Ebola has broken out in West Africa. As of this morning, about 60 people have died of hemorrhagic fever in southern Guinea, with Ebola confirmed in more than a dozen cases — and the the virus may be spreading into neighboring Sierra Leone and Liberia. To help Doctors Without Borders and other responders with their work, the Humanitarian OpenStreetMap Team (HOT) has set up a crowdsourced tracing effort to quickly fill in the inadequate existing maps of the area.

Until commercial imagery is available, we’re helping with open data. One source is Landsat 8, which turned out to be useful for Typhoon Haiyan efforts as well, since it can be processed so fast. This is a region where the best available maps are often antiques from the colonial era, two generations ago. Even medium-resolution imagery is useful if it’s from this week. Landsat 8 shows major roads, rivers, overall land use, and most importantly settlements: all vital information for planners who need to know where to send supplies and in which directions the disease might have spread. Another useful source is a USGS purchase of high-res data:

Tracing for HOT is important and not very hard. If you want to learn, get involved today. If you have the skills, check into the tasking interface and start mapping some high-priority areas!