1. Processes generating seismic signals on glacier-covered volcanoes
One of the problems associated with monitoring of volcanoes that are partly covered by glaciers is the separation of signals associated with movements of the glacier from those generated by volcanic processes. Several active Icelandic volcanoes have substantial glaciers that are known to produce seismic signals. This is particularly critical for volcanoes like Katla and Öræfajökull that constitute a significant threat to human habitation. Steep valley glaciers exist on both volcanoes that are known to produce audible sound. It is proposed to operate sound recording systems, cameras, and additional seismographs around these glaciers for limited times during the summer in order to identify ice collapse events. The seismic signals from these events will then be identified on the permanent, regional seismograph system, and their seismological characteristics determined. The project involves considerable field work and requires some signal analysis skills. The project is run in cooperation with Prof. Ólafur Guðmundsson at the University of Uppsala.
Main NordVulk collaborator: Professor Páll Einarsson, Institute of Earth Sciences, University of Iceland.
Nordic collaborator: Professor Ólafur Guðmundsson, Department of Earth Sciences, Uppsala University, Sweden.
For more information please contact: palli@hi.is
2. Where does the magma crystallize beneath Hekla volcano?
Most eruptions at Hekla produce basaltic icelandite at the end of each eruption. The magma is poor in minerals but plagioclase, clinopyroxene, olivine and FeTi-oxide have been identified. Clinopyroxene and melt compositions record equilibrium crystallization temperature and pressure, whereas those of plagioclase are also dependent on water concentrations and the oxide composition may record both temperature and oxygen fugacity. In this project, tephra from Hekla will be collected in order to determine the invariant parameters of crystallization. The results should reveal the depth of magma reservoir beneath Hekla and aid interpretations of real-time geophysical data.
Main NordVulk collaborator: Olgeir Sigmarsson, Institute of Earth Sciences, University of Iceland.
Potential Nordic collaborator: NordSim facility, Sweden
For more information please contact: olgeir@hi.is
3. Tephra stratigraphy in Svalbard and Greenland – Distal deposition of Icelandic tephra
The aim of the project is to investigate distal deposition of Icelandic tephra in the high-Arctic by constructing a tephra stratigraphical framework using a large collection of Holocene lake sediments from Svalbard and Greenland. Information on distal distribution of Icelandic tephra in the high-Arctic is sparse. Therefore, a tephra stratigraphical framework from Svalbard and Greenland will be an important contribution to the knowledge on explosive volcanism in the North Atlantic region and will provide a more comprehensive record on tephra distribution extent and pathways. Tephra investigation in the lake sediments from Svalbard and Greenland has the potential to answer questions such as:
• Which volcanoes/volcanic provenances were the key players in tephra deposition on Svalbard and Greenland during the Holocene?
• How frequent was the tephra deposition?
• Is there evidence of volcanism/tephra from other volcanic provenances than Iceland, such as the Aleutian arch or Kamchatka?
Information on distal distribution of tephra is important for understanding explosive volcanic processes, events and behavior of volcanoes as well as being of significant value for volcanic risk assessment and hazard modeling.
Furthermore, such a tephra stratigraphical study has the potential to provide a chronological framework for paleoclimatological archives in the Arctic.
Main Nordvulk collaborators: Esther Ruth Guðmundsdóttir, Bergrún Arna Óladóttir and Ólafur Ingólfsson, Institute of Earth Sciences, University of Iceland.
Nordic collaborator: Anders Schomacker, University of Tromsö, Norway
For more information please contact: estherrg@hi.is
4. Timing of early Holocene explosive eruptions in Iceland – improved tephrochronology
The aim of the project is to establish a more robust Icelandic tephrochronology by increasing the number of securely dated early Holocene tephra marker horizons. The focus will be on radiocarbon dating tephra layers/eruptions between the Hekla 5 and Saksunarvatn tephras in soil profiles and peatlands in Iceland. The existing dates on tephra layers from this time period have been retrieved by indirect dating, interpolating with SAR (soil/sediment accumulation rate) between tephras of known age. Thus, it is critically important to establish securely dated tephra markers within this period, which represents about one third of the Holocene. A detailed tephra stratigraphy from Lake Lögurinn, East Iceland, comprises several early Holocene tephra layers (Gudmundsdóttir et al., 2016) that will be targeted for radiocarbon dating in peatlands and soil sections in East, Northeast and North Iceland.
By establishing a robust tephrochronology for the early Holocene, Icelandic tephrochronological framework will become more precise and reliable for dating and correlation purposes. As an example, this could significantly aid and improve the chronological status of deglacial landforms and increase our understanding of early Holocene mass-wasting in these parts of Iceland. Moreover, timing of early Holocene explosive eruptions will be significantly improved and information on eruption frequency patterns will be better constrained.
Main Nordvulk collaborators: Esther Ruth Guðmundsdóttir, Bergrún Arna Óladóttir, Hreggviður Norðdahl and Ívar Örn Benediktsson, Institute of Earth Sciences, University of Iceland.
Nordic collaborator: Jesper Olsen, University of Aarhus, Denmark
For more information please contact: estherrg@hi.is
5. Magma-tectonics of a developing rift system: crustal deformation in Iceland’s Eastern Volcanic Zone
The Eastern Volcanic Zone (EVZ) is Iceland's most active volcanic region by eruptive volume and marks the main plate boundary rift in the southern part of Iceland. The crustal deformation in the area is dominated by the Eurasia - North-America plate motion, however, it is complicated by regional signals from glacio-isostatic rebound (GIA), co- and post seismic deformation, volcanic events (such as intrusion-eruption events in the Bárðarbunga volcanic system) and division of the plate spreading between different segments of the plate boundary (e.g., the Western Volcanic Zone).
This project will employ a wealth of new geodetic data (GPS and InSAR) and modeling to study the Eastern Volcanic Zone in detail, addressing research questions such as: How does crust and mantle rheology at the plate boundary influence the plate spreading process? Where is the spreading axis of the EVZ located within its ~70 km wide area; what part of the plate boundary is most likely to fail in the next rifting episode: what is the role of GIA in the area for modulating volcanism in the EVZ; are there temporal changes in deformation at specific volcanoes or other substructures of the EVZ?
Main Nordvulk collaborators: Halldór Geirsson and Freysteinn Sigmundsson, Institute of Earth Sciences, University of Iceland.
For more information please contact: hgeirs@hi.is
6. Petrogenesis of the Trölladyngja lava shield
The Trölladyngja lava shield represents one of Iceland’s most spectacular shield formations. With an estimated volume of about 15 km3, it is comparable to the well-studied, large-volume fissure eruptions, such as the historical Laki and Eldgjá lava flows. However, preliminary datasets available at Nordvulk suggest that, in contrast to these recent events, the Trölladyngja eruption products reveal significant chemical heterogeneity, which straddles the primitive spectrum of Icelandic basalts. The principal aim of this project is to unravel the magma plumbing system of the Trölladyngja lava shield through a systematic study involving (i) fluid and melt inclusions, (ii) mineralogical data (e.g., cpx geobarometry) to constrain depth of magma equilibration and timescales associated with ascent from possible deep-crustal reservoirs. A key observation in this regard is the fact that, unlike most large-volume fissure eruptions, phenocryst (ol, plag and cpx) content is significant, opening up the exciting prospect of better constraining where Icelandic magmas reside and evolve between source and surface. Additionally, the degree of heterogeneity among the mantle sources of Trölladyngja will be assessed by means of radiogenic isotopes.
NordVulk is already in possession of an extensive set of samples from Trölladyngja, and with analytical equipment that includes a new electron microprobe, MC-ICP-MS, FTIR instrument and stages for high- and low-temperature thermometry. This project has the potential of developing into a full PhD research project focused on the petrogenesis of basaltic magmas near the center of the Iceland mantle plume. It may also be well suited for one-year post-doctoral researcher.
Main NordVulk collaborator: Sæmundur Ari Halldórsson, Institute of Earth Sciences, University of Iceland. Further potential collaborators: Enikő Bali, Guðmundur Guðfinnsson, and Þorvaldur Þórðarson, Institute of Earth Sciences, University of Iceland
For more information, please contact: saemiah@hi.is
7. Origin of flank zone magmas in Iceland: the case of Esjufjöll and Snæfell, eastern Iceland
The initial aim of this project is centered on the petrogensis of magmas from two volcanoes, Esjufjöll and Snæfell, which are part of the Öræfajökull flank zone, and are, to a large extent covered by Iceland’s largest glacier, Vatnajökull. Preliminary dataset available at Nordvulk have shown that these two volcanoes have generated a continuous spectrum of igneous rocks, ranging from primitive basalts to rhyolites. However, the core of this project involves the use of radiogenic (Sr-Nd-Hf-Pb) and stable isotopes (e.g., oxygen) to assess petrogenetic processes responsible for generating a full spectrum of magmas, at significant distance from the active spreading axis in Iceland.
This project has the potential of developing into a full PhD research project centered on the petrogenesis of flank zone magmas in eastern Iceland.
Main NordVulk collaborator: Sæmundur Ari Halldórsson, Institute of Earth Sciences, University of Iceland.
Potential Nordic collaborator: Reidar Trønnes, University of Oslo, Norway.
For more information, please contact: saemiah@hi.is
8. Petrogenesis and volatile origin at the Kverkfjöll volcanic system
The late Quaternary subglacial volcanic system of Kverkfjöll, located on the east margin of the Northern rift zone, is characterized by a dense volcanic fissure swarm that is situated adjacent to the Iceland mantle plume. Preliminary geochemical datasets available at Nordvulk, in addition to rather limited set of published data, suggest that volcanic rocks of this region are dominated by homogeneous Fe-rich basalts with rather high abundances of incompatible elements relative to rift-zone tholeiitic basalts from elsewhere in Iceland. This enriched geochemical character of Kverkfjöll basalts is particularly notable in the case of volatile elements, for example the halogens. The principal aim of this project is to unravel the origin of this enriched character of the Kverkfjöll rocks by means of a systematic study involving (i) whole rock lava samples, (ii) hyaloclastite glasses, (iii) fluid and melt inclusions in magmatic crystals and (iv) geothermal fluids.
NordVulk is already in possession of an extensive set of rock samples from Kverkfjöll and preliminary geochemical datasets, in addition to data on fluid geochemistry, will be made available to the research fellow. In-house analytical equipment relevant for this project includes a new electron microprobe, MC-ICP-MS, ICP-OES and an extraction line for S-isotopes. This project has the potential of developing into a full PhD research project focused on elucidating volatile origin in vicinity of the Iceland mantle plume.
Main NordVulk collaborator: Sæmundur Ari Halldórsson, Institute of Earth Sciences, University of Iceland. Further potential collaborators: Enikö Bali and Andri Stefánsson, Institute of Earth Sciences, University of Iceland.
Potential Nordic collaborator Vesa Nykänen, Geological Survey of Finland.
For more information, please contact: saemiah@hi.is
9. Ice- volcano interactions in Jan Mayen
The project aims at understand the interaction between volcanism and glacial ice in Jan Mayen for the past 200 ka. Jan Mayen is the northern most volcanic island in the north Atlantic. Glacial ice extend through the past 200 Ka on the island is poorly understood. Aim of the project is to map and categorize the extend and timing of magmatic interaction with glacier ice on Jan Mayen. At present the main volcano Beerenberg is covered with a small Ice cap that does affect its eruptions. Its dynamic interplay will be studied and the extend of volcanic formations formed during the past 200 Ka. Project is doctoral and a collaborative study between University of Iceland and the Norwegian geological survey.
Main NordVulk collaborator: Ármann Höskuldsson, Institute of Earth Sciences, University of Iceland.
Nordic collaborator: Norweigian Geological Survey.
For more information, please contact: armh@hi.is
10. Petrography and geochemistry of hydrothermally altered drill cores from Hoffell, Southeast Iceland
Southeast Iceland has experienced more erosion than other parts of Iceland, leading to exposures of volcanic rocks and intrusions from greater depths than elsewhere in the country. Hoffell is in this area near the edge of Vatnajökull glacier, where erosion has removed over 2000 meters of overburden and exposed highly altered rocks in the lower greenschist facies at the flanks of Geitafell central volcano. A number of background studies are available from the field, several PhD and MSc studies, and most recently a mineralogical study within the EU-FP7 supported IMAGE project. As a part of an exploration effort to find hot water for domestic use, a number of wells have been drilled in the vicinity of Hoffell farmhouse, including two where 102 m and 140 m of drill cores were recovered. The cores are exceptionally continuous, but have not been properly studied. They show well developed structural and mineralogical features, including secondary mineral assemblages of greenschist facies alteration, and possibly some contact metamorphism, and superimposition of zeolite facies mineralogy. The successful applicant is expected to perform a detailed petrographic study of the cores and do some geochemical analyses, an appealing and challenging study for an interested researcher. In addition to facilities provided at the University of Iceland, the applicant will have access to the drill core research lab at the Reykjanes geothermal power plant. This study is especially timely in light of the recent successful drilling of a 4.65 km deep geothermal well into amphibolite grade rocks at Reykjanes by the IDDP consortium.
Main NordVulk collaborators: Enikő Bali and Guðmundur H. Guðfinnsson, Institute of Earth Sciences, University of Iceland.
Nordic collaborators: Guðmundur Ómar Friðleifsson at HS Orka, and Magnús Ólafsson at Iceland GeoSurvey.
For more information, please contact: gudmhg@hi.is