"Usual" is worked out from the last 12 months; for the year, from the last 10 years (USGS counts).
Countries are ordered by the seismic energy their events have released, not by how many there were.
Each dot is an event (magnitude 4 and above) at its time and magnitude. The line behind is a simulated seismograph trace: it swings wider the more earthquakes an hour has and the stronger they are.
Days are counted in UTC. Daily figures merge USGS and EMSC; yearly figures come from USGS. The curiosities in the ticker come from Wikipedia.
Energy adds up every event of the year: one earthquake of magnitude 7 releases as much as about a thousand of magnitude 5. Each map zooms in on where the events were and shows up to the 100 strongest.