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Freysteinn Sigmundsson - Vísindamaður

Freysteinn Sigmundsson

–

Verkfræði- og náttúruvísindasvið

Freysteinn Sigmundsson

Vísindamaður

- Jarðeðlisfræði

Aðsetur
Askja / N-322
Sími
5254491
Tölvupóstur
fs [hjá] hi.is

Starfseining
Jarðvísindastofnun
Vefsíða
http://uni.hi.is/fs

ORCID vefsíða
https://orcid.org/0000-0001-9052-4665
Rannsóknagátt – Freysteinn Sigmundsson

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2025

2023–2024 inflation-deflation cycles at Svartsengi and repeated dike injections and eruptions at the Sundhnúkur crater row, Reykjanes Peninsula, IcelandEarth and Planetary Science Letters
Accessing MagmaEuropean Review
Continuous Subsidence of Dallol Volcano Caused by Magmatic, Hydrothermal, and Salt Dissolution ProcessesGeochemistry, Geophysics, Geosystems
Dyke emplacement and its interaction with fracture systems and regional stress fieldsTectonophysics
Introduction to the Special Issue Geoscience in Active AreasPure and Applied Geophysics
Tectonic Stress as the Driving Mechanism for Dike Opening in an Oblique Rift SettingGeophysical Research Letters
The Influence of Variable Host Rock Cohesion and Magma Viscosity on Intrusion-Fault InteractionJournal of Geophysical Research: Solid Earth

2024

2021–2023 Unrest and Geodetic Observations at Askja Volcano, IcelandGeophysical Research Letters
Fracturing and tectonic stress drive ultrarapid magma flow into dikesScience
Hydraulically linked reservoirs simultaneously fed the 1975–1984 Krafla Fires eruptionsEarth and Planetary Science Letters
Influence of climate change on magmatic processes
Simultaneous rift-scale inflation of a deep crustal sill network in Afar, East AfricaNature Communications
Strain Localization at Volcanoes Undergoing ExtensionGeophysical Research Letters
Volcanic unrest as seen from the magmatic sourceScientific Reports

2023

Constraints on ground deformation processes at the Tulu Moye volcanic complex, Main Ethiopian RiftJournal of Volcanology and Geothermal Research
Correction to: Deformation, seismicity, and monitoring response preceding and during the 2022 Fagradalsfjall eruption, IcelandBulletin of Volcanology
Decades of subsidence followed by rapid upliftJournal of Volcanology and Geothermal Research
Deformation, seismicity, and monitoring response preceding and during the 2022 Fagradalsfjall eruption, IcelandBulletin of Volcanology
Influence of a low viscosity zone on the evolution of post-eruption deformationJournal of Volcanology and Geothermal Research
Interaction between propagating basaltic dikes and pre-existing fracturesJournal of Volcanology and Geothermal Research
Joint Bayesian Modeling of Velocity Break Points, Noise Characteristics, and Their Uncertainties in GNSS Time SeriesGeophysical Research Letters
Looking backward and forwardBulletin of Volcanology
Magma is the Key to Sustainable Super-Hot Geothermal Energy
Pressure increase at the magma-hydrothermal interface at Krafla caldera, North-Iceland, 2018–2020Journal of Volcanology and Geothermal Research

2022

Deformation and seismicity decline before the 2021 Fagradalsfjall eruptionNature
Hybrid Microgravity Monitoring of the Theistareykir Geothermal Reservoir (North Iceland)Pure and Applied Geophysics
Multiple inflation and deflation events from 2004 to 2016 at Fogo (Água de Pau) volcano, São Miguel, AzoresJournal of Volcanology and Geothermal Research
Plate Boundary Deformation and Volcano Unrest at the Azores Triple Junction Determined From Continuous GPS Measurements, 2002–2017Journal of Geophysical Research: Solid Earth
Post-Rifting Relaxation During 2015–2020 Following the Bárðarbunga-Holuhraun Dike Intrusion and Eruption in IcelandGeophysical Research Letters
Quantification of Volcano Deformation Caused by Volatile Accumulation and ReleaseGeophysical Research Letters
Variable inflation rate of a magmatic deformation source beneath Aira caldera after the 1914 eruption of Sakurajima volcanoJournal of Volcanology and Geothermal Research

2021

Assessment of Reservoir Processes Induced by Geothermal Utilization at Reykjanes, SW-Iceland, Inferred from Interferometric Analysis of Satellite Images 2005-2019
Beyond elasticityJournal of Volcanology and Geothermal Research
Eruption risks from covert silicic magma bodiesGeology
Eyjafjallajökull eruption in 2010
Geothermal, Tectonic, and Magmatic Stress Interactions in the Hengill Area, Iceland
Ground Deformation After a Caldera CollapseJournal of Geophysical Research: Solid Earth
Inflation-Deflation Episodes in the Hengill and Hrómundartindur Volcanic Complexes, SW IcelandFrontiers in Earth Science
Special issue on Nordic Remote SensingInternational Journal of Applied Earth Observation and Geoinformation

2020

A half-century of geologic and geothermic investigations in IcelandJournal of Volcanology and Geothermal Research
Deformation due to geothermal exploitation at Reykjanes, IcelandJournal of Volcanology and Geothermal Research
ErratumJournal of Applied Volcanology
Geodynamics of Iceland and the signatures of plate spreadingJournal of Volcanology and Geothermal Research
Influence of hydrothermal alteration on the elastic behaviour and failure of heat-treated andesite from GuadeloupeGeophysical Journal International
Operational response and hazards assessment during the 2014–2015 volcanic crisis at Bárðarbunga volcano and associated eruption at Holuhraun, IcelandJournal of Volcanology and Geothermal Research
Practising an explosive eruption in Iceland: outcomes from a European exerciseJournal of Applied Volcanology
Recent basaltic eruptions in Iceland and the dynamics of co-eruptive subsurface magma flow
The dynamics of a long-lasting effusive eruption modulated by Earth tidesEarth and Planetary Science Letters
Unexpected large eruptions from buoyant magma bodies within viscoelastic crustNature Communications
Viscoelastic crustal response to magma supply and discharge in the upper crustEarth and Planetary Science Letters

2019

Calderas collapse as magma flows into riftsScience
Countrywide Observations of Plate Spreading and Glacial Isostatic Adjustment in Iceland Inferred by Sentinel-1 Radar Interferometry, 2015–2018Geophysical Research Letters
Electrical resistivity tomography and time-domain induced polarization field investigations of geothermal areas at Krafla, IcelandGeophysical Journal International
Ground deformation due to steam cap processes at Reykjanes, SW-IcelandGeophysical Journal International
Icecap and Subglacial Crustal Deformation Inferred From SAR Pixel TrackingJournal of Geophysical Research: Solid Earth
Magma Flow Rates and Temporal Evolution of the 2012–2014 Post-Eruptive Intrusions at El Hierro, Canary IslandsJournal of Geophysical Research: Solid Earth
Tracking Magmatic Hydrogen Sulfur Circulations Using Electrical ImpedanceJournal of Geophysical Research: Solid Earth

2018

Integration of SAR Data Into Monitoring of the 2014–2015 Holuhraun Eruption, IcelandFrontiers in Earth Science
Magma movements in volcanic plumbing systems and their associated ground deformation and seismic patterns
The role of smectites in the electrical conductivity of active hydrothermal systems: electrical properties of core samples from Krafla volcano, IcelandGeophysical Journal International

2017

Deformation at Krafla and Bjarnarflag geothermal areas, Northern Volcanic Zone of Iceland, 1993–2015Journal of Volcanology and Geothermal Research
Deformation in the Northern Volcanic Zone of Iceland 2008–2014Journal of Geophysical Research: Solid Earth
Evolution of deformation and stress changes during the caldera collapse and dyking at Bárdarbunga, 2014–2015Earth and Planetary Science Letters
From magma ascent to ash generationAnnals of Geophysics
Post-emplacement cooling and contraction of lava flowsJournal of Geophysical Research: Solid Earth
Repeated magmatic intrusions at El Hierro Island following the 2011–2012 submarine eruptionJournal of Volcanology and Geothermal Research
Volcano GeodesyJournal of Volcanology and Geothermal Research

2016

Lava field evolution and emplacement dynamics of the 2014-2015 basaltic fissure eruption at Holuhraun, IcelandJournal of Volcanology and Geothermal Research
Constraints on seasonal load variations and regional rigidity from continuous GPS measurements in Iceland, 1997-2014Geophysical Journal International
Continuous subsidence in the Thingvellir rift graben, IcelandJournal of Geophysical Research: Solid Earth
Deep Roots of Geothermal Systems
Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflowScience
New insights into magma plumbing along rift systems from detailed observations of eruptive behavior at Axial volcanoGeophysical Research Letters

2015

Forecasting the path of a laterally propagating dikeJournal of Geophysical Research: Solid Earth
Kilometer-scale Kaiser effect identified in Krafla volcano, IcelandGeophysical Research Letters
Renewability Assessment of the Reykjanes Geothermal System, SW-Iceland
Tectonic and volcanic deformation at São Miguel Island, Azores, observed by continuous GPS analysis 2008-13

2014

Geodetic measurements and numerical models of rifting in northern iceland for 1993-2008Geophysical Journal International
InSAR observations and models of crustal deformation due to a glacial surge in IcelandGeophysical Journal International
Segmented lateral dyke growth in a rifting event at Bárðarbunga volcanic system, IcelandNature
Stress transfer between magma bodiesJournal of Geophysical Research: Solid Earth
Volcanic plume height correlated with magma-pressure change at Grímsvötn Volcano, IcelandNature Geoscience

2013

Ásýnd lands og aldur bergs
ELDUR Í EYJAFJALLAJÖKLI 2010
ELDVIRK SVÆÐI Á ÍSLANDI
EYJAFJALLAJÖKULL
Eyjafjallajökull eruptions 2010
Futurevolc
Geodetic data shed light on ongoing caldera subsidence at Askja, IcelandBulletin of Volcanology
Iceland risingJournal of Geophysical Research: Solid Earth
Innri gerð eldfjalla
Ísland og innri gerð jarðar
New insights into volcanic activity from strain and other deformation data for the Hekla 2000 eruptionJournal of Volcanology and Geothermal Research
Norðurgosbelti

2012

Geophysical constraints on the dynamics of spreading centres from rifting episodes on landNature Geoscience
Multiple Effects of Ice Load Changes and Associated Stress Change on Magmatic Systems
Remote sensing of volcanic hazards and their precursorsProceedings of the IEEE
Subsidence of Askja caldera 2000-2009Journal of Volcanology and Geothermal Research
Volcano deformation at active plate boundariesJournal of Geophysical Research B: Solid Earth

2011

Deep magma storage at Hekla volcano, Iceland, revealed by InSAR time series analysisJournal of Geophysical Research: Solid Earth
Increased capture of magma in the crust promoted by ice-cap retreat in IcelandNature Geoscience
Magma flow directions inferred from field evidence and magnetic fabric studies of the Streitishvarf composite dike in east IcelandJournal of Volcanology and Geothermal Research

2010

Climate effects on volcanismPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
Develop instruments to monitor volcanic ash falloutNature
Influence of surface load variations on eruption likelihoodGeophysical Journal International
Intrusion triggering of the 2010 Eyjafjallajökull explosive eruptionNature
Katla and Eyjafjallajökull Volcanoes
Overview of results from continuous GPS observations in Iceland from 1995 to 2010Jokull
Pressure sources versus surface loadsGeophysical Research Letters
The 2008 May 29 earthquake doublet in SW IcelandGeophysical Journal International

2009

Consequences of local surface load variations for volcano monitoring: Application to Katla subglacial volcano, Iceland
Constraints on magma intrusion at Eyjafjallajökull and Katla volcanoes in Iceland, from time series SAR interferometry
Recent deep-seated magmatic activity and the 2008 M6.3 earthquake
Rheologic controls on inter-rifting deformation of the Northern Volcanic Zone, IcelandEarth and Planetary Science Letters

2008

IcelandEpisodes
Multiple volcano deformation sources in a post-rifting periodJournal of Volcanology and Geothermal Research
Natural hazards in Nordic countriesEpisodes
Nordic geoscience and the 33rd International Geological CongressEpisodes
Seismic and geodetic insights into magma accumulation at Katla subglacial volcano, IcelandJournal of Geophysical Research: Solid Earth
Three-dimensional mechanical models for the June 2000 earthquake sequence in the south Iceland seismic zoneTectonophysics
Will present day glacier retreat increase volcanic activity? Stress induced by recent glacier retreat and its effect on magmatism at the Vatnajökull ice cap, IcelandGeophysical Research Letters

2007

Controlling factors on earthquake swarms associated with magmatic intrusions; Constraints from IcelandJournal of Volcanology and Geothermal Research
Crustal deformation associated with the 1996 Gjálp subglacial eruption, IcelandEarth and Planetary Science Letters
Discriminating volcano deformation due to magma movements and variable surface loadsGeophysical Journal International
Extending the temporal coverage of icelandic crustal deformation measurements through envisat InSAR imagesEuropean Space Agency, (Special Publication) ESA SP
Glacio-isostatic deformation around the Vatnajökull ice cap, Iceland, induced by recent climate warmingJournal of Geophysical Research: Solid Earth

2006

1983-2003 decaying rate of deflation at Askja calderaBulletin of Volcanology
Current plate movements across the Mid-Atlantic ridge determined from 5 years of continuous GPS measurements in IcelandJournal of Geophysical Research: Solid Earth
Deflation of the Askja volcanic systemJournal of Volcanology and Geothermal Research
Deformation studies at Furnas and Sete Cidades Volcanoes (São Miguel Island, Azores). Velocities and further investigationsGeophysical Journal International
Geodynamic signals detected by geodetic methods in Iceland
Iceland Geodynamics, Crustal Deformation and Divergent Plate Tectonics
Icelandic rhythmicsGeophysical Research Letters
Integration of micro-gravity and geodetic data to constrain shallow system mass changes at Krafla Volcano, N IcelandBulletin of Volcanology
Plate tectonicsNature
Probabilistic model for eruptions and associated flood events in the Katla caldera, IcelandComputational Geosciences
Temporal development of the 1999 intrusive episode in the Eyjafjallajökull volcano, Iceland, derived from InSAR imagesBulletin of Volcanology
Volcano geodesy and magma dynamics in IcelandJournal of Volcanology and Geothermal Research

2005

Earthquakes and faults in the Kárahnjúkar area
Earthquakes and faults in the Karahnjukar area - Review of hazards and recommended further studies
Eruption of Grimsvotn volcano, November 1-6, 2004Jokull
Geodetic GPS measurements in south IcelandJournal of Geophysical Research: Solid Earth
Líkindi eldgosa, hlaupa og færslu eldvirkni milli svæða innan Kötluöskjunnar
Net gravity decrease at Askja volcano, IcelandJournal of Volcanology and Geothermal Research
Virkni í Kötlueldstöðinni og nágrenni hennar síðan 1999 og hugsanleg þróun atburðarásar

2004

InSAR based sill model links spatially offset areas of deformation and seismicity for the 1994 unrest episode at Eyjafjallajökull volcano, IcelandGeophysical Research Letters
Regards sur l'Islande, ses déformations vues par interférométrie radar satellitaireDécouverte, Revue du Palais de la découverte
Satellite radar interferometry 1993-1999 suggests deep accumulation of magma near the crust-mantle boundary at the Krafla volcanic system, IcelandGeophysical Research Letters
The 1996 eruption ay Gjálp, Vatnajökull ice cap, IcelandBulletin of Volcanology

2003

Deformation of Grímsvötn volcano, IcelandGeophysical Research Letters
Fault slip distribution of two June 2000 M_W6.5 earthquakes in South Iceland estimated from joint inversion of InSAR and GPS measurementsEarth and Planetary Science Letters
Recent unrest and magma movements at Eyjafjallajökull and Katla volcanoes, IcelandJournal of Geophysical Research: Solid Earth
Triggered fault slip on June 17, 2000 on the Reykjanes Peninsula, SW-Iceland captured by radar interferometryGeophysical Research Letters
Þrýstingur vex undir KötluNáttúrufræðingurinn

2002

Surface effects of faulting and deformation resulting from magma accumulation at the Hengill triple junction, SW Iceland, 1994-1998Journal of Volcanology and Geothermal Research
Three-dimensional glacier surface motion maps at the Gjálp eruption site, Iceland, inferred from combining InSAR and other ice-displacement dataAnnals of Glaciology
Three-dimensional surface motion maps estimated from combined interferometric synthetic aperture radar and GPS dataJournal of Geophysical Research: Solid Earth
Unwrapping ground displacement signals in satellite radar interferograms with aid of GPS data and MRF regularizationIEEE Transactions on Geoscience and Remote Sensing

2001

Coseismic interferograms of two M_s=6.6 earthquakes in the South Iceland Seismic Zone, June 2000Geophysical Research Letters
Crustal deformation at the oblique spreading Reykjanes Peninsula, SW IcelandJournal of Geophysical Research: Solid Earth

2000

CommentEos
Comment on 'volume of magma accumulation or withdrawal estimated from surface uplift or subsidence, with application to the 1960 collapse of Kilauea volcano' by P.T. Delaney and D.F. McTigueBulletin of Volcanology
Continuous deflation of the Askja caldera, Iceland, during the 1983-1998 noneruptive periodJournal of Geophysical Research: Solid Earth
Crustal deformation near Hengill volcano, Iceland 1993-1998European Space Agency, (Special Publication) ESA SP
Crustal deformation near Hengill volcano, Iceland 1993-1998Journal of Geophysical Research: Solid Earth
Remote sensing of volcano deformation by radar interferometry from various satellites

1999

GPS-meßkampagne 1995 zur bestimmung von deformationen der Erdkruste in SüdwestislandZeitschrift fur Vermessungswesen
Low rates of deformation of the Furnas and Fogo Volcanoes, Sao Miguel, Azores, observed with the Global Positioning System, 1993-1997Journal of Volcanology and Geothermal Research
Opening of an eruptive fissure and seaward displacement at Piton de la Fournaise volcano measured by RADARSAT satellite radar interferometryGeophysical Research Letters

1998

Global Positioning System (GPS) monitoring of Santorini volcano
Post-eruptive gravity changes from 1990 to 1996 at Krafla volcano, IcelandJournal of Volcanology and Geothermal Research
Sources of crustal deformation associated with the Krafla, Iceland, eruption of September 1984Geophysical Research Letters

1997

Center of the Iceland hotspot experiences volcanic unrestEos
Crustal deformation from 1992 to 1995 at the mid-atlantic ridge, southwest Iceland, mapped by satellite radar interferometryScience
Extension across a divergent plate boundary, the Eastern Volcanic Rift Zone, south Iceland, 1967-1994, observed with GPS and electronic distance measurementsJournal of Geophysical Research B: Solid Earth
Ice-volcano interaction of the 1996 Gjalp subglacial eruption, Vatnajokull, IcelandNature
Predictions of deformation and gravity change caused by recent melting of the Vatnajokull ice cap, Iceland
Readjustment of the Krafla spreading segment to crustal rifting measured by Satellite Radar InterferometryGeophysical Research Letters
The 1994-1995 seismicity and deformation at the Hengill triple junction, IcelandJournal of Geophysical Research B: Solid Earth

1996

An experiment in glacio-isostasy near Vatnajokull, Iceland, 1991Jokull
Jarðskjálftabeltið á SuðurlandiNáttúrufræðingurinn

1995

GPS measurements at the Furnas volcano: Comparison of L1 and L3 GPS data for volcano monitoring
Plate boundary deformation and continuing deflation of the Askja volcano, North Iceland, determined with GPS, 1987-1993Bulletin of Volcanology
Rift-transform kinematics in south IcelandJournal of Geophysical Research
Slow inflation of the Furnas Volcano, São Miguel, Azores, suggested from initial leveling and global positioning system measurementsGeophysical Research Letters

1994

GPS monitoring of volcanic deformation in Iceland
Strain accumulation 1986–1992 across the Reykjanes Peninsula Plate Boundary, Iceland, determined from GPS measurementsGeophysical Research Letters

1992

Glacio‐isostatic crustal movements caused by historical volume change of the Vatnajökull Ice Cap, IcelandGeophysical Research Letters
Magma chamber deflation recorded by the global positioning systemGeophysical Research Letters
Tectonic implications of the 1989 Afar Earthquake sequenceGeophysical Research Letters

1991

Post‐glacial rebound and asthenosphere viscosity in IcelandGeophysical Research Letters

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