TY - JOUR

T1 - Determining physical and mechanical volcanic rock properties via reflectance spectroscopy

AU - Schaefer, Lauren N.

AU - Kereszturi, Gabor

AU - Villeneuve, Marlene

AU - Kennedy, Ben

N1 - Publisher Copyright: © 2021 The Authors

PY - 2021/11/9

Y1 - 2021/11/9

N2 - There are currently no reliable methods to determine rock physical and mechanical properties that are not labor or resource intensive, especially at the scale of volcanoes. Using mineralogical-physical-mechanical relationships, we suggest it is possible to derive rock properties from rapid, non-invasive reflectance spectroscopy measurements. To demonstrate this potential, we correlate the physical and mechanical properties of variously altered andesitic volcanic rocks to laboratory reflectance spectroscopy using statistical analysis. Several rock properties, including density, connected porosity, strength, magnetic susceptibility, and elasticity, correlate with reflectance spectroscopy in both the visible and short-wave infrared parts of the electromagnetic spectrum. We attribute these correlations to the presence and degradation (i.e. weathering or hydrothermal alteration) of iron-bearing minerals such as pyroxene, magnetite, and pyrite, which reflect changes to both rock properties and reflectance spectroscopy measurements. Results support the use of transfer functions to estimate rock properties directly from reflectance spectroscopy. Ultimately, aerial or satellite imaging spectroscopy could be used to create geotechnical maps at volcano scale.

AB - There are currently no reliable methods to determine rock physical and mechanical properties that are not labor or resource intensive, especially at the scale of volcanoes. Using mineralogical-physical-mechanical relationships, we suggest it is possible to derive rock properties from rapid, non-invasive reflectance spectroscopy measurements. To demonstrate this potential, we correlate the physical and mechanical properties of variously altered andesitic volcanic rocks to laboratory reflectance spectroscopy using statistical analysis. Several rock properties, including density, connected porosity, strength, magnetic susceptibility, and elasticity, correlate with reflectance spectroscopy in both the visible and short-wave infrared parts of the electromagnetic spectrum. We attribute these correlations to the presence and degradation (i.e. weathering or hydrothermal alteration) of iron-bearing minerals such as pyroxene, magnetite, and pyrite, which reflect changes to both rock properties and reflectance spectroscopy measurements. Results support the use of transfer functions to estimate rock properties directly from reflectance spectroscopy. Ultimately, aerial or satellite imaging spectroscopy could be used to create geotechnical maps at volcano scale.

KW - Transfer function

KW - Andesite

KW - Hydrothermal alteration

KW - Weathering

KW - Iron-bearing mineral phases

KW - Clay

KW - Short wave infrared

KW - Visible spectrum

KW - Reflectance spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85115035871&partnerID=8YFLogxK

U2 - 10.1016/j.jvolgeores.2021.107393

DO - 10.1016/j.jvolgeores.2021.107393

M3 - Article

VL - 420.2021

JO - Journal of volcanology and geothermal research

JF - Journal of volcanology and geothermal research

SN - 0377-0273

IS - December

M1 - 107393

ER -