By catapulting to power an improbable alliance of the hard -left and nationalist far-right, Greece has shaken up Europe's political kaleidoscope and may have signaled the end of an era of centrist consensus.

With eight general elections due in the European Union this year, as well as regional votes, the earthquake in Athens may be a harbinger of further shocks to come.

Expect the unexpected in 2015 from Britain to Finland and Denmark to Spain as voters who have endured five years of economic crisis, falling real incomes and welfare cuts vent their anger, anxiety or apathy at the ballot boxes.