Producing Radiation Maps - Participatory Mapping: New Data, New Cartography - page 99

was established for alternative data explains why, right after
the event, many cartographers used government and
industrial data in their mapping mashup. However, the
cartographers' attitude to the available data sources changed
as seen in the example of Safecast. Indeed, while the
association first launched a map which brought together all
the available data, its members soon started focusing on
creating a radiation-measuring network large enough to
facilitate doing without any other data sources (Figure 6.5).
The legend on the first map reveals the large number of
different data sources used. In this respect, the map is
similar to other radiation maps created in response to the
accident and which used data from MEXT, Pachube or the
prefectures (Table 6.1, for instance map no. 3 or 10 28 ). As
Pieter Franken (co-director of Safecast) stresses, the essence
of the association is to foster radiation monitoring after
the events of March 11, 2011 and to aggregate and publish
the results together.
However, their scope was challenged by the lack of Geiger
counters. The immediate solution for the cartographers was
to extract and to aggregate all the data available online. As
these data were still riddled with pitfalls, it constituted a
motivation for the organization to set up their own sensor
network capable of providing a satisfactory level of cover of
Japan:
When we started scraping the data, we saw there
was limited data available, and mostly in specific
location, so in order to get information around the
area that was affected we had limited data even if
they were aggregated. So over the month to come,
the government put more measurements points, if
you zoom out on the map, it looks like there are
many measurements, but if you zoom in, you see
there are huge stretches of no measurements
28 Reference to the corpus of maps, see Table 6.1.