“Geologists are currently investigating signs that magma is building up again under Bárðarbunga,” says Iceland website.
Bárðarbunga is the volcano under Iceland’s famous Vatnajökull glacier which erupted for six months in 2014-15.
An earthquake swarm on September 11 in Hamarinn volcano may be connected to Bárðarbunga, says Jón Frímann of jonfr.com
“That connection is unclear,” says Frimann, “but historical data suggests that once Bárðarbunga volcano gets erupting sometimes Hamarinn volcano does too.”
Thanks to Andrew Stranglen for this link