Many people want to know how to identify a volcanic tremor when they appear. Here are few examples of volcanic tremors that I have seen over the past few years.
The volcanic tremor following the eruption in Grímsfjall in 2004.
Harmonic tremor spike in 2005, following a glacier flood in Skaptárkötlum in Vatnajökull glacier (they are in Hamarinn volcano).
I hope that this two examples show people what to look for when something is going on in Icelandic volcanoes. All images are from Icelandic Met Office web page.