Good Maps, Bad Maps (and a Volcano)
This past week I had a run-in with a Volcano. I wasn’t injured, just stranded in London for several days after a business trip due to a complete closure of British airspace after a volcano with an unpronounceable name erupted in Iceland. Upon my return, I received a very interesting email from my colleague Dean Hintz who had some great insights on the subject of maps and the Eyjafjallajökull volcano. Dean has graciously agreed to let me share these observations with you all – thanks Dean!
“Given the fallout of the Iceland volcano, the week of airspace closures and cancellations and the colossal mess that resulted, its worth looking back to see some lessons that people might hopefully learn, particularly in regards to a classic case of good and bad mapping. To be sure, this includes some hind sight because we haven’t encountered anything quite like this before.”
“Maps are like stats. They can be very deceiving or misleading if you are not careful. You can see in the image above that the orange ‘scope of ash’ covers a winding path around half the northern hemisphere, from eastern Canada to Russia. This is the same output from the forecast model that the closure of the entire European airspace was based on. Now take a look at the new red zone on the same map. This area starts at Iceland and extends about 700km SE over the ocean. This is accepted as the danger zone now as it does not include all areas of ash but only those with potentially damaging levels of ash, plus a significant buffer just to be safe. This new zone is about 5 – 10% of the old area.”
“So the next time you see a map, read some stats etc, don’t forget to ask the question as to where it came from and what exactly it means. New models, maps etc need to be challenged before we let them have such an impact. I think the first ‘scope’ map, combined with scary stories / YouTube videos about all engines failing (a plane flying through a thick visible plume within 100km of the Indonesian volcano) was enough to instil an emotional reaction in the regulators and the public so that they were loathe to question the old safety regulations (zero tolerance for even the possibility of trace ash).”
“Another more detailed example above is from Apr 20″ (click the map for full-size). “These maps come straight from the Eurocontrol website from the computer model used to justify the blanket bans. Also notice the revised map showing just the areas of higher ash concentration. Fortunately the airlines didn’t take it all sitting down and started to do their own test flights as a sanity check to see if the trace ash was as dangerous as predicted. Hard to believe that the output of the UK Met office’s computer model was used to close airports 3500 km away from a volcano with virtually no actual testing or verification (except a couple of Met flights in the UK). If verification and testing had begun within 24 hours of the ban, we may have had airspace open 3 days earlier and saved a lot of headaches and money.”
“One of the best way to measure ash on a wider scale without direct sampling is with LIDAR. Unfortunately this time round, there weren’t enough LIDAR scanning platforms and processing ability to properly track the ash.”
Great stuff by Dean. Hopefully next time LIDAR or other technologies will be able to be utilized to ensure that the data used to determine when to close airports is accurate. Safe’s President Don Murray is headed out to London this weekend. Don, if you do get stranded, remember that the Apple Store on Regent Street has great free wi-fi!
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Thanks for the insightful maps and thoughts. Learning to ask for sources and reality checking internet news and maps is something that many people are struggling with. I hope that the use of social media, whether it be Facebook, Twitter or otherwise, will make better information consumers of us all.
I wonder if it would be worthwhile to start a snopes for maps, you know… debunking maps that people assume are real… but are in fact urban legends. It could start with the whole Iceland is as large as the US issue..
Like all statistics, maps can have biases. A Snopes for maps sounds like a good idea. Looking at the Modifiable Areal Unit Problem (http://bit.ly/2EpDpa) alone could fill a whole site!
Of course we all know that Greenland is pretty much the same size as South America. THAT is not a myth!
Great post Michael! I was almost stranded in Wien, but Helsinki airport opened just in time. Bad maps lead to bad decisions. Lidar would have been the best solution for monitoring the ash concentration. I guess satellite microwave instruments could have also done the job, but perhaps there’s not enough research done.
FME Server would be a great solution for fast Lidar data processing, wouldn’t it? Different metorological institutes would submit their Lidar data to FME Server. The data would be integrated and quickly transformed to ash cloud models. Data integration and effective transformation is the solution, and it is one of the key abilities of FME.
Social media is a great way for information to spread rapidly, but it does pose problems about the original source and quality of that information. Thats why I like sites like wikipedia and wikinews which require that everything posted be adequately referenced. There’s also plenty of built in peer review to sanity check things. This type of news has more credibility for me than a site where I have no access to sources.
I like Guido’s idea for a snopes for maps. I wasn’t aware of the site before, but I did get a kick out of the ‘ban dihydrogen monoxide’ article. Maps can clearly be used to promote scare-lore like this, whether knowingly or not. The larger issue though is a general illiteracy in map comprehension. So far up to grade 6 my son has had little to no exposure to map reading or interpretation in school, with the focus being on ‘core academics’. At least with the proliferation of web mapping and gps, there’s a growing awareness of the its importance. Maybe we just need someone to create and circulate a really hilarious spoof map (DHMO vapor concentrations or?) to get people to think twice about what they are looking at ;>
Glad you made it home in time Lassi. I know that Scandinavia got hit worse than other parts of Europe. Interesting how Scotland and Ireland faced closures again this week. At least the mapping is more focused now so we don’t face Euro-wide closures again.
I found the use of LIDAR for ash detection fascinating. We are used to LIDAR for 3D terrain and built area mapping. However apparently LIDAR is particularly good at detecting ash because it reflects off fine ash particles that often cannot be seen with the eye even at moderate concentrations. This is essential as before we relied on flying aircraft through the ash to measure it, or we just relied on untested model projections. A good article on this from MeteoSwiss can be found at: http://www.swissinfo.ch/eng/index/Swiss_lasers_map_volcanic_ash_cloud.html?cid=8704734&rss=true
Great idea for an FME Server application to support LIDAR sharing and transformation. Part of the problem typically is that many models and sensors exist in isolation. Using only one model can give a distorted view of risk areas. Data integration can help by allowing analysts to build a combined view. Another problem is widely different data models. Weather scientists often use NetCDF, a multi-band volumetric raster format, as an output for their atmospheric models. LIDAR uses 3D point clouds. Thus satellite imagery, NetCDF and LIDAR all have radically different data-models, but all are needed to build an environmental picture rich enough to promote sound decision making. It takes tools that have deep schema modeling and transformation capabilities to integrate across diverse datasets such as these.