Multiple inflation and deflation events from 2004 to 2016 at Fogo (Água de Pau) volcano, São Miguel, Azores

João D'Araújo; Freysteinn Sigmundsson; Teresa Ferreira; Jun Okada; Maria Lorenzo; Rita Silva; Rita Carmo; João Luís Gaspar

doi:10.1016/j.jvolgeores.2022.107694

Multiple inflation and deflation events from 2004 to 2016 at Fogo (Água de Pau) volcano, São Miguel, Azores

João D'Araújo
, Freysteinn Sigmundsson
, Teresa Ferreira
, Jun Okada
, Maria Lorenzo
, Rita Silva
, Rita Carmo
, João Luís Gaspar

Science Institute

University of Iceland

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

Abstract

Ground deformation at São Miguel Island, Azores, has been mapped with GPS (Global Positioning System) geodetic measurements for understanding volcanic unrest. We use yearly measurements from 52 GPS stations covering the central part of the island, recorded between 2004 and 2016. The results show disturbances in the velocity field, with periods of inflation in 2004–2006 and 2011–2013, and a deflation period in 2013–2016. For each period of deformation, the velocity field is modeled by using sources of pressure change embedded within uniform elastic half-space. Point-pressure, prolate spheroid, and penny-shaped sources are considered. We compare the fits to the data using chi-square statistics and F-tests. The best fit modeled sources are located near the eastern and northeastern rim of Fogo volcano caldera, and to the east of it, at depths in the range of 3.2–3.7 km. Best fit point-pressure source models indicate volume increase in the range of 8.8-10.4×10⁶m³ in 2004–2006, 0.7-5.4×10⁶m³ in 2011–2013, and volume decrease in the range of 3.1-4.4×10⁶m³ in 2013–2016 (95% confidence intervals). The geodetic results, with multiple sources of deformation located in different areas, show that the 2004–2016 activity at São Miguel Island was complex. The location of the 2004–2006 inflation, 3 km northeast of Fogo caldera, and the lack of subsidence reversal can be explained by the permanence of a newly intruded magma body. The location of the 2011–2013 inflation at the eastern rim of Fogo caldera, and the total reversal to subsidence in 2013–2016 can relate to disturbances in a magma chamber under the Fogo caldera or mixed magma-hydrothermal processes.

Original language	English
Article number	107694
Journal	Journal of Volcanology and Geothermal Research
Volume	432
DOIs	https://doi.org/10.1016/j.jvolgeores.2022.107694
Publication status	Published - 1 Dec 2022

Bibliographical note

Funding Information: João D'Araújo is supported by a Ph.D. grant from the Fundo Regional da Ciência e Tecnologia (Regional Government of the Azores) (PROEMPREGO Programme) (M3.1.a/F/134/2015), co-financed by the FEDER FSE program ACORES-10–5369-FSE-000002). We acknowledge the important role of all CIVISA collaborators responsible for the GPS data collection during annual campaign surveys, namely researchers António Trota and Rita Rodrigues, and all external collaborators that helped in the field work. We express our gratitude to all collaborators involved in maintaining and running the CGPS and seismic networks and analyzing the seismic events. We also thank the important contribution from the anonymous reviewers that helped improve the manuscript. The figures in this manuscript were produced using the Generic Mapping Tools (Wessel et al. 2013). Funding Information: João D’Araújo is supported by a Ph.D. grant from the Fundo Regional da Ciência e Tecnologia (Regional Government of the Azores) (PROEMPREGO Programme) ( M3.1.a/F/134/2015 ), co-financed by the FEDER FSE program ACORES-10–5369-FSE-000002 ). We acknowledge the important role of all CIVISA collaborators responsible for the GPS data collection during annual campaign surveys, namely researchers António Trota and Rita Rodrigues, and all external collaborators that helped in the field work. We express our gratitude to all collaborators involved in maintaining and running the CGPS and seismic networks and analyzing the seismic events. We also thank the important contribution from the anonymous reviewers that helped improve the manuscript. The figures in this manuscript were produced using the Generic Mapping Tools ( Wessel et al., 2013 ). Publisher Copyright: © 2022 The Authors

Other keywords

Azores
Crustal deformation
GPS
Volcano unrest

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10.1016/j.jvolgeores.2022.107694

Cite this

@article{38fabd478adc4e55b11e9e93d24f85e9,

title = "Multiple inflation and deflation events from 2004 to 2016 at Fogo ({\'A}gua de Pau) volcano, S{\~a}o Miguel, Azores",

abstract = "Ground deformation at S{\~a}o Miguel Island, Azores, has been mapped with GPS (Global Positioning System) geodetic measurements for understanding volcanic unrest. We use yearly measurements from 52 GPS stations covering the central part of the island, recorded between 2004 and 2016. The results show disturbances in the velocity field, with periods of inflation in 2004–2006 and 2011–2013, and a deflation period in 2013–2016. For each period of deformation, the velocity field is modeled by using sources of pressure change embedded within uniform elastic half-space. Point-pressure, prolate spheroid, and penny-shaped sources are considered. We compare the fits to the data using chi-square statistics and F-tests. The best fit modeled sources are located near the eastern and northeastern rim of Fogo volcano caldera, and to the east of it, at depths in the range of 3.2–3.7 km. Best fit point-pressure source models indicate volume increase in the range of 8.8-10.4×106m3 in 2004–2006, 0.7-5.4×106m3 in 2011–2013, and volume decrease in the range of 3.1-4.4×106m3 in 2013–2016 (95\% confidence intervals). The geodetic results, with multiple sources of deformation located in different areas, show that the 2004–2016 activity at S{\~a}o Miguel Island was complex. The location of the 2004–2006 inflation, 3 km northeast of Fogo caldera, and the lack of subsidence reversal can be explained by the permanence of a newly intruded magma body. The location of the 2011–2013 inflation at the eastern rim of Fogo caldera, and the total reversal to subsidence in 2013–2016 can relate to disturbances in a magma chamber under the Fogo caldera or mixed magma-hydrothermal processes.",

keywords = "Azores, Crustal deformation, GPS, Volcano unrest",

author = "Jo{\~a}o D'Ara{\'u}jo and Freysteinn Sigmundsson and Teresa Ferreira and Jun Okada and Maria Lorenzo and Rita Silva and Rita Carmo and Gaspar, \{Jo{\~a}o Lu{\'i}s\}",

note = "Funding Information: Jo{\~a}o D'Ara{\'u}jo is supported by a Ph.D. grant from the Fundo Regional da Ci{\^e}ncia e Tecnologia (Regional Government of the Azores) (PROEMPREGO Programme) (M3.1.a/F/134/2015), co-financed by the FEDER FSE program ACORES-10–5369-FSE-000002). We acknowledge the important role of all CIVISA collaborators responsible for the GPS data collection during annual campaign surveys, namely researchers Ant{\'o}nio Trota and Rita Rodrigues, and all external collaborators that helped in the field work. We express our gratitude to all collaborators involved in maintaining and running the CGPS and seismic networks and analyzing the seismic events. We also thank the important contribution from the anonymous reviewers that helped improve the manuscript. The figures in this manuscript were produced using the Generic Mapping Tools (Wessel et al. 2013). Funding Information: Jo{\~a}o D{\textquoteright}Ara{\'u}jo is supported by a Ph.D. grant from the Fundo Regional da Ci{\^e}ncia e Tecnologia (Regional Government of the Azores) (PROEMPREGO Programme) ( M3.1.a/F/134/2015 ), co-financed by the FEDER FSE program ACORES-10–5369-FSE-000002 ). We acknowledge the important role of all CIVISA collaborators responsible for the GPS data collection during annual campaign surveys, namely researchers Ant{\'o}nio Trota and Rita Rodrigues, and all external collaborators that helped in the field work. We express our gratitude to all collaborators involved in maintaining and running the CGPS and seismic networks and analyzing the seismic events. We also thank the important contribution from the anonymous reviewers that helped improve the manuscript. The figures in this manuscript were produced using the Generic Mapping Tools ( Wessel et al., 2013 ). Publisher Copyright: {\textcopyright} 2022 The Authors",

year = "2022",

month = dec,

day = "1",

doi = "10.1016/j.jvolgeores.2022.107694",

language = "English",

volume = "432",

journal = "Journal of Volcanology and Geothermal Research",

issn = "0377-0273",

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T1 - Multiple inflation and deflation events from 2004 to 2016 at Fogo (Água de Pau) volcano, São Miguel, Azores

AU - D'Araújo, João

AU - Sigmundsson, Freysteinn

AU - Ferreira, Teresa

AU - Okada, Jun

AU - Lorenzo, Maria

AU - Silva, Rita

AU - Carmo, Rita

AU - Gaspar, João Luís

N1 - Funding Information: João D'Araújo is supported by a Ph.D. grant from the Fundo Regional da Ciência e Tecnologia (Regional Government of the Azores) (PROEMPREGO Programme) (M3.1.a/F/134/2015), co-financed by the FEDER FSE program ACORES-10–5369-FSE-000002). We acknowledge the important role of all CIVISA collaborators responsible for the GPS data collection during annual campaign surveys, namely researchers António Trota and Rita Rodrigues, and all external collaborators that helped in the field work. We express our gratitude to all collaborators involved in maintaining and running the CGPS and seismic networks and analyzing the seismic events. We also thank the important contribution from the anonymous reviewers that helped improve the manuscript. The figures in this manuscript were produced using the Generic Mapping Tools (Wessel et al. 2013). Funding Information: João D’Araújo is supported by a Ph.D. grant from the Fundo Regional da Ciência e Tecnologia (Regional Government of the Azores) (PROEMPREGO Programme) ( M3.1.a/F/134/2015 ), co-financed by the FEDER FSE program ACORES-10–5369-FSE-000002 ). We acknowledge the important role of all CIVISA collaborators responsible for the GPS data collection during annual campaign surveys, namely researchers António Trota and Rita Rodrigues, and all external collaborators that helped in the field work. We express our gratitude to all collaborators involved in maintaining and running the CGPS and seismic networks and analyzing the seismic events. We also thank the important contribution from the anonymous reviewers that helped improve the manuscript. The figures in this manuscript were produced using the Generic Mapping Tools ( Wessel et al., 2013 ). Publisher Copyright: © 2022 The Authors

PY - 2022/12/1

Y1 - 2022/12/1

N2 - Ground deformation at São Miguel Island, Azores, has been mapped with GPS (Global Positioning System) geodetic measurements for understanding volcanic unrest. We use yearly measurements from 52 GPS stations covering the central part of the island, recorded between 2004 and 2016. The results show disturbances in the velocity field, with periods of inflation in 2004–2006 and 2011–2013, and a deflation period in 2013–2016. For each period of deformation, the velocity field is modeled by using sources of pressure change embedded within uniform elastic half-space. Point-pressure, prolate spheroid, and penny-shaped sources are considered. We compare the fits to the data using chi-square statistics and F-tests. The best fit modeled sources are located near the eastern and northeastern rim of Fogo volcano caldera, and to the east of it, at depths in the range of 3.2–3.7 km. Best fit point-pressure source models indicate volume increase in the range of 8.8-10.4×106m3 in 2004–2006, 0.7-5.4×106m3 in 2011–2013, and volume decrease in the range of 3.1-4.4×106m3 in 2013–2016 (95% confidence intervals). The geodetic results, with multiple sources of deformation located in different areas, show that the 2004–2016 activity at São Miguel Island was complex. The location of the 2004–2006 inflation, 3 km northeast of Fogo caldera, and the lack of subsidence reversal can be explained by the permanence of a newly intruded magma body. The location of the 2011–2013 inflation at the eastern rim of Fogo caldera, and the total reversal to subsidence in 2013–2016 can relate to disturbances in a magma chamber under the Fogo caldera or mixed magma-hydrothermal processes.

AB - Ground deformation at São Miguel Island, Azores, has been mapped with GPS (Global Positioning System) geodetic measurements for understanding volcanic unrest. We use yearly measurements from 52 GPS stations covering the central part of the island, recorded between 2004 and 2016. The results show disturbances in the velocity field, with periods of inflation in 2004–2006 and 2011–2013, and a deflation period in 2013–2016. For each period of deformation, the velocity field is modeled by using sources of pressure change embedded within uniform elastic half-space. Point-pressure, prolate spheroid, and penny-shaped sources are considered. We compare the fits to the data using chi-square statistics and F-tests. The best fit modeled sources are located near the eastern and northeastern rim of Fogo volcano caldera, and to the east of it, at depths in the range of 3.2–3.7 km. Best fit point-pressure source models indicate volume increase in the range of 8.8-10.4×106m3 in 2004–2006, 0.7-5.4×106m3 in 2011–2013, and volume decrease in the range of 3.1-4.4×106m3 in 2013–2016 (95% confidence intervals). The geodetic results, with multiple sources of deformation located in different areas, show that the 2004–2016 activity at São Miguel Island was complex. The location of the 2004–2006 inflation, 3 km northeast of Fogo caldera, and the lack of subsidence reversal can be explained by the permanence of a newly intruded magma body. The location of the 2011–2013 inflation at the eastern rim of Fogo caldera, and the total reversal to subsidence in 2013–2016 can relate to disturbances in a magma chamber under the Fogo caldera or mixed magma-hydrothermal processes.

KW - Azores

KW - Crustal deformation

KW - GPS

KW - Volcano unrest

UR - https://www.scopus.com/pages/publications/85140732481

U2 - 10.1016/j.jvolgeores.2022.107694

DO - 10.1016/j.jvolgeores.2022.107694

M3 - Article

SN - 0377-0273

VL - 432

JO - Journal of Volcanology and Geothermal Research

JF - Journal of Volcanology and Geothermal Research

M1 - 107694

ER -

Multiple inflation and deflation events from 2004 to 2016 at Fogo (Água de Pau) volcano, São Miguel, Azores

Abstract

Bibliographical note

Other keywords

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Cite this