Figure 2
From: Early warnings of COVID-19 outbreaks across Europe from social media
source software QGIS 3.10 LTS (https://qgis.org/it/site/).
Geo-localization of pneumonia-related tweets posted across Europe since December 2019. (a) Number of users discussing pneumonia between 15 December 2019 and 21 January 2020, after filtering out press releases and news accounts. (b) Relative variation in number of users discussing pneumonia between winter seasons 2019 and 2020. The maps were generated using the open-
