditional red/orange/yellow to show risk levels. I decided this wouldn’t be useful for people with red/green colour blindness (the most common form of colour blindness).

I felt that using of shades of blue further emphasised water smashing into the shoreline, so this won in the end.

Red/Orange/Yellow or shades of Blue?



Your Thoughts?

Says it all.
Says it all.

Whether you’re a tsunami expert or not I’d love your feedback.

Keep in mind that the intention of this Information Graphic is to act as one way to communicate the risk and guide people to take action.

I realise it’s imperfect as the risks can be hard to assess due to dozens of complicating factors. But in all I believe it’s better than ‘almost nothing’ – which is what we get every time a large earthquake hits the Pacific.

PS: Thanks to Click Suite who unknowingly allowed me work-time to design this graphic last Friday while my bosses were holidaying in Fiji (I was thinking of you insanely relaxing on a beach during the tsunami season!)

9 responses to “Tsunami Early Warning Information Graphic”

  1. Zef Avatar

    See also the comments in the original post over at Click Suite

  2. Brian Avatar

    Hi, I’d be interested in chatting with you about this further if you like. I think the red/orange/yellow version is easier to distinguish than your proposed shades of blue idea.

    Brian Shiro
    Geophysicist (and webmaster)
    NOAA Pacific Tsunami Warning Center

  3. Zef Avatar

    Thanks for the feedback Brian. I’d appreciate your ideas and a ‘realilty check’ on what’s possible. Will be in touch!

  4. Zef Avatar

    Klaus commented the following at the original post over at Click Suite

    Hi Zef,

    This is good stuff. In regards to getting the information across in a quick and universal way: I have to admit that by the first look I wasn’t sure if the arrows indicate the wave-direction and height. Anyway, I think this is just a matter of seeing the graphic for the first time – once you’ve read it it is easy to understand and gives a good indication what to do.
    On aesthetics: I think the ripples on the graphic are too subtle to work in an information graphic. bold blue lines instead of white may have more impact. (Don’t get me wrong: It ticks all boxes in sense of good graphic design!) I suggest to point out the seriousness of a Tsunami (Uuuhm, does that make sense?).
    Now I’m keen to get my fingers dirty too, hope to find the time… Will keep you updated!

  5. Zef Avatar

    Steph commented the following at the original post over at Click Suite

    Hi Zef – I think this graphic is very simple to understand – great job! I personally prefer the orange/red colouring than the blues – I didn’t notice that there was colour coding initially with the blues. I think that as blue is used so often in mapping already it’s not clear that you are using it to indicate risk. Also – the orange/red colouring is such a cliche now for indicating risk that you should probably stick with it. Not sure if the red/green colour blindness is really an issue because the varying shades will still be distinguishable as much as the varying blues are. Presumably people who suffer from this issue may already be as used to the cliche colours as everyone else and the use of blue may escape them too?

    That’s my preference anyway 🙂

    Can you make it fit an iphone for me as well?

  6. Zef Avatar

    Magnus via Facebook commented:

    What a great idea and design! A couple of comments: Maybe too much black in the boxes on the map – the white text and arrows are a bit lost (or replace the black with the appropriate shade of blue)? And on the graphic at top left – would adding arrows labelled “up” and “inland” beneath the running figure add clarity, or maybe be overkill? Regarding… Read more using blue vs red/orange/yellow – I’m colour blind but didn’t have any problem differentiating on the example – but blue looks better :o) Hope this is helpful.

  7. Zef Avatar

    Found out that Australia have a similar approach already in action over here http://www.bom.gov.au/tsunami/about_tsunami_warnings.shtml – why doesn’t New Zealand have this?

  8. Nick Avatar

    You’ve tackled a tough one here Zef. Share traders and air traffic controllers are used to processing 6 sets of data at once, but us mere mortals, partcularly if having to make a critical decision are less able.

    People recognise colour before they recognise shape or text, so using colour for the level of risk is smart.

    Other people who are waiting for waves to hit are surfers and perhaps some leads could be taken from surf weather maps.

    If you’re going surfing you need to know a few variables and there is a strong hierarchy of importance. (if there’s no swell you don’t care which way the wind is blowing)
    Size of swell
    then direction of swell
    then wind direction
    then wind strength
    then tide time.
    then it’s down to local knowledge to work out which spot will be best in those conditions.

    Some websites do better jobs than others at combining this information, but you’d make alot of surfers happy if you were to apply some of your logic to their forecast maps.

    Here’s a couple of regularly used services and how they represent the data.



    Great work. Nick

  9. Zef Avatar

    In the news today the New Zealand Civil Defence agreed they failed and have plans to fix the public warnings…

    The full story on the NZ Herald website