Patagonia, Argentina #3446

#3446 Patagonia, Argentina by JVPD
Mosaic consisting of 6 NASA images showing two examples of SRTM radar images (center) with comparisons to images acquired by the Landsat 7 satellite in the visible wavelengths (left) and an infrared wavelength (right). Both sets of images show lava flows in northern Patagonia, Argentina. In each case, the lava flows are relatively young compared to the surrounding rock formations. Generally, the upper flow sits atop much lighter bedrock, providing good contrast and making the edges of the flow distinct. However, the lower flow borders some rocks that are similarly dark, and the flow boundaries are somewhat obscured. Meanwhile, in the radar images (center), image brightness corresponds to surface roughness (and topographic orientation) and substantial differences between the flows are visible. Much of the top flow appears dark, meaning it is fairly smooth. Consequently, it forms little or no contrast with the smooth and dark surrounding bedrock and thus virtually vanishes from view. However, the lower flow appears rough and bright and mostly forms good contrast with adjacent bedrock such that the flow is locally more distinct here than in the visible Landsat view. For further comparison, infrared Landsat images (right) again show image brightnesses related to mineral chemistry, but the lava flows appear lighter than in the visible wavelengths. Consequently, the lower lava flow becomes fairly obscure among the various surrounding rocks, just as the upper flow did in the radar image. The various differences among all of these images illustrate the importance of illumination wavelength in image interpretation. The Landsat 7 Thematic Mapper images used here were provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, South Dakota.

Photo Credit: NASA/JPL/NIMA [0003-0701-0820-0937] by 0003

Similar Images:

#3296 Lava Plateaus, Argentina by JVPD
#3261 Lava Plateaus, Argentina by JVPD
#3293 3D of Las Bayas, Argentina by JVPD
#3294 Laguna Mellquina, Andes Mountains, Argentina by JVPD
#3245 Near Zapala, Argentina by JVPD
#3285 Corral de Piedra, Argentina by JVPD
#3284 Zapala, Argentina by JVPD
#3476 Basalt Cliffs, Patagonia, Argentina by JVPD
#3414 Basalt Cliffs by JVPD
#3276 Laguna Mellquina, Andes Mountains by JVPD
#3267 Las Bayas, Argentina by JVPD
#3431 Meseta de Somuncura by JVPD
#3386 Patagonia by JVPD
#3401 Meseta de Somuncura, Patagonia, Argentina by JVPD
#3287 Corral de Piedra by JVPD
More Argentina Photos


argentina, geography, jpl, lava flows, nasa, patagonia, patagonia argentina