Using Remotely Sensed Thermal Infrared Multispectral Data and Thermal Modeling to Estimate Lava Tube Roof Thickness atKilauea Volcano, Hawaii

摘要

Thermal Infrared Multispectral Scanner (TIMS) data are processed to yield surface temperatures over the lava tube system of Kilauea Volcano, Hawaii. TIMS is a 6-band airborne longwave infrared (8 μm to 12 μm) multispectral imaging system built and operated by the National Aeronautics and Space Administration (NASA). The data analyzed were collected in 1988 and are part of the Compiled Volcanology Data Set collection of Glaze et al., (1992). The primary goal of the analyses is to utilize the TIMS-derived surface temperatures to estimate lava tube roof thickness (LTRT). There is a paucity of studies that have utilized remotely-sensed imaging spectrometry data to estimate LTRT-a component important to understanding (and modeling) the thermal field of lava tube systems. Lava tube systems, in turn, are important to the emplacement of areally extensive lava flows on earth and on other planets. An in-scene atmospheric compensation method was applied to the data followed by a normalized emissivity method temperature/emissivity separation algorithm to obtain surface temperature. Surface temperature measurements are then compared to modeled temperatures in order to estimate lava tube roof thickness. Modeled temperatures are calculated via finite element analysis. Boundary conditions of the finite element models are derived from analyses of the TIMS data, independent knowledge of lava liquidus and solidus temperatures, and crustal heat-flow geophysical data. A TIMS plus modeling-derived LTRT agrees with estimates based on field observations. The TIMS data are described as are all processing and analysis methods. The thermal modeling is also described as is an effort to build a lookup table for LTRTs to be used in conjunction with surface temperature measurements. Archived data such as those exploited here provide a historical context particularly for terranes which may undergo relatively rapid change-such as the lava flow fields of Kilauea Volcano.