page_title: Earthquake Network
section_title: Network size and geographic distribution
hierarchical_section_title: Earthquake Network / Network size and geographic distribution
caption_attribution_description: English: Smartphone network in Santiago area on December 5, 2015.
context_page_description: Earthquake Network is a research project that aims to develop and maintain a crowdsourced smartphone-based earthquake warning system at a global level. The system uses the on-board accelerometers in privately-owned smartphones of volunteer participants to detect earthquake waves. When it detects an earthquake, it issues an earthquake warning to alert people who the damaging waves of the earthquake have not yet reached.
  The project started on January 1, 2013 with the release of the homonymous Android application Earthquake Network. The author of the research project and developer of the smartphone application is Francesco Finazzi of the University of Bergamo, Italy.
context_section_description: The number of smartphones in the network is highly variable as users can install or uninstall the Earthquake Network application at any time. Additionally, the number of active smartphones (not in use and connected to a source of power) constantly changes during the day. Globally, the total number of smartphones with the application installed is around 750,000 (September 2017) and the number of active smartphones ranges from around 30,000 to around 120,000 depending on the hour of the day. The geographic distribution of the network nodes is given in the following table.
caption: Smartphone network in Santiago area on December 5, 2015
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