Within ISVOLC, an international team of more than 20 researchers from 11 partner institutions studies the effects of climate change on ice-retreat, associated glacial isostatic adjustment, and influence of these processes on seismic and volcanic activity, with a grant-of-excellence financial support from the Icelandic Research Fund. The project start date is 1 April 2023, and it has a duration of 3 years. The project is led by Michelle Parks at the Icelandic Meteorological Office, together with Freysteinn Sigmundsson at Institute of Earth Sciences, University of Iceland.
Glaciers in Iceland have been retreating since 1890 and climate change simulations predict that the majority may disappear within a few hundred years. Retreating ice caps change the subsurface stress field. Glacier covered volcanic systems are most affected, but also crustal conditions outside glaciers. The project combines volcanology and glaciology to address these environmental changes.
The project will create a unified database of volume changes of the Icelandic glaciers since 1890 at high spatial and temporal resolution, based on in situ and remote sensing methods, as well as models for climate and ice flow. Using this input, the project will build a three-dimensional glacial isostatic adjustment (GIA) model for the entirety of Iceland, considering a realistic lithospheric/mantle structure.
Eruption likelihood may be modified as a result of the ice retreat, as occurred during the Pleistocene deglaciation. More melt is estimated to form under Iceland because of ice-retreat. However, there are several uncertainties: i) if, how and when this new magma reaches the surface; ii) if stability of existing magma bodies is modified; iii) if deglaciation is already resulting in accumulation of larger volumes of melt within crustal reservoirs; iv) how induced variations in the stress field may affect both future volcanic and seismic activity. ISVOLC will address these research questions using four active volcanoes and two major fault zones as test areas within Iceland.
The Glacial Isostatic Adjustment (GIA) models will be used to estimate magma generation due to pressure release in association with the present-day ice retreat. Combined crustal stress changes from GIA and magma movements will then be used to infer the influence on stability of existing magma bodies beneath these volcanoes and for determining the effect on fault zones. Simulated scenarios of continued ice mass loss will be used to assess future changes in volcanic and seismic activity, for improved understanding of natural hazards.
ISVOLC study areas and processes: a) Map of Iceland with glaciers (white) and fissure swarms (yellow), showing target areas: Katla (K), Askja (A), Grímsvötn (G), Bárðarbunga (B), South Iceland Seismic Zone (SISZ) and Tjörnes Fracture Zone (TFZ). b) Schematic view of processes involved at subglacial volcanoes as a result of deglaciation. c) Vertical displacements (upper) and velocity with uncertainty in selected periods (lower) at GNSS station JOKU (marked as black triangle in fig. a) due to GIA. Notice irregular velocity during the full period; a topic of study in ISVOLC.
The ISVOLC hypothesis
The project addresses the specific hypothesis that glacier mass loss is already producing excessive melt, affecting magma migration beneath Iceland, and stress changes are affecting the stability of existing magma bodies (possibly causing variations in inter-eruptive periods), as well as influencing earthquake activity.
In testing the hypothesis, ISVOLC focuses on four volcanoes in Iceland: Katla, Askja, Grímsvötn and Bárðarbunga along with two transform zones: the South Iceland Seismic Zone (SISZ) and Tjörnes Fracture Zone (TFZ), that serve as a natural laboratory for studying the effects of deglaciation on volcanism and seismicity.
ISVOLC activities
ISVOLC coordinates several research activities in a systematic approach to address the scientific topics embedded in the hypothesis. These activities comprise:
- Generating an unprecedented, unified database of volume changes of the Icelandic glaciers since the end of Little Ice Age at high spatial and temporal resolution by using recent work that describes mass change distribution of Icelandic glaciers, based on in situ and remote sensing methods as well as interpretation of aerial observations.
- Creating a new set of three-dimensional (3D) GIA models considering a realistic lithospheric/mantle structure.
- Developing advanced 3D models of magma plumbing beneath key volcanoes, considering magma bodies and magma mush within a magma domain, and episodic melt supply rate.
- Combining the GIA model predictions and the magma plumbing models to produce 3D models that describe effects from both deglaciation and magma influx.
- Generating future scenarios of glacial mass loss for Vatnajökull based on ice dynamic modelling and detailed retreat history for the last 4 decades.
- Determining the effect of both recent and future scenarios of glacier changes on magma generation and supply to, and stability of magma bodies beneath volcanoes.
- Determining the effect of both recent and future scenarios of glacier mass changes on seismic triggering of faults located within two major fault zones in Iceland.
The ISVOLC team: Participating institutions and list of people
- Icelandic Meteorological Office (Michelle Parks, Benedikt G. Ófeigsson, Vincent Drouin, Kristín Vogfjörð, Sara Barsotti)
- Institute of Earth Sciences, University of Iceland (Freysteinn Sigmundsson, Guðfinna Aðalgeirsdóttir, Halldór Geirsson, Finnur Pálson, Eyjólfur Magnússon, Chiara Lanzi, Siqi Li, Yilin Yang, Sonja H. M. Greiner, Catherine Grace O’Hara)
- National Land Survey of Iceland (Joaquin M. M. C. Belart)
- Icelandic Civil Protection, National Commissioner of the Icelandic Police (Björn Oddsson)
- University of Uppsala, Sweden (Peter Schmidt, Rémi Vachon)
- University of Gothenburg, Sweden (Erik Sturkell)
- INGV, National Institute of Geophysics and Volcanology, Italy (Elisa Trasatti)
- ISTerre, France (Fabien Albino)
- GNS Science, New Zealand (Sigrún Hreinsdóttir)
- University of Cambridge, UK (John Maclennan)
- University of Leeds, UK (Andy Hooper, Josefa Sepúlveda)
