Helgi Bjornsson. Visir/Fridrik Thor Halldorsson

Bridge of Skeidararsandur in 1996. Visir/Sigurjon Olafsson

The seismic activity in Bardarbunga on the Vatnajokull glacier is very powerful and therefore full reason to expect a volcanic eruption according to a specialist at The Icelandic Meteorological Office (IMO). The aviation alert status has been updated from yellow to orange which is the second highest status meaning that the volcano shows „heightened or escalating unrest with increased potential of eruption.“ The highest alert status, red, means that either an eruption is imminent or under way.No visible signs are of magma making its way to the surface close to Bardarbunga. Seismic activity is still very real with well over one thousand earthquakes measured during the last three days. The magma seams to be moving away from Bardarbunga, heading northeast. Click here to see a live webcam of Bardarbunga volcano . It's placed on the mountain Grimsfjall which is approximately 30 kilometers from Bardarbunga.Kristin Jonsdottir, a seismologist at the IMO, expects the magma to be at a depth of somewhere between three and seven kilometers. The largest earthquake measured during the last few days was of size four. It was measured last night."It's the largest earthquake measured in the area since the eruption in Gjalp in 1996 . There's full reason to expect an eruption,“ says Jonsdottir. Although the biggest worry abroad focuses on disruption in flights domestically Icelanders worry about serious floods.Helgi Bjornsson is Icelands most respected glacier specialist. Should an eruption occur very soon, a flood of a similar scale like the one in 1996 is likely according to Bjornsson. Three bridges in Skeidararsandur on the south coast were completely damaged. One of the bridge is part of route one, Iceland's main highway which runs around the country.The intense seismic activity that started on 16 of August at Bárðarbunga persists. Very strong indications of ongoing magma movement, in connection with dyke intrusion, is corroborated by GPS measurements. There are currently two swarms: one to the E of Bárðarbunga caldera and one at the edge of Dyngjujökull just E of Kistufell. At 2.37 am on the 18th a strong earthquake (M4) was located in the Kistufell swarm.This is the strongest earthquake measured in the region since 1996. As evidence of magma movement shallower than 10 km implies increased potential of a volcanic eruption, the Bárðarbunga aviation color code has been changed to orange. 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 (jökulhlaup) and ash emission. The situation is monitored closely.