As thousands of passengers were left stranded for the fifth consecutive day because of the volcanic gas cloud, Reuters came up with three potential scenarios for the crisis.
Cloud clears swiftly
The volcano could cease erupting, simply stop emitting ash, winds could shift away from Europe or the gas cloud could be dispersed unexpectedly quickly - although so far none of these shows any signs of happening.
Airlines and air freight companies would immediately scramble to make up for lost time, repatriate and relocate passengers, aircraft and cargo.
• Airlines would still have lost some $200 million a day during the shutdown, the International Air Transport Association says.
• Even if the cloud clears, some travel will still be cancelled in the coming days. Some firms are asking employees to cancel non-essential European flights over the next seven to 10 days.
• Airlines might show greater interest in taking out cancellation insurance. German insurer Munich Re said on Friday it could offer such insurance easily if recent events produced the demand.
Cloud clears, eruption continues
Experts warn that as long as the eruption continues, the risk remains that a renewed outflow of ash or certain wind patterns could produce the same effect again in the coming months.
This time, airlines would be less taken aback but there would still be little they could do to prepare. The threat of a renewed shutdown might deter both business and leisure travellers from booking flights, holidays and hotels, hitting the industry even if the cloud itself never returned.
• Airline industry stocks could underperform as markets factor in a risk premium. Rail, road, sea cargo and teleconference firms could see an increase in demand.
• Firms might take on additional stocks to reduce their reliance on "just-in-time" resupply by air cargo.
• Any return of the cloud would again hit airline and travel stocks as well as potentially undermining regional growth.
• Much would depend on whether the current eruption triggers Iceland's nearby and much larger Katla volcano, further increasing the potential impact.
Cloud remains, Europe remains shut down
If the cloud remains stubbornly over Europe for a sustained period of time, perhaps weeks or longer, the travel sector would take a serious hit. Wider industries would also be affected from high-tech manufacturing to supermarkets and event organisers.
• This would be devastating news for the airline sector, possibly driving some of the weakest operators to the wall.
• Overall European growth might be affected, slowing the recovery from recession. Already heavily indebted governments would struggle to find the funds for support programmes. Europe might lag further behind the rest of the world in the global recovery.
• Teleconference, shipping, rail and road transport operators would benefit. So would airports just outside the cloud, suddenly in great demand from airlines and shipping firms as new hubs. That could benefit countries along the edge of the cloud including Ukraine, Turkey, as well as Portugal, Italy, Greece and Spain - the eurozone fringe economies worst hit by the financial crisis. Britain's Royal Mail is already shipping and trucking airmail to the United States to Spain for onward flights.
• Western military resupply flights to Afghanistan would be heavily affected. Western European troop contributors would become entirely dependent on the US for supplies and medical evacuation flights. US forces would also be heavily affected if they could no longer use their logistics and medical centre in Ramstein, Germany. This comes days after an uprising in Kyrgyzstan ushered in a pro-Russian government that may want the US to vacate its Manas airbase there, another key hub.
• Major international meetings may have to be cancelled, rescheduled or simply go ahead without senior European policymakers. That might further weaken Europe's geopolitical relevance at a time when it is already threatened by the rise of emerging economies and internal differences over dealing with the Greek debt crisis.