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Goldman RT, Albright JA, Gravley DM, Grosfils EB, Gregg PM, Hampton SJ. Stress Control of Dike Deflection and Flank Eruption at Akaroa Volcano, New Zealand. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH 2022; 127:e2022JB024305. [PMID: 36250160 PMCID: PMC9539607 DOI: 10.1029/2022jb024305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 07/25/2022] [Accepted: 08/02/2022] [Indexed: 06/16/2023]
Abstract
Understanding the stress evolution of extinct volcanoes can improve efforts to forecast flank eruptions on active systems. Field, petrographic, and seismic data are combined with numerical modeling to investigate the paleo-stress field of New Zealand's Akaroa Volcano, or Akaroa Volcanic Complex. Field mapping identifies 86 radially oriented dikes and seven lava domes found only within a narrow elevation range along Akaroa's erosional crater rim. These observations suggest that crater rim dike emplacement resulted from lateral deflection of vertically ascending intrusions from a centralized magma source, which in turn may have facilitated formation of the lava domes, as well as two scoria cones. We postulate that dike deflection occurred along a stress barrier, as neither a compositional change nor structural boundary are present. We use a finite element model (FEM) simulating Akaroa to test how different factors may have influenced the system's stress state and dike geometry. Elastic, non-flexural ("roller") model configurations containing a large, oblate, and shallow magma chamber produce stress barriers most conducive to radial dike emplacement along Akaroa's crater rim. These configurations also simulate rapid edifice construction above a preexisting lithospheric "bulge." Conversely, simulating flexural stresses exerted on the lithosphere by Akaroa's large mass hinder rather than promote radial dike emplacement. Temperature-dependent viscoelastic relaxation promotes gradual increases in stress barrier elevation, though this effect is strongly dependent on magma chamber parameters. These results suggest that Akaroa was constructed rapidly (within ∼100 kyr) prior to crater rim dike emplacement, which occurred throughout the volcano's remaining active lifespan.
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Affiliation(s)
- Robert T. Goldman
- Department of GeologyUniversity of Illinois at Urbana‐ChampaignUrbanaILUSA
| | - John A. Albright
- Department of GeologyUniversity of Illinois at Urbana‐ChampaignUrbanaILUSA
| | - Darren M. Gravley
- School of Earth and EnvironmentUniversity of CanterburyChristchurchNew Zealand
| | | | - Patricia M. Gregg
- Department of GeologyUniversity of Illinois at Urbana‐ChampaignUrbanaILUSA
| | - Samuel J. Hampton
- School of Earth and EnvironmentUniversity of CanterburyChristchurchNew Zealand
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Thiele ST, Cruden AR, Micklethwaite S, Bunger AP, Köpping J. Dyke apertures record stress accumulation during sustained volcanism. Sci Rep 2020; 10:17335. [PMID: 33060760 PMCID: PMC7566645 DOI: 10.1038/s41598-020-74361-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 09/02/2020] [Indexed: 11/24/2022] Open
Abstract
The feedback between dyke and sill intrusions and the evolution of stresses within volcanic systems is poorly understood, despite its importance for magma transport and volcano instability. Long-lived ocean island volcanoes are crosscut by thousands of dykes, which must be accommodated through a combination of flank slip and visco-elastic deformation. Flank slip is dominant in some volcanoes (e.g., Kilauea), but how intrusions are accommodated in other volcanic systems remains unknown. Here we apply digital mapping techniques to collect > 400,000 orientation and aperture measurements from 519 sheet intrusions within Volcán Taburiente (La Palma, Canary Islands, Spain) and investigate their emplacement and accommodation. We show that vertically ascending dykes were deflected to propagate laterally as they approached the surface of the volcano, forming a radial dyke swarm, and propose a visco-elastic model for their accommodation. Our model reproduces the measured dyke-aperture distribution and predicts that stress accumulates within densely intruded regions of the volcano, blocking subsequent dykes and causing eruptive activity to migrate. These results have significant implications for the organisation of magma transport within volcanic edifices, and the evolution and stability of long-lived volcanic systems.
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Affiliation(s)
- Samuel T Thiele
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, 3800, Australia. .,Helmholtz Institute Freiberg for Resource Technology, Helmholtz-Zentrum Dresden-Rossendorf, 09599, Freiberg, Germany.
| | - Alexander R Cruden
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, 3800, Australia
| | - Steven Micklethwaite
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, 3800, Australia
| | - Andrew P Bunger
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA, 15269, USA.,Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA, 15269, USA
| | - Jonas Köpping
- School of Earth, Atmosphere and Environment, Monash University, Melbourne, 3800, Australia
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Geyer A, Álvarez-Valero AM, Gisbert G, Aulinas M, Hernández-Barreña D, Lobo A, Marti J. Deciphering the evolution of Deception Island's magmatic system. Sci Rep 2019; 9:373. [PMID: 30674998 PMCID: PMC6344569 DOI: 10.1038/s41598-018-36188-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 11/05/2018] [Indexed: 11/21/2022] Open
Abstract
Deception Island (South Shetland Islands) is one of the most active volcanoes in Antarctica, with more than 20 explosive eruptive events registered over the past two centuries. Recent eruptions (1967, 1969, and 1970) and the volcanic unrest episodes that happened in 1992, 1999, and 2014–2015 demonstrate that the occurrence of future volcanic activity is a valid and pressing concern for scientists, technical and logistic personnel, and tourists, that are visiting or working on or near the island. We present a unifying evolutionary model of the magmatic system beneath Deception Island by integrating new petrologic and geochemical results with an exhaustive database of previous studies in the region. Our results reveal the existence of a complex plumbing system composed of several shallow magma chambers (≤10 km depth) fed by magmas raised directly from the mantle, or from a magma accumulation zone located at the crust-mantle boundary (15–20 km depth). Understanding the current state of the island’s magmatic system, and its potential evolution in the future, is fundamental to increase the effectiveness of interpreting monitoring data during volcanic unrest periods and hence, for future eruption forecasting.
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Affiliation(s)
- A Geyer
- Institute of Earth Sciences Jaume Almera, ICTJA, CSIC, Lluis Sole i Sabaris s/n, 08028, Barcelona, Spain.
| | - A M Álvarez-Valero
- Departamento de Geología, Universidad de Salamanca, 37008, Salamanca, Spain
| | - G Gisbert
- Instituto de Geociencias, CSIC-UCM, Severo Ochoa 7, 28040, Madrid, Spain
| | - M Aulinas
- Departament de Mineralogia, Petrologia i Geologia Aplicada, University of Barcelona, Marti Franques s/n, 08028, Barcelona, Spain
| | | | - A Lobo
- Institute of Earth Sciences Jaume Almera, ICTJA, CSIC, Lluis Sole i Sabaris s/n, 08028, Barcelona, Spain
| | - J Marti
- Institute of Earth Sciences Jaume Almera, ICTJA, CSIC, Lluis Sole i Sabaris s/n, 08028, Barcelona, Spain
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