An island 846 miles away from United Kingdom poses as a ticking time bomb far worse than the human-induced catastrophes of nuclear warfare and terrorism to its locals.

Authorities in Britain are mulling over necessary measures to prepare for the worst-case scenario in case a 'supervolcano' eruption in nearby Iceland occurs, a threat that has been considered as "one of the three highest priority national hazards faced by the UK."

The move came after a study commissioned by the UK government presented the dangers of the subsequent volcanic eruptions reminiscent to the eruption in Iceland's Laki fault system in 1783-84, where it ripped open and spewed lava and volcanic ashes that wiped out thousands of people not only in Iceland but in some parts of Europe as well.

For two consecutive years, UK has been plagued by the volcanic ashes the sputtered from Iceland's Eyjafjallajökull in 2010, and Grímsvötn, the most active volcano of Iceland, in 2011, causing major disruptions in air flights around North-Western Europe.

Greater danger, however, is expected should a 'supervolcano' unleash its wrath. Temperature will go to extremes, crops may die, and deadly clouds of sulphur dioxide will mix with air. This is one of the major concerns the UK Cabinet Office cited in its National Risk Register of Civil Emergencies 2013 edition that the government wants to address.

"Analysis of the geological and historical data about this eruption indicates that significant levels of sulphur dioxide, chlorine and fluorine were released over a number of months, causing visible pollution across the UK and Northern Europe which is thought to have resulted in mass crop failure and thousands of excess deaths," the UK Cabinet office said [pdf].

The report further revealed that 20 percent of Iceland's population then died from famine and disease while increased rate of deaths and respiratory disorders were recorded in France, the Netherlands, Italy and Sweden.

A Scientific Advisory Group in Emergencies (SAGE) was formed in 2012 to study the potential future eruption scenarios that might affect the UK. The government-commissioned study is an effort of top scientists from the British Geological Survey (BGS), the Met Office, Leeds and Bristol universities, the Centre for Ecology and Hydrology, government departments and other agencies and other academic institutes.

The report will be presented Saturday by Sue Loughlin, volcanology head at the BGS and also one of the researchers of the study, at the European Geosciences Union General Assembly in Vienna, Austria.

"There are a range of volcanoes across Europe (such as Santorini in the Aegean Sea and Vesuvius in Italy) whose eruption could have significant consequences in the UK," the Office added. "But volcanoes in Iceland are of most concern because of the active volcanic nature of this and the prevailing meteorology."

Iceland has around 30 active volcanoes, with eruptions recorded once every five years.

So far, the Civil Contingency Secretariat of the Cabinet Office responsible for emergency contingencies has developed models based on the scenarios, namely the UK Met Office's NAME Lagrangian dispersion model and the Centre for Ecology and Hydrology's EMEP4UK Eulerian model are both being used.