Deep long period seismicity preceding and during the 2021 Fagradalsfjall eruption, Iceland

Tim Greenfield; Tom Winder; Nicholas Rawlinson; John Maclennan; Robert S. White; Thorbjörg Ágústsdóttir; Conor A. Bacon; Bryndís Brandsdóttir; Eva P.S. Eibl; Esme Glastonbury-Southern; Egill Árni Gudnason; Gylfi Páll Hersir; Josef Horálek

doi:10.1007/s00445-022-01603-2

Deep long period seismicity preceding and during the 2021 Fagradalsfjall eruption, Iceland

Tim Greenfield^*, Tom Winder, Nicholas Rawlinson, John Maclennan, Robert S. White, Thorbjörg Ágústsdóttir, Conor A. Bacon, Bryndís Brandsdóttir, Eva P.S. Eibl, Esme Glastonbury-Southern, Egill Árni Gudnason, Gylfi Páll Hersir, Josef Horálek

^*Corresponding author for this work

Science Institute

Research output: Contribution to journal › Article › peer-review

Abstract

We use a dense seismic network on the Reykjanes Peninsula, Iceland, to image a group of earthquakes at 10–12 km depth, 2 km north-east of 2021 Fagradalsfjall eruption site. These deep earthquakes have a lower frequency content compared to earthquakes located in the upper, brittle crust and are similar to deep long period (DLP) seismicity observed at other volcanoes in Iceland and around the world. We observed several swarms of DLP earthquakes between the start of the study period (June 2020) and the initiation of the 3-week-long dyke intrusion that preceded the eruption in March 2021. During the eruption, DLP earthquake swarms returned 1 km SW of their original location during periods when the discharge rate or fountaining style of the eruption changed. The DLP seismicity is therefore likely to be linked to the magma plumbing system beneath Fagradalsfjall. However, the DLP seismicity occurred ~ 5 km shallower than where petrological modelling places the near-Moho magma storage region in which the Fagradalsfjall lava was stored. We suggest that the DLP seismicity was triggered by the exsolution of CO₂-rich fluids or the movement of magma at a barrier to the transport of melt in the lower crust. Increased flux through the magma plumbing system during the eruption likely adds to the complexity of the melt migration process, thus causing further DLP seismicity, despite a contemporaneous magma channel to the surface.

Original language	English
Article number	101
Journal	Bulletin of Volcanology
Volume	84
Issue number	12
DOIs	https://doi.org/10.1007/s00445-022-01603-2
Publication status	Published - Dec 2022

Bibliographical note

Funding Information:
We thank all those involved in the deployment of the varying seismic networks used in this study, especially Institute of Earth Sciences, University of Iceland technician Sveinbjörn Steinthórsson without whom such projects would be much more difficult. TG is funded by a Leverhulme Early Career Fellowship (ECF-049), and we also acknowledge funding from the NERC via Urgency Grant NE/W004690/1. The maintenance of REYKJANET, data analysis and interpretation are currently done within the NASPMON project (NAtural Seismicity as a Prospecting and MONitoring tool for geothermal energy extraction). The NASPMON project benefits from a €1 370 000 grant from Iceland, Liechtenstein and Norway through the EEA Grants and the Technology Agency of the Czech Republic within the Kappa Programme. We thank two anonymous reviewers, the handling editor Kristín Jónsdóttir and the editor Andrew Harris for their helpful comments which improved the manuscript. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising. Department of Earth Sciences contribution ESC.6050.

Funding Information:
We thank all those involved in the deployment of the varying seismic networks used in this study, especially Institute of Earth Sciences, University of Iceland technician Sveinbjörn Steinthórsson without whom such projects would be much more difficult. TG is funded by a Leverhulme Early Career Fellowship (ECF-049), and we also acknowledge funding from the NERC via Urgency Grant NE/W004690/1. The maintenance of REYKJANET, data analysis and interpretation are currently done within the NASPMON project (NAtural Seismicity as a Prospecting and MONitoring tool for geothermal energy extraction). The NASPMON project benefits from a €1 370 000 grant from Iceland, Liechtenstein and Norway through the EEA Grants and the Technology Agency of the Czech Republic within the Kappa Programme. We thank two anonymous reviewers, the handling editor Kristín Jónsdóttir and the editor Andrew Harris for their helpful comments which improved the manuscript. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising. Department of Earth Sciences contribution ESC.6050.

Publisher Copyright:
© 2022, The Author(s).

Other keywords

Deep long-period earthquakes
Fagradalsfjall
Iceland
Low-frequency
Magma plumbing system
Reykjanes

Access to Document

10.1007/s00445-022-01603-2

Cite this

Greenfield, T., Winder, T., Rawlinson, N., Maclennan, J., White, R. S., Ágústsdóttir, T., Bacon, C. A., Brandsdóttir, B., Eibl, E. P. S., Glastonbury-Southern, E., Gudnason, E. Á., Hersir, G. P., & Horálek, J. (2022). Deep long period seismicity preceding and during the 2021 Fagradalsfjall eruption, Iceland. Bulletin of Volcanology, 84(12), Article 101. https://doi.org/10.1007/s00445-022-01603-2

@article{cb05b723677c4207a758b5dc796b9fa1,

title = "Deep long period seismicity preceding and during the 2021 Fagradalsfjall eruption, Iceland",

abstract = "We use a dense seismic network on the Reykjanes Peninsula, Iceland, to image a group of earthquakes at 10–12 km depth, 2 km north-east of 2021 Fagradalsfjall eruption site. These deep earthquakes have a lower frequency content compared to earthquakes located in the upper, brittle crust and are similar to deep long period (DLP) seismicity observed at other volcanoes in Iceland and around the world. We observed several swarms of DLP earthquakes between the start of the study period (June 2020) and the initiation of the 3-week-long dyke intrusion that preceded the eruption in March 2021. During the eruption, DLP earthquake swarms returned 1 km SW of their original location during periods when the discharge rate or fountaining style of the eruption changed. The DLP seismicity is therefore likely to be linked to the magma plumbing system beneath Fagradalsfjall. However, the DLP seismicity occurred ~ 5 km shallower than where petrological modelling places the near-Moho magma storage region in which the Fagradalsfjall lava was stored. We suggest that the DLP seismicity was triggered by the exsolution of CO2-rich fluids or the movement of magma at a barrier to the transport of melt in the lower crust. Increased flux through the magma plumbing system during the eruption likely adds to the complexity of the melt migration process, thus causing further DLP seismicity, despite a contemporaneous magma channel to the surface.",

keywords = "Deep long-period earthquakes, Fagradalsfjall, Iceland, Low-frequency, Magma plumbing system, Reykjanes",

author = "Tim Greenfield and Tom Winder and Nicholas Rawlinson and John Maclennan and White, {Robert S.} and Thorbj{\"o}rg {\'A}g{\'u}stsd{\'o}ttir and Bacon, {Conor A.} and Brynd{\'i}s Brandsd{\'o}ttir and Eibl, {Eva P.S.} and Esme Glastonbury-Southern and Gudnason, {Egill {\'A}rni} and Hersir, {Gylfi P{\'a}ll} and Josef Hor{\'a}lek",

note = "Funding Information: We thank all those involved in the deployment of the varying seismic networks used in this study, especially Institute of Earth Sciences, University of Iceland technician Sveinbj{\"o}rn Steinth{\'o}rsson without whom such projects would be much more difficult. TG is funded by a Leverhulme Early Career Fellowship (ECF-049), and we also acknowledge funding from the NERC via Urgency Grant NE/W004690/1. The maintenance of REYKJANET, data analysis and interpretation are currently done within the NASPMON project (NAtural Seismicity as a Prospecting and MONitoring tool for geothermal energy extraction). The NASPMON project benefits from a €1 370 000 grant from Iceland, Liechtenstein and Norway through the EEA Grants and the Technology Agency of the Czech Republic within the Kappa Programme. We thank two anonymous reviewers, the handling editor Krist{\'i}n J{\'o}nsd{\'o}ttir and the editor Andrew Harris for their helpful comments which improved the manuscript. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising. Department of Earth Sciences contribution ESC.6050. Funding Information: We thank all those involved in the deployment of the varying seismic networks used in this study, especially Institute of Earth Sciences, University of Iceland technician Sveinbj{\"o}rn Steinth{\'o}rsson without whom such projects would be much more difficult. TG is funded by a Leverhulme Early Career Fellowship (ECF-049), and we also acknowledge funding from the NERC via Urgency Grant NE/W004690/1. The maintenance of REYKJANET, data analysis and interpretation are currently done within the NASPMON project (NAtural Seismicity as a Prospecting and MONitoring tool for geothermal energy extraction). The NASPMON project benefits from a €1 370 000 grant from Iceland, Liechtenstein and Norway through the EEA Grants and the Technology Agency of the Czech Republic within the Kappa Programme. We thank two anonymous reviewers, the handling editor Krist{\'i}n J{\'o}nsd{\'o}ttir and the editor Andrew Harris for their helpful comments which improved the manuscript. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising. Department of Earth Sciences contribution ESC.6050. Publisher Copyright: {\textcopyright} 2022, The Author(s).",

year = "2022",

month = dec,

doi = "10.1007/s00445-022-01603-2",

language = "English",

volume = "84",

journal = "Bulletin of Volcanology",

issn = "0258-8900",

publisher = "Springer Verlag",

number = "12",

}

Greenfield, T, Winder, T, Rawlinson, N, Maclennan, J, White, RS, Ágústsdóttir, T, Bacon, CA, Brandsdóttir, B, Eibl, EPS, Glastonbury-Southern, E, Gudnason, EÁ, Hersir, GP & Horálek, J 2022, 'Deep long period seismicity preceding and during the 2021 Fagradalsfjall eruption, Iceland', Bulletin of Volcanology, vol. 84, no. 12, 101. https://doi.org/10.1007/s00445-022-01603-2

TY - JOUR

T1 - Deep long period seismicity preceding and during the 2021 Fagradalsfjall eruption, Iceland

AU - Greenfield, Tim

AU - Winder, Tom

AU - Rawlinson, Nicholas

AU - Maclennan, John

AU - White, Robert S.

AU - Ágústsdóttir, Thorbjörg

AU - Bacon, Conor A.

AU - Brandsdóttir, Bryndís

AU - Eibl, Eva P.S.

AU - Glastonbury-Southern, Esme

AU - Gudnason, Egill Árni

AU - Hersir, Gylfi Páll

AU - Horálek, Josef

N1 - Funding Information: We thank all those involved in the deployment of the varying seismic networks used in this study, especially Institute of Earth Sciences, University of Iceland technician Sveinbjörn Steinthórsson without whom such projects would be much more difficult. TG is funded by a Leverhulme Early Career Fellowship (ECF-049), and we also acknowledge funding from the NERC via Urgency Grant NE/W004690/1. The maintenance of REYKJANET, data analysis and interpretation are currently done within the NASPMON project (NAtural Seismicity as a Prospecting and MONitoring tool for geothermal energy extraction). The NASPMON project benefits from a €1 370 000 grant from Iceland, Liechtenstein and Norway through the EEA Grants and the Technology Agency of the Czech Republic within the Kappa Programme. We thank two anonymous reviewers, the handling editor Kristín Jónsdóttir and the editor Andrew Harris for their helpful comments which improved the manuscript. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising. Department of Earth Sciences contribution ESC.6050. Funding Information: We thank all those involved in the deployment of the varying seismic networks used in this study, especially Institute of Earth Sciences, University of Iceland technician Sveinbjörn Steinthórsson without whom such projects would be much more difficult. TG is funded by a Leverhulme Early Career Fellowship (ECF-049), and we also acknowledge funding from the NERC via Urgency Grant NE/W004690/1. The maintenance of REYKJANET, data analysis and interpretation are currently done within the NASPMON project (NAtural Seismicity as a Prospecting and MONitoring tool for geothermal energy extraction). The NASPMON project benefits from a €1 370 000 grant from Iceland, Liechtenstein and Norway through the EEA Grants and the Technology Agency of the Czech Republic within the Kappa Programme. We thank two anonymous reviewers, the handling editor Kristín Jónsdóttir and the editor Andrew Harris for their helpful comments which improved the manuscript. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising. Department of Earth Sciences contribution ESC.6050. Publisher Copyright: © 2022, The Author(s).

PY - 2022/12

Y1 - 2022/12

N2 - We use a dense seismic network on the Reykjanes Peninsula, Iceland, to image a group of earthquakes at 10–12 km depth, 2 km north-east of 2021 Fagradalsfjall eruption site. These deep earthquakes have a lower frequency content compared to earthquakes located in the upper, brittle crust and are similar to deep long period (DLP) seismicity observed at other volcanoes in Iceland and around the world. We observed several swarms of DLP earthquakes between the start of the study period (June 2020) and the initiation of the 3-week-long dyke intrusion that preceded the eruption in March 2021. During the eruption, DLP earthquake swarms returned 1 km SW of their original location during periods when the discharge rate or fountaining style of the eruption changed. The DLP seismicity is therefore likely to be linked to the magma plumbing system beneath Fagradalsfjall. However, the DLP seismicity occurred ~ 5 km shallower than where petrological modelling places the near-Moho magma storage region in which the Fagradalsfjall lava was stored. We suggest that the DLP seismicity was triggered by the exsolution of CO2-rich fluids or the movement of magma at a barrier to the transport of melt in the lower crust. Increased flux through the magma plumbing system during the eruption likely adds to the complexity of the melt migration process, thus causing further DLP seismicity, despite a contemporaneous magma channel to the surface.

AB - We use a dense seismic network on the Reykjanes Peninsula, Iceland, to image a group of earthquakes at 10–12 km depth, 2 km north-east of 2021 Fagradalsfjall eruption site. These deep earthquakes have a lower frequency content compared to earthquakes located in the upper, brittle crust and are similar to deep long period (DLP) seismicity observed at other volcanoes in Iceland and around the world. We observed several swarms of DLP earthquakes between the start of the study period (June 2020) and the initiation of the 3-week-long dyke intrusion that preceded the eruption in March 2021. During the eruption, DLP earthquake swarms returned 1 km SW of their original location during periods when the discharge rate or fountaining style of the eruption changed. The DLP seismicity is therefore likely to be linked to the magma plumbing system beneath Fagradalsfjall. However, the DLP seismicity occurred ~ 5 km shallower than where petrological modelling places the near-Moho magma storage region in which the Fagradalsfjall lava was stored. We suggest that the DLP seismicity was triggered by the exsolution of CO2-rich fluids or the movement of magma at a barrier to the transport of melt in the lower crust. Increased flux through the magma plumbing system during the eruption likely adds to the complexity of the melt migration process, thus causing further DLP seismicity, despite a contemporaneous magma channel to the surface.

KW - Deep long-period earthquakes

KW - Fagradalsfjall

KW - Iceland

KW - Low-frequency

KW - Magma plumbing system

KW - Reykjanes

UR - http://www.scopus.com/inward/record.url?scp=85141173147&partnerID=8YFLogxK

U2 - 10.1007/s00445-022-01603-2

DO - 10.1007/s00445-022-01603-2

M3 - Article

AN - SCOPUS:85141173147

SN - 0258-8900

VL - 84

JO - Bulletin of Volcanology

JF - Bulletin of Volcanology

IS - 12

M1 - 101

ER -

Deep long period seismicity preceding and during the 2021 Fagradalsfjall eruption, Iceland

Abstract

Bibliographical note

Other keywords

Access to Document

Fingerprint

Cite this