IsTremor
Power spectra of volcanic tremor often have structure appearing as horizontal stripes in spectrograms (left: e.g. from Katla, Iceland in 2011). This differs from one station to another and cannot reflect temporal harmonic behaviour of the tremor source, but can be explained (lower right) with interfering spectral harmonics caused by echoes (red), modulated by a broader source spectrum (black).
Characterization and location of volcanic, geothermal, water and anthropologic tremor sources.
Details
- Period: 2021-01-01 – 2025-12-31
- Budget: 500,000 SEK
- Funder: Rannis (Icelandic Centre for Research), Uppsala universitet
- Type of funding: research grant
Tremor is prolonged ground shaking, devoid of a clear onset and often vaning gradually. It is registered around volcanoes, often in association with eruption, but also in a weaker form around geothermal areas, near rivers and waterfalls and around human infrastructure (roads, industry etc). This project aims at characterizing different types of tremor/noise and locating their sources. Examples of tremor have been registered in various settings in Iceland and methods developed to locate their dominant sources. Can the different types of sources be distinguished based on their character (frequency content)? Volcanic tremor is often discussed as harmonic. This is often not warranted. Peaks in its amplitude spectrum may be better explained by scattering effects/echoes (see picture).
Cooperation partners
Veðurstofa Íslands/Icelandic Met Office (IMO)