The recommended response during and after an earthquake abroad is no different from the behaviour recommended in the event of seismic activity in Switzerland. When staying in coastal areas you should pay special attention to the possibility of tsunamis. If you feel seismic tremors on a flat stretch of coast, move to higher ground inland as quickly as possible. Even more distant earthquakes can cause tsunamis close to where you happen to be. Heed and follow the instructions issued by the local authorities and find out in advance about local tsunami warning systems and escape or evacuation routes. Leave your place of refuge only after the local authorities have sounded the all clear, since more waves may follow initial ones, sometimes only after a lengthy time lag.
Here is an overview of the various official tsunami warning service providers: itic.ioc-unesco.org