Quoting: Anonymous Coward 35019861 did some manipulation of it..
[
link to makeagif.com]
that is an eruption underwater, or geothermal or something.
Quoting: Anonymous Coward 35001787 on second thought though, looking at GE, it seems there is an estuary there, so maybe a glacier flood off the big glacier is going on?
Quoting: Anonymous Coward 35001787 
I think both explanations well, but as yet there are no additional data is difficult to give preference to any of them.
purely speculative - I would have preferred the first explanation, that is, an underwater eruption.
Why?
First, a very pretty spot, and much like the what we have seen for a long time near El Hierro

Secondly, I think that we are not seeing enough volcanic activity under the glacier in the surrounding areas (tremor, and so on),
so you can expect the melting of large volumes.
Third, all known volcanoes there are far enough away from the source of stain,
and in addition, well-defined estuaries to collect such large amounts of melted water I do not see.
Well, except that there is some new crack was formed?

so while I would consider rather the first option (unless, of course, rule out any industrial discharges?)