Sigurjón Jónsson

King Abdullah University of Science and Technology

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Yann Klinger

Institut de physique du globe de Paris

P. Martín

King Abdullah University of Science and Technology

Hannes Vasyura‐Bathke

Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences

J. Ruch

University of Geneva

J. Woessner

GeoModelling Solutions (Switzerland)

Guangcai Feng

Central South University

Wenbin Xu

Central South University

Shimon Wdowinski

Florida International University

Alain Bonneville

Pacific Northwest National Laboratory

Giorgio Spada

University of Bologna

Cooperative Institutions

John Wiley & Sons (United States)

Centre National de la Recherche Scientifique

Hanover College

University of Iceland

King Abdullah University of Science and Technology

Icelandic Meteorological Office

Institut de Recherche pour le Développement

Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences

Planetary Science Institute

United States Geological Survey

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Two recent surtseyan eruptions in the Zubair archipelago (Red Sea) studied using high-resolution radar and optical satellite remote sensing

EGUGA (2014)

Wenbin Xu Sigurjón Jónsson

Archipelago

Source

Cite

Citations (1)

Simultaneous Bayesian Estimation of Non‐Planar Fault Geometry and Spatially‐Variable Slip

Journal of Geophysical Research Solid Earth (2021)

Rishabh Dutta Sigurjón Jónsson Hannes Vasyura‐Bathke

Abstract Large earthquakes are usually modeled with simple planar fault surfaces or a combination of several planar fault segments. However, in general, earthquakes occur on faults that are non‐planar and exhibit significant geometrical variations in both the along‐strike and down‐dip directions at all spatial scales. Mapping of surface fault ruptures and high‐resolution geodetic observations are increasingly revealing complex fault geometries near the surface and accurate locations of aftershocks often indicate geometrical complexities at depth. With better geodetic data and observations of fault ruptures, more details of complex fault geometries can be estimated resulting in more realistic fault models of large earthquakes. To address this topic, we here parametrize non‐planar fault geometries with a set of polynomial parameters that allow for both along‐strike and down‐dip variations in the fault geometry. Our methodology uses Bayesian inference to estimate the non‐planar fault parameters from geodetic data, yielding an ensemble of plausible models that characterize the uncertainties of the non‐planar fault geometry and the fault slip. The method is demonstrated using synthetic tests considering slip spatially distributed on a single continuous finite non‐planar fault surface with varying dip and strike angles both in the down‐dip and along‐strike directions. The results show that fault‐slip estimations can be biased when a simple planar fault geometry is assumed in presence of significant non‐planar geometrical variations. Our method can help to model earthquake fault sources in a more realistic way and may be extended to include multiple non‐planar fault segments or other geometrical fault complexities.

Fault model

10.1029/2020jb020441

Cite

Citations (24)

Birth of two volcanic islands in the southern Red Sea

Nature Communications (2015)

Wenbin Xu J. Ruch Sigurjón Jónsson

Abstract Submarine eruptions that lead to the formation of new volcanic islands are rare and far from being fully understood; only a few such eruptions have been witnessed since Surtsey Island emerged to the south of Iceland in the 1960s. Here we report on two new volcanic islands that were formed in the Zubair archipelago of the southern Red Sea in 2011–2013. Using high-resolution optical satellite images, we find that the new islands grew rapidly during their initial eruptive phases and that coastal erosion significantly modified their shapes within months. Satellite radar data indicate that two north–south-oriented dykes, much longer than the small islands might suggest, fed the eruptions. These events occurred contemporaneously with several local earthquake swarms of the type that typically accompany magma intrusions. Earthquake activity has been affecting the southern Red Sea for decades, suggesting the presence of a magmatically active zone that has previously escaped notice.

Archipelago

Submarine volcano

10.1038/ncomms8104

Cite

Citations (47)

Issue Information

Journal of Geophysical Research Solid Earth (2014)

Brooks Hanson Victoria Forlini Max Moorkamp M. R. Nedimović S. W. Parman

10.1002/jgrb.50328

Cite

Citations (0)

Influence of ring faulting in localizing surface deformation at subsiding calderas

Earth and Planetary Science Letters (2019)

Yuan‐Kai Liu J. Ruch Hannes Vasyura‐Bathke Sigurjón Jónsson

Caldera

Magma chamber

Sill

Unrest

10.1016/j.epsl.2019.115784

Cite

Citations (28)

Seismicity Associated With the Formation of a New Island in the Southern Red Sea

Frontiers in Earth Science (2018)

Jade H. W. Eyles Finnigan Illsley‐Kemp Derek Keir J. Ruch Sigurjón Jónsson

Volcanic eruptions at mid-ocean ridges are rarely witnessed due to their inaccessibility, and are therefore poorly understood. Shallow waters in the Red Sea allow the study of ocean ridge related volcanism observed close to sea level. On the 18th December 2011, Yemeni fishermen witnessed a volcanic eruption in the southern Red Sea that led to the formation of Sholan Island. Previous research efforts to constrain the dynamics of the intrusion and subsequent eruption relied primarily on GPS and InSAR methods, data for which was relatively sparse. Our study integrates InSAR analysis with seismic data from Eritrea, Yemen and Saudi Arabia to provide additional insights into the transport of magma in the crust that fed the eruption. Twenty-three earthquakes of magnitude 2.1 to 3.9 were located using the Oct-tree sampling algorithm. The earthquakes propagated southeastward from north of Sholan Island, mainly between December 12th and December 13th. The seismicity is interpreted as being induced by emplacement of a ~12 km-long dike. Earthquake focal mechanisms are primarily normal faulting and suggest the seismicity was caused through a combination of dike propagation and inflation. We combine these observations with new deformation modeling to constrain the location and orientation of the dike. The best-fit dike orientation that satisfies both geodetic and seismic data is NNW-SSE, parallel to the overall strike of the Red Sea. Further, the timing of the seismicity suggests the volcanic activity began as a submarine eruption on the 13th December. The new intrusion and eruption along the ridge suggests seafloor spreading is active in this region.

Dike

Vulcanian eruption

10.3389/feart.2018.00141

Cite

Citations (19)

Changes in groundwater trace element concentrations before seismic and volcanic activities in Iceland during 2010–2018

The Science of The Total Environment (2021)

Maurizio Barbieri Stefania Franchini Marino Domenico Barberio Andrea Billi Tiziano Boschetti

We analysed temporal variations of trace element concentrations in groundwater from a 101 m-deep borehole (HA01) in northern Iceland during 2010–2018 and compared them with seismic and volcanic events that occurred in the same period to identify potential hydrogeochemical precursors. An increase of B, Al, V, Li and Mo concentrations started from eight months to one month before the 2014 Bárðarbunga eruption (~115 km from HA01), a major rifting event in central Iceland, while Ga and V concentrations began to increase one day and one month after the onset of the event, respectively. We also found that concentrations of some trace elements (Li, B, Ga, Mo, Sr, Rb and Fe) significantly increased before an Mw 5.0 earthquake that occurred ~80 km from the borehole in 2018. However, other notable hydrogeochemical changes were detected during the monitoring period without apparent correlation with the seismic and volcanic events in the region. This study shows that the systematic long-term hydrogeochemical monitoring in seismic and volcanic areas is critical to advance the science of seismic and eruptive precursors. Furthermore, the use of statistical tools, such as Principal Component Analysis (PCA) and Change Point (CP) detection can help identify the most useful chemical elements and validate the trend variability of those elements in the time series, reducing arbitrary choices of pre-seismic and pre-volcanic hydrogeochemical anomalies as potential precursors.

Trace element

Volcanic ash

10.1016/j.scitotenv.2021.148635

Cite

Citations (40)

Bayesian estimation of source parameters and associated Coulomb failure stress changes for the 2005 Fukuoka (Japan) Earthquake

Geophysical Journal International (2017)

Rishabh Dutta Sigurjón Jónsson Teng Wang Hannes Vasyura‐Bathke

Several researchers have studied the source parameters of the 2005 Fukuoka (northwestern Kyushu Island, Japan) earthquake (Mw 6.6) using teleseismic, strong motion and geodetic data. However, in all previous studies, errors of the estimated fault solutions have been neglected, making it impossible to assess the reliability of the reported solutions. We use Bayesian inference to estimate the location, geometry and slip parameters of the fault and their uncertainties using Interferometric Synthetic Aperture Radar and Global Positioning System data. The offshore location of the earthquake makes the fault parameter estimation challenging, with geodetic data coverage mostly to the southeast of the earthquake. To constrain the fault parameters, we use a priori constraints on the magnitude of the earthquake and the location of the fault with respect to the aftershock distribution and find that the estimated fault slip ranges from 1.5 to 2.5 m with decreasing probability. The marginal distributions of the source parameters show that the location of the western end of the fault is poorly constrained by the data whereas that of the eastern end, located closer to the shore, is better resolved. We propagate the uncertainties of the fault model and calculate the variability of Coulomb failure stress changes for the nearby Kego fault, located directly below Fukuoka city, showing that the main shock increased stress on the fault and brought it closer to failure.

10.1093/gji/ggx551

Cite

Citations (9)

Rapid Inflation Followed by Trapdoor Faulting in April 2005, Measured by Continuous GPS and InSAR at Sierra Negra Volcano, Galapagos

AGUFM (2005)

D. Geist D. Johnson W. W. Chadwick Sigurjón Jónsson M. P. Poland

Source

Cite

Citations (0)

Source model for the 1997 Zirkuh earthquake (MW= 7.2) in Iran derived from JERS and ERS InSAR observations

Geophysical Journal International (2011)

Henriette Sudhaus Sigurjón Jónsson

We present the first detailed source model of the 1997 M7.2 Zirkuh earthquake that ruptured the entire Abiz fault in East Iran producing a 125 km long, bended and segmented fault trace. Using SAR data from the ERS and JERS-1 satellites we first determined a multisegment fault model for this predominately strike-slip earthquake by estimating fault-segment dip, slip, and rake values using an evolutionary optimization algorithm. We then inverted the InSAR data for variable slip and rake in more detail along the multisegment fault plane. We complement our optimization with importance sampling of the model parameter space to ensure that the derived optimum model has a high likelihood, to detect correlations or trade-offs between model parameters, and to image the model resolution. Our results are in an agreement with field observations showing that this predominantly strike-slip earthquake had a clear change in style of faulting along its rupture. In the north we find that thrust faulting on a westerly dipping fault is accompanied with the strike-slip that changes to thrust faulting on an eastward dipping fault plane in the south. The centre part of the fault is vertical and has almost pure dextral strike-slip. The heterogeneous fault slip distribution shows two regions of low slip near significant fault step-overs of the Abiz fault and therefore these fault complexities appear to reduce the fault slip. Furthermore, shallow fault slip is generally reduced with respect to slip at depth. This shallow slip deficit varies along the Zirkuh fault from a small deficit in the North to a much larger deficit along the central part of the fault, a variation that is possibly related to different interseismic repose times.

Thrust fault

Fault trace

Rake

Fault model

10.1111/j.1365-246x.2011.04973.x

Cite

Citations (49)