These reports indicate that the sequence of events in 1918 is indeed typical for Katla, with earthquakes in the hours before the eruption, and jokulhlaups following after a few to 12 hours. Katla has done silicic eruptions as well, with the large Vedde ash eruption as a good example, but even though these account for 5-10% of its eruptions, they have not happened in the last 1500 years. The large effusive Eldgja eruption occurred only 20 years after a normal Katla eruption: the deep large magma source which fed Eldja is apparently not affected by or directly involved with the summit eruptions.