Twenty small earthquakes around Sundhnúkagígar crater row
One possible explanation for the earthquakes is that magma movement stopped before a magma run occurred. mbl.is/Árni Sæberg
"We have seen this happen before, sometimes before an eruption, so this has happened before," says Steinunn Helgadóttir, a natural hazard expert at the Icelandic Meteorological Office, about the series of small earthquakes that occurred between Mt Sýlingarfell and Mt Stóra-Skógfell late Sunday night and Monday morning.
Between two and three in the morning, there was a series of small earthquakes of about twenty earthquakes between Mt Sýlingarfell and Mt Stóra-Skógfell. It was thought that a magma run was starting at Sundhnúkagígar crater row, and the Civil Defense met with the Icelandic Met Office during the night.
Other measurements did not give evidence of an imminent magma run, and it was decided that there was no need to react to the eruption, which began to calm down after three o'clock in the morning.
No other data provided evidence of a run
All the earthquakes were below one in magnitude and at a depth of three to six kilometers.
The tremors were in a similar location as there have been in the past at the start of magma runs in the Sundhnúkagígar crater series, but none were recorded there after four o'clock Monday morning.
The map shows the location of earthquakes between 2 and 4 Monday morning. Dark red lines are fissures on the Sundhnúks crater series from December 2023 to August 2024. The red line is the part of the fissure that was active the longest during the last eruption. The gray cover shows the extent of the lava formed in the last eruption from August 22nd to September 5th. The location of the eruption fissure and the lava bed is based on data from the image surveying team of the National Institute of Natural Sciences and The National Land Survey of Iceland. Map/Icelandic Met Office
"We are constantly monitoring all the data we have. Like Monday morning, it was only the seismic data that showed this wave, but no other data that gave evidence that there was something else going on," Helgadóttir says.
There were no signs of deformation of the GPS meters, fiber optic cables, or pressure changes in HS Orka's boreholes in Svartsengi, and an announcement from the Meteorological Office says that when magma has flowed from Svartsengi into the Sundhnúkagígar crater row, the measuring mentioned above devices showed clear signs.
One possible explanation
One possible explanation for the earthquakes is that magma movement stopped before a magma run occurred.
"That's what we're leaning towards, that there just wasn't enough power in it."
Benedikt Gunnar Ófeigsson, head of deformation measurements at the Icelandic Meteorological Office, said in an interview with mbl.is yesterday, however, it is not possible to claim that magma movement caused the earthquakes early Monday morning.
