These estimated magma amount are only a third of a cubic kilometer, which is a fifth of the ejected volume at Mt St Helens. So not a huge concern thus far.
Still, the volcano's record includes the earth's largest known eruption in the past 10,000 years.
The amount you are referring to is the amount of ash plume ejected into the air. We are talking magma amounts here, voluminous lava.
The estimated amount of ash plume that came out of the infamous Eyjafjallajökull eruption in 2010, was less than that or 0.25 km
3 to be exact. So I would disagree and say that we do definetely need to worry. But let's hope this will only be like the one this morning, just lava well away from the glaciers. Or like the locals like to say "a tourist eruption"
An interesting fact, that in the last 500 years Icelandic volcanoes have erupted a third of the total global lava output. And one of the worlds largest lava flows came out of the Eldgjá fissure system, just south of the glacier 18 cubic km.
One of the most dangerous ones, Mt Katla is overdue for an eruption.. that vulcano has in history changed the global weather for a long time. It has been closely monitored now for many years. I has about 6 times larger ice cap on top of it than Eyjafjallajökull had. That one we do need to worry about, and it is not that far away from the current activity.