The world airline network divided into three parts.
The bottom layer is the Periphery with airports having a zero clustering coefficient. These airports reveal the peripheral world. The top layer is the Core with airports that form the nucleus of the t-core, t = 387. Nodes in the t-core are part of at least t triangles. This layer shows how well connected some of the major economic hubs of the world are. The intermediate layer is the Bridge with all the remaining airports that act as bridges to connect remote locations to global hubs. All maps are produced using Gephi28.