According to Jonfr.com, there was a new harmonic tremor in Katla volcano.
This harmonic tremor has two sources. Hydrothermal activity under the glacier, or magma moving deep inside Katla volcano (without creating many earthquakes in Katla volcano). It is unclear what is the case at the moment. This spikes are so far not related to glacier floods from Katla volcano. But that sometimes also happen without an eruption being involved. It is impossible to know what happens next. But it is also important to be aware of the fact that earthquake season is starting in Katla volcano. But that is normally from end of June to beginning of October (or when it starts to snow again in Iceland). So more earthquakes are going to be seen this summer also because of more SIL seismometers around Katla volcano.
Few days ago an earthquake swarm did start in Presthnjúkar volcano. This earthquake swarm is entirely tectonic in nature. There is nothing that suggests that this earthquake swarm is connected to magma movements inside Presthnjúkar volcano system. So far this earthquake swarm has been slow and small. But the largest earthquakes have gone up to ML3.3 in size according to the Icelandic Met Office.