Abstract: Applications of LANDSAT Imagery in Circum-Pacific Region

Floyd F. Sabins

The regional coverage provided by LANDSAT images is ideal for reconnaissance studies of the vast expanse of the Circum-Pacific area. Much of the area is obscured by clouds for extended periods, but the repetitive coverage by LANDSAT enables images to be acquired during cloud-free periods. Some applications of LANDSAT images of the Circum-Pacific region are: (1) investigation of relations between plate boundaries and hydrocarbon occurrences, (2) improvement of bathymetric charts, and (3) monitoring volcanic activity.

The plate boundaries associated with the margins of the Circum-Pacific are of three main configurations: transform faults, of which California is an example; simple subduction, as illustrated by the Andes; and island arcs with marginal seas in Indonesia. The major surface features of each boundary configuration are well expressed on LANDSAT images, which also show the positions of related hydrocarbon accumulations.

The shallow shelf seas of the area have attractive hydrocarbon potential and are being actively explored. Marine geophysical surveys may be hampered by submerged reefs and shoals that either are not charted or are inaccurately charted. The geometric accuracy of LANDSAT images and the ability to penetrate shallow, clear water are valuable for recognizing and mapping submerged navigation hazards, such as reefs and shoals, as for example in the Celebes Sea.

The Circum-Pacific area is surrounded by a belt of active volcanoes and studded with "hot spots" such as Hawaii. Volcanic landforms are readily recognized and mapped on LANDSAT images. The plumes of smoke and ash from eruptions have been detected on images.

LANDSATS 1 and 2 acquired images in the visible and photographic infrared bands of the electromagnetic spectrum. LANDSAT 3, which was launched in early 1978, provides an additional capability to acquire images in the thermal infrared spectral band. Active volcanic processes may be monitored on calibrated thermal infrared images as illustrated with aircraft examples of Mauna Loa and Kilauea.

AAPG Search and Discovery Article #90962©1978 AAPG 2nd Circum-Pacific Energy and Minerals Resource Conference, Honolulu, Hawaii