Capitalising on the search volume using Google Adwords:
Google saw flight queries increase 47% WOW at the time of ash crisis. Car hire queries also grew by 9% WOW as travellers sought alternative transport. There was a massive YOY increase in searches around European destinations (as this was the affected area). Long haul destinations saw a YOY decrease as travellers were finding these less attractive with the prospect of further ash disruption.
These ads are highly relevant and well thought out – ultimately searchers would be looking for info because they are worried about travel or looking for alternative arrangements and thats precisely what these advertisers are offering.