Relating Small-Scale Texture Of Basaltic Lava Flows To Thermal Inertia

Thermal inertia measures a materials resistance to temperature change over time. It is defined as I = (k c ), with k as the thermal conductivity, c as the thermal capacity, and as the density. It can be estimated from thermal remote imagery using the apparent thermal inertia, defined as ATI = (1- ) / T, with T as the temperature difference over some time, and as the albedo. We seek to understand how variations in the thermal inertia of three young basaltic lava flows relate to variations in their small-scale texture. This will be facilitated by collecting thermal images in the field with a Forward-Looking Infra-Red (FLIR) camera, analyzing samples in the lab, and examining satellite remote sensing data. The lava flows being studied are Carrizozo, Aden Crater (Potrillo Field), Paxton Springs, and McCartys (Zuni-Bandera Field), located in central and southern New Mexico. We collected ten samples from the lava flows, four pahoehoe from Carrizozo, three `a`a from Paxton Springs, and three pahoehoe from Aden Crater. Thermal images were collected for all four lava flows at 30 sec or 1 min intervals over the course of 30 to 180 minutes during sunrise and sunset. Wind speeds were measured during image collection with an anemometer. Samples will be characterized by measuring the density by pycnometry, the heat capacity by differential scanning calorimetry (DSC), the thermal diffusivity by Light Flash Analysis (LFA), and their geochemistry using X-ray Fluorescence (XRF). One-inch blocks were cut from the samples for heating in the lab furnace and monitoring their cooling with the FLIR camera which, can then be compared to observe the effects of sample mass, vesicularity, crystallinity, and surface area have on the cooling rate. The results should enable more refined remote mapping of lava flow textures on Earth and other planetary bodies.