Abstract: Thermal Infrared Applications Compared to Petroleum-Based Hydrocarbon Site Investigation Reality

Philip B. Chandler

Thermal infrared remote sensing techniques have been evaluated with respect to environmental problems ever since military data was declassified and released. The first civilian sensors began to be available in the late 1960s and were immediately seen to have many environmental roles. An early surprise was the ability to distinguish oil from seawater at the 1969 Santa Barbara, California oil spill as determined by staff at North American Rockwell (NAR). As a result other petroleum-related targets were evaluated with NAR sensor overflights, including many areas of refinery operation in region of Los Angeles, California. Fifteen to twenty years later it became recognized that many of these refineries had been discharging large volumes of petroleum and product to the underlying ground water over some unknown period of time. Early airborne thermal sensor data had not yielded significant information at refinery sites regarding on-going or impending environmental threat to ground water. The subsequent "snake oil" concerning air- and space-borne remote sensing applications from various sources has not really changed that situation. Even with the improvement of sensor system spatial and spectral resolution, availability of multi-spectral sensors and the current extraordinary data processing techniques, the only tools that fully define threat to the environment from discharges at these refinery sites remains appropriately targeted and spaced multi-depth direct soil sampling and groundwater monitoring. In the bulk of environmental investigation situations, remote sensing remains useful in its earliest incarnation, aerial photography, to indirectly reveal, through change-detection evaluation, potential source areas, e.g. now-vanished aboveground tanks, sumps and surface piping. These areas can then be subjected to investigation below ground surface through direct contact techniques. Ancillary use of geophysics, including ground penetrating radar has value, but does not alone provide sufficient information to support regulatory decisions.

AAPG Search and Discovery Article #90958©1995 AAPG Pacific Section Meeting, San Francisco, California