Gunnar Sigurdsson of the Icelandic Meteorological Institute has warned of water levels tripling in the River Gigja, in less than a day. The water that flows into the Gigja, on the Vatnajoekull glacier in eastern Iceland, comes from an icy lake in the crater of the Grimsvoetn volcano.
The glaciers on the icy lake have melted because of a recent increase in thermal temperatures. The crater has filled up and the spill over has caused a river-run. Thorunn Skaftadottir, a geophysicist also with the Icelandic Meteorological Institute, explained a "river-run":
When a river-run occurs, the pressure, in this case, in Grimsvotn, decreases, and with less pressure, there is a chance of an eruption from the volcano. This is not guaranteed, since an eruption can only happen if the volcano has collected enough magma
Over the past 48 hours, the Meteorological Institute has also registered strong seismic activity in the area, and three moderate earth quakes ranging from 2.7 to 4.0
on the Richter scale, reports Yahoo/AFP News.
When the Eyjafjallajokul volcano erupted in April, it dispersed a massive cloud of ash which affected more than 100,000 flights and eight million passengers. However, Keflavik Airport spokeswoman Hjordis Gudmundsdottir said, "It is near impossible to say if Grimsvotn erupts whether it will have an affect on air traffic at all, If it is an ash eruption, then it would affect air traffic, but only if it is a strong eruption with ash clouds reaching significant heights, it will also depend on wind, so at this point it is hard to guess".
The volcano eruptions in Iceland spew lava or ash. Ash in the atmosphere can cause the jet engines to clog. Skaftadottir meanwhile said that any eruption from Grimsvotn, "would be an ash eruption". Although he points out it may be smaller than the Eyjafjallajokul volcano.