The tremors, measuring 3.9, 3.2, 4.7 and 4.7 on the Richter scale, struck the 6,590ft Bardarbunga volcano over several days last week.
Páll Einarsson, a volcanology expert at the University of Iceland, said the latest quakes are part of a series that have been “in progress for two years” and a sure sign of a pressure build-up in the volcano’s magma chamber.
He told DailyStar.co.uk the volcano, which is hidden under the ice cap of the Vatnajökull glacier, is “clearly preparing for its next eruption” within the next few years.
The 10,000-year-old volcano spewed out large volumes of sulphur dioxide during its last seven-month eruption between August 2014 and February 2015.
Although the eruption did not disrupt flights, the emissions impacted air quality in Iceland, leading to health consequences across the country.
The warning follows the 2010’s explosive eruption of Icelandic volcano Eyjafjallajökull, which threw thousands of tonnes of mineral ash into the air.
The ash cloud grounded flights across the word and left more than 10 million air passengers stranded.
It is estimated the crisis cost the European economy around £4 billion.
Experts say a similar scenario could unfold if Bardarbunga – one of the most active of Iceland’s 130 volcanoes – were to erupt.
Dr Gunnar Guðmundsson from the Icelandic Met Office said there ware no signs it of an imminent eruption.
He said: “Probably in the coming weeks there will be some more earthquakes. We cannot predict but it’s unlikely Bardarbunga will erupt as a result.”
Dr Simon Day, of University College London, said: “Activity could precede a large explosive eruption and consequent widespread ash fall but it is statistically unlikely.
“It’s not very likely that the current activity will lead to an eruption breaking the ice or erupting along the rift zone.
“So, a lot more has to happen before the current seismic activity develops into a major eruption and the chance of it doing so is statistically quite small, of order 1 in 100.”