The eruption of Iceland's under-ice Eyjafjallajökull volcano in April 2010 was powerful enough the ashes that plumed into the sky caused the cancellation of thousands of flights. A similar incident is feared to likely happen again as another Icelandic volcano threatens to erupt.

Seismic activities have been observed at  Bardarbunga volcano since Aug. 16 and an earthquake with a magnitude of 4.5 on the Richter scale, the strongest that rocked the region since 1996, occurred on Monday signaling a possible eruption and prompting the evacuation of residents living close to the volcano.

On Tuesday, authorities said that they are closing and evacuating the area due to the seismic activities at  Bardarbunga, a huge volcano sitting on Vatnajokull, Iceland's largest and most voluminous glacier. Bardarbunga is also a stratovolcano, the most deadly of all the types of volcano and is known for their explosive eruption. Scientists said that an explosion could result in the disruption of transatlantic and northern European flights, which happened with the eruption of Eyjafjallajökull.

"Presently there are no signs of eruption, but it cannot be excluded that the current activity will result in an explosive subglacial eruption, leading to an outburst flood and ash emission," the Iceland Meteorological Office said in a statement adding that it is closely monitoring the situation.

Just like Eyjafjallajökull,  Bardarbunga is an under-ice volcano. Bardarbunga sitting in a large glacier has raised concerns that an eruption would likely result in the spewing of large amounts of ash and steam as the magma from the volcano meets with the melting snow and water from the glacier. The melting of the ice is also feared to cause serious damage to infrastructure.

It isn't yet clear how many people have been moved because the area is remote but the country's emergency services were already placed on alert status. The Icelandic Meteorological Office has likewise raised the aviation alert to orange, the second-highest level in the aviation color codes that indicate the level of risks posed by a volcano to air travel.

"There is a risk of false alarm, but on the other hand we should try to be objective and say something immediately," Gísli Pálsson, an anthropologist from the University of Iceland, said. "The alarm signal is orange and rescue teams are preparing for eruption. This could either be outside the glacier, with floods to the north, or under the glacier, with risks for air travel."