St. Catharines 2004
Technical Program

SS19:  Molecules to Planets: Infrared spectroscopy in geochemistry, exploration geochemistry and remote sensing 
Organizers / Organisateurs:  Penny King, Mike Ramsay, Gregg Swayze
Room / Salle:  AS 201

Date:  05/12/2004
Time:  9:40 AM
Presenter:  Jeffrey M. Byrnes

Infrared spectroscopic analysis of synthetic glasses: application to basaltic lava flow emplacement

Byrnes1, J.M., Ramsey, M.S., and King2, P.L. 1Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, PA, USA, 15260-3332, 2Department of Earth Sciences, University of Western Ontario, London, ON, N6A 5B7

To better assess and mitigate volcanic hazards associated with lava flows using infrared data, an improved understanding of the relationship between laboratory, field, and remote sensing data coupled with improved knowledge of flow field development is needed. Quantifying the physical changes that occur in silicate melts using infrared emission spectroscopy will provide a means to examine the affects of vesicle formation and distribution, surface chill coats, and short-range crystal lattice formation on the emitted infrared spectrum. The linkage between IR spectroscopy and lava cooling will yield important constraints for application to the basaltic lava flow field development. A suite of glasses will be synthesized in the Experimental Analysis Laboratory at the University of Western Ontario to represent a range of compositions and vesicle contents. Spectra of these samples will be collected using the FT-IR spectrometer housed in the University of Pittsburgh’s IVIS Laboratory. This will provide a first-order comparison between the spectral morphology and the crystallinity of the samples.  The second phase of the study will be to collect spectra of samples cooling from above liquidus temperatures. The spectrometer will be fit with a heating/cooling/photography stage in order to provide a means to melt the synthetic glasses, collect their emitted thermal spectra, and obtain coincident digital images of the samples. Chilled samples will be analyzed using XRD analysis to determine the percentage and compositions of the crystals formed. These results will be compared with thermal emission spectra of basalt samples that represent distinct styles of lava flow emplacement that have been collected at the 1969-1974 Mauna Ulu flow field (Kilauea Volcano, Hawai'i, USA).

Results from these analyses can then be applied to thermal data collected in the field and by satellite for active lava flows. Field investigations of such flows at the active Pu'u 'O'o-Kupaianaha flow field (Kilauea Volcano) have begun and seek to understand the effects of temperature and glassy crusts on retrieved emissivity. The integration of laboratory, field, and spacebourne remote sensing analyses will provide quantitative constraints on the effects of vesiculation and crystallization, crust formation and spallation, and cooling on the emplacement and inflation of basaltic lava flows. For example, understanding the temporal and spatial changes in thermal emission will allow a more accurate estimate of radiative heat flux, which may ultimately be used to calculate the local eruption rate.