P085-01
Spectral Characterization of Lava Fields and Glaciovolcanic Sand Seas of Iceland: Implications for Mars
Wednesday, 16 December 2020: 10:01
Virtual
Morgan L Cable1, Alexander Michael Sessa2, Anna Simpson2, Erika Rader3, Ashley M Hanna4, Elena Amador1,5, Mark C Helmlinger6, Diana Gentry7, Amanda M. Stockton8 and FELDSPAR Team, (1)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (2)Georgia Institute of Technology, Atlanta, GA, United States, (3)University of Idaho, Geology, Moscow, ID, United States, (4)Georgia Institute of Technology Main Campus, Atlanta, GA, United States, (5)California Institute of Technology, Pasadena, CA, United States, (6)Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States, (7)NASA Ames Research Center, Biospheric Science Branch, Moffett Field, CA, United States, (8)Georgia Institute of Technology, School of Chemistry & Biochemistry, Atlanta, GA, United States
Abstract:
The lava fields and glaciovolcanic sandur (sand seas) of Iceland are often cited as suitable analogs for certain regions of Mars, as these areas have undergone similar geologic processes to what may have occurred or still be occurring on the Red Planet. These areas and others that exhibit volcano-ice interaction may contain suitable environments for life, or evidence of past life, and are therefore high priority targets for future exploration. Visible to short wavelength infrared (SWIR) orbital observations of Mars have been a useful tool in identifying and mapping primary and alteration minerals across the martian surface. However, it is unclear if orbital instruments may misidentify areas due to lower spatial sampling, in particular for darker regions with low absolute reflectance.
We selected two lava fields and two glaciovolcanic sandur of Iceland to explore at various spatial scales. We obtained visible to SWIR reflectance measurements at 10 cm, 1 m, 10 m, 100 m and 1 km scales, and compared the summary products extracted from these spectra to measurements of elemental composition (X-ray fluorescence), mineralogy (thin sections of the lava sources), grain size and moisture content. While some data were consistent for a given site and scale, others (such as hydration bands and moisture content) were not, indicating that spectral information obtained by remote sensing may require supporting data from other observations to provide a more accurate interpretation of an area in some cases. As might be expected, averaging spectra collected at the 10-cm scale over a larger area yielded a loss of unique spectral features, but interestingly this occurred even going from the 10-cm to 1-m scale, and was prevalent even in sand seas that might be expected to be more homogeneous (well-mixed) over a given area. We will describe the implications for such observations in terms of interpreting remote sensing observations of Mars, in particular for identifying areas targeted as landing sites for future in situ missions.
