SKAFTAFELL, Iceland — Just north of here, on the far side of the impenetrable Vatnajokull ice sheet, lava is spewing from a crack in the earth on the flanks of Bardarbunga, one of Iceland’s largest volcanoes.
By volcanologists’ standards, it is a peaceful eruption, the lava merely spreading across the landscape as gases bubble out of it. For now, those gases — especially sulfur dioxide, which can cause respiratory and other problems — are the main concern, prompting health advisories in the capital, Reykjavik, 150 miles to the west, and elsewhere around the country.
But sometime soon, the top of Bardarbunga, which lies under as much as half a mile of ice, may erupt explosively. That could send plumes of gritty ash into the sky that could shut down air travel across Europe because of the damage the ash can do to jet engines. And it could unleash a torrent of glacial meltwater that could wipe out the only road connecting southern Iceland to the capital.
All of that could happen. Then again, it may not.
Such are the mysteries of volcanoes that more than four months after Bardarbunga began erupting, scientists here are still debating what will happen next. The truth is, no one really knows.
About 40 earthquakes have been observed in Bárðarbunga during the past 24 hours. A few were between magnitude 4 and 5. The largest occurred in the northeastern caldera rim at 13:36 yesterday of magnitude 4.4. A few quakes have been observed in the dike intrusion, all below magnitude 2. The eruption was visible on web cameras last night and seems to be of similar strength as during past days.
Volcanologist Thorvaldur Thordarson, who is nearby, says clear that the eruption has changed; the eruption is now spreading to a new fissures, closer to the Dyngjujokull glacier. Large new surface cracks have been observed there in the last days, and a small rift valley (graben) has formed, which extends under the glacier.
There are about 20 super volcanoes on the earth and activity continues to mount at Bardarbunga with reports now of over 500 earthquakes hitting the area since midnight of yesterday. The swarm has continued since August 20th. As the molten rock pushes up between plates, they move causing multiple earthquakes and allowing the molten rock to move higher.
Fractures, about four to six kilometers long, have formed north of Vatnajökull outlet glacier Dyngjujökull, northeast of Bárðarbunga, as reported byRÚV, visir.is and the Icelandic Met Office. Small calderas (also known as lows or cauldrons) have formed in the glacier and it cannot be ruled out that an eruption has started.