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Self-guided virtual field trip of the Delta del Orinoco
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| The Orinoco
River carries large volumes of sand and clay eroded from the northern Andes and other
parts of the South American continent. It has built
up a thick wedge of river and delta deposits at the northeast edge of the South American
continent. This area is now a remote wilderness of large rivers, tropical wetlands, dense
jungle, savannas, and coastal mangroves. Because the area remains inaccessible by land,
initial geo-environmental analysis is carried out using an array of satellite images to
look at variations in vegetation characteristics and landforms to help determine where our
field expeditions should carry out ground-based investigations. In this self-guided tour, we invite you to first look at the satellite images, and then select the field sites you would like to "visit" on the ground. Links are provided between the topical summaries for different parts of the delta and the tour. As a base map you will use an image produced by the Japanese JERS-1 satellite. This satellite uses Synthetic Aperture Radar to emit and receive reflected pulses of electromagnetic energy. The reflected energy is used to image the Earth's surface. The radar pulses pass unhindered through clouds, which is an important advantage over other imaging technologies in this humid and cloudy region, but this satellite collects only one spectrum (radar black and white). You are invited to zoom in closer to the image by clicking inside the blue boxes In some areas, we also provide Landsat Thematic Mapper (TM) images. The Landsat TM sensor senses electromagnetic energy in seven bands ranging from the blue end of the visible spectrum (wavelength- .45 - .65 microns) to the thermal infrared (12.5 microns). These various wavelengths are then processed to produce false color images that highlight variations in vegetation and land-surface reflectivity. To look at photographs of the landforms and vegetation patterns in various segments of the delta, click on the red dots. Several radiocarbon age dates of delta sediments are indicated by blue dots. The Bureau of Economic Geology is working closely with the UT Center for Space Research in image acquisition and processing. |
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Please send comments,
questions, or suggestions to Edgar Guevara.
Copyright 1998 Bureau of Economic Geology