Fig. 4

Map of lightning activity in a 2 h period, detected more or less globally (coverage in South America and Africa by this amateur network is somewhat sparse of stations, which need only a small VLF receiver and an internet connection). A single recent strike is detected (lines) by stations from Japan to Australia and New Zealand, allowing its location in the Philippines—some 8000 km from New Zealand—to be reconstructed (circle) within a second or so. It is also apparent from this plot that there may often exist regions thousands of kilometers across where no lighting is present at a given time. Creative Commons license—by contributors to the Blitzortung network