Three big earthquakes have shaken the area of an Icelandic volcano, local media report, as some two hundred emergency workers and other professionals prepare for a massive eruption.  

Bardarbunga is Iceland's largest volcanic system, located under the ice cap of the Vatnajokull glacier in the southwest of Iceland. It is in a different range to Eyjafjallajokull.

There has been intense seismic activity at Bardarbunga since Aug. 16 and the aviation industry is readying for potential disruption on the scale of the 2010 eruption of the Eyjafjallajokull volcano, whose ash cloud shut down much of Europe's airspace for six days, affecting more than 10 million people and costing $1.7 billion US.

The largest of Thursday's quakes was 4 in magnitude and took place at 1100 am local time, broadcaster RUV said, adding that almost 2000 earthquakes had been detected in the Bardarbunga area in the previous 48 hours. 

Emergency service workers and others gathered in the area on Thursday to review plans in the event of a massive natural disaster.

"We're here to talk to the local police chief and his officers and to the response teams to look at the situation to see if there's anything we can do to help. I think that we are well-prepared in case of an eruption," Iceland's chief of police, Haraldur Johannessen, said, outside the briefing room.

Tourists were continuing their holiday in Iceland on Thursday, including at the scenic spots of Husavik and Dettifoss, both to the northeast of Bardarbunga.

But some have changed their itineraries due to news about the seismic activity.

"Well actually we were supposed to try to travel to Askja, the crater, today, but since we heard that two days ago we changed our plans yesterday," tourist Stefan Alfandairi, said, referring to a volcano caldera near to Bardarbunga.

Iceland scientists were poring over the seismic data, with one central fear focusing on flooding which would be created as a massive eruption melted the Vatnajokull glacier which is up to 800 metres thick.

Naturalists managing the scenic Dettifoss waterfall believe that a large-scale flooding with debris could cause a collapse of the fall, disrupting the area's national park, but that there will be enough time to evacuate tourists.

"Yes we think that compared to the time that we've been given to respond, scientists have agreed that we have been given a lot of time and if the pace of the water flow starts to increase then we think that we have enough time to respond to that kind of situation," Hjorleifur Finnsson, park manager at Vatnajokull National Park, said.

Iceland's civil protection agency issued an evacuation order for an area north of Bardarbunga on Aug. 19.