On the morning of February 6, 2023, an earthquake killed more than fifty thousand people in Türkiye and Syria. I spent a week inside the edit history of the world's free map, reading what the internet did that morning. I haven't stopped thinking about it.
Below is the real map, zoomed in. The dashed building was missing on the morning of the earthquake. A stranger drew it that week. Now you: tap its four corners.
This is Kahramanmaraş, a city of half a million people, the way the map knew it that morning: 961 buildings. The rest was blank paper.
Why would a city of half a million people be missing from the map? That sounded impossible to me in 2023, so I went and looked it up, and the answer turns out to be money, twice.
Commercial maps are built where the money is. Google and Apple map roads because cars navigate them, and they map shops because businesses pay to be found. That works beautifully in London or Los Angeles. In a working-class Turkish city, and in the Syrian towns across the border, there is no ad revenue in knowing where each house stands, so no company ever paid to find out. The satellites photograph everything, but a photograph is not a map. Someone still has to look at the pixels and say: this shape is a building, this line is the road that reaches it.
The second reason surprised me more. Even where a commercial map looks complete, rescue teams mostly cannot use it. They can't download it onto a GPS unit and carry it into a zone where the internet is down. They can't count its buildings to estimate how many people might be trapped in a district. The data belongs to the company, and the license says no. OpenStreetMap is the exception, and it is the exception on purpose: it is the Wikipedia of maps, free for anyone to copy, carry, and analyse. When things go wrong, it is the map that gets used. It just has to be drawn first, by someone.
That morning, rescue teams were already in the air. They were flying toward a city the free map could not yet describe.
You cannot search rubble you don't know exists.
When a disaster hits, a small nonprofit called the Humanitarian OpenStreetMap Team does something simple. It takes the affected area, chops it into small squares, and puts the squares on the internet, on a site called the Tasking Manager.
Anyone can claim a square. A student in Manila, a nurse on her lunch break in Ohio. You do a twenty-minute tutorial, the site hands you a fresh satellite photo of your square, and you trace what you see. A roof takes four taps, the same four you just did. A road takes a line drawn along it. When your square is finished you mark it done and take another. Thousands of people do this at the same time, from their couches, for free. Even the satellite photos are part of the kindness: after a disaster, the imagery companies unlock their newest pictures of the zone so that volunteers can trace them.
And nothing lands on the map unchecked. Experienced mappers review the squares that beginners finish, straighten the wobbly corners, and sign them off. It is Wikipedia's old trick applied to geography. Many hands, and the hands check each other.
Every trace flows into OpenStreetMap, the free map of the world that anyone can edit and nobody owns. Rescue teams download it onto their phones and their GPS units. And suddenly the questions that matter have answers: which roads reach this valley, how many houses stood in that town, where do people actually live.
One detail I found moving once I understood it: the volunteers trace photos taken before the earthquake, on purpose. A map of what a neighbourhood held is a map of where to search it.
That is the whole machine: squares, taps, checks. Here is what it did in February 2023.
The ground tore at 1:17 in the morning, universal time. At 11:00, seven people somewhere in the world opened their laptops, claimed their squares, and began to trace.
By early afternoon they were forty. By evening, 176 strangers were drawing this one city in the same hour. Before the day ended they had traced 58,859 buildings across the earthquake zone.
Scroll. Everything green is a building a stranger just drew.
The earthquake. The map holds 961 buildings.
1,150 people spent it tracing rooftops.
The UN ran a mapping event and 400 more people showed up. By midnight: 1,653 people, 220,213 buildings across the region.
The task queue reached this neighbourhood. 6,720 buildings drawn here in a single day.
This patch alone: 961 buildings to 20,359. A city, drawn by people who will never see it.
By spring, at least 9,235 people had drawn more than two million buildings and 72,000 kilometres of road. Nobody paid them, and almost none of them will ever stand in the city they drew.
*"People tracing today" counts the whole earthquake response, not just this neighbourhood. Hashtag-tagged edits only, so every number is a floor.
Data that proves people are better than the internet makes them look. One visual essay a week, free.
The logs don't record names or countries, and I think that's fitting. Here is what the logs do record: for thirty days, the drawing never stopped. Every hour I checked, someone, somewhere, was awake and tracing.
I assumed Türkiye was a beautiful exception. It wasn't even the first time.
The heart of Port-au-Prince held two buildings on the free map. Strangers drew five and a half thousand in three months. The World Bank wrote that UN teams navigated the response on their work.
Buildings drawn around Kathmandu in ten weeks after the Gorkha earthquake, by six to seven thousand contributors.
310 people drew 32,450 buildings in the first two days after the Al Haouz earthquake, while the aftershocks were still coming. The full response: 5,524 people, 695,000 buildings.
The maps were not a gesture. Four organisations, in their own reports, on how they used what the volunteers drew:
routed aid logistics on the volunteer-drawn roads
coordinated rescue teams on OSM maps
used the data for rescue coordination
measured damage against the traced footprints
On June 24, an earthquake hit the hills west of Caracas. Volunteers opened the satellite photos the same day.
You need a laptop and about twenty minutes; a mouse helps. Make a free account at openstreetmap.org. Then go to tasks.hotosm.org, the same Tasking Manager the volunteers on this page used. Filter the projects by "beginner", and the site will walk you through your first building before it gives you a real one.
If a disaster is active, your square will be part of a response like the ones above. If the world happens to be quiet, the Missing Maps project keeps year-round tasks open for places that need a map before the emergency, which is when a map helps most.
You will be slow at first. Everyone is. But the building you trace on your first evening will still be on the map in ten years, and one day someone you will never meet may navigate by it. You already know the whole skill. It took you four taps.
Open the Tasking Manager →Two public archives: OpenStreetMap's full edit history (via HeiGIT's ohsome API) and the Humanitarian OpenStreetMap Team's statistics service (stats.now.ohsome.org). Every edit ever made to the map is timestamped and public. My queries are fixed in a script, and you can re-run every one of them.
They are 9,235 distinct accounts that tagged their edits with the official response hashtag #TürkiyeEQ060223. HOT's projects are volunteer efforts and HOT calls them volunteers. I can't audit every account, so I write "at least" and I show you the logs.
Because rescuers need to know what stood there before. The volunteers traced pre-quake satellite photos on purpose: a map of what a neighbourhood held is a map of where to search, and a baseline for measuring damage. The Red Cross used it exactly that way.
No. The hashtag counts miss anyone who mapped without tagging their edits, and the pre-2013 events (Haiti) predate hashtags entirely, so there I count buildings inside a fixed rectangle instead. Every number on this page is a floor, not a ceiling.
A 4 km sample of central Kahramanmaraş (36.90–36.95°E, 37.55–37.59°N). I chose it before pulling the data and it stays fixed through the whole page. Different rectangles give different counts; the shape of the story doesn't change.
· Sources: ohsome API, ohsomeNow stats, HOT one-month report, World Bank on Haiti.