Project Details
Projekt
Permeability’s role around magma bodies: a way for gradually deforming or suddenly erupting
Applicant
Dr. Cristian Montanaro
Subject Area
Geology
Mineralogy, Petrology and Geochemistry
Mineralogy, Petrology and Geochemistry
Term
from 2018 to 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 398512416
New evidence collected during the first two years of the project MO3508/1-1 indicated that at Krafla the occurrence of explosive eruptions related to magmatic intrusion (as the 1724 Víti eruption), were strongly controlled by the shallow geological and hydrothermal settings, rather than the presence of a conductive boundary layer surrounding the magma body. A detailed stratigraphic reconstruction of the breccia erupted from Víti crater, and the characterization of the lithologies involved in the explosions, allowed to reconstruct the pre-eruptive setting, fingerprint the eruption trigger and source depth, and reveal the eruption mechanisms.The objectives of the research proposed in this renewal proposal are aimed to further constrain porosity-permeability-strength of lithologies hosting shallow hydrothermal system portions at Krafla, and assess their effect on the potential volcanic hazards related to magmatic-hydrothermal eruptions - and on the geothermal exploitation, in line with the scientific program suggested for the IMPROVE project. Key objectives are to i) quantify the influence of hydrothermal alteration on the physical properties of rocks from the shallow portion of Vesturhlíðar hydrothermal system, and ii) quantify the critical conditions resulted in failure of cap rocks at Víti, and estimate energetics of the eruption. Remarkable findings from the first two years of project highlight the role of low porosity-permeability lithologies that can both mask areas with hot fluids (e.g. north of Víti), and/or act as a barrier in upflow zones possibly producing overpressure conditions that lead to explosive failure in case of magmatic intrusion. In this light, the data and samples already collected, together with investigation planned within the IMPROVE experiments will provide a unique opportunity to foster our understanding the lithological control on fluid circulation, alteration and explosive potential within geothermal areas. Such understanding is pivotal to (a) constrain the (physical and spatial) priming conditions for explosive failure in perturbed geothermal areas, (b) explore the possibilities for detecting covert geothermal resource. Keywords: hydrothermal eruptions; experimental volcanology; Krafla geothermal area; IMPROVE; permeability; rock petrophysics; P-T perturbations; decompression; brittle failure
DFG Programme
Infrastructure Priority Programmes
Co-Investigator
Professorin Dr. Bettina Scheu
