Imágenes satelitales para obtener información sobre potencial geotérmico

2 March, 2013 | By More

IMAGENES SATELITALES PARA OBTENER INFORMACION SOBRE POTENCIAL GEOTÉRMICO

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Por Illán Arribas M.Sc.; Editado por Dora de Alonzo PhD; 2 de Marzo de 2013

Aster image

Imagen ASTER [Wikimedia Commons]

La investigación de la geotermia en Chile es objeto de numerosos trabajos de investigación [1-3].  El investigador Francisco J. Gutierrez y su equipo han publicado recientemente su trabajo sobre el uso de imágenes de satélite como una poderosa herramienta para predecir el potencial geotérmico [3].

En el estudio chileno de la región central de los Andes fueron utilizadas, imágenes de satélites con sensores ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), así como también, datos de terreno de diez sitios seleccionado para realizar los cálculos.

Las imágenes de satélite requieren procesamiento para ser utilizadas en el bosquejo de mapas geotérmicos. Gutiérrez y equipo aplicaron una nueva variable a las imágenes, que consiste en la sustracción de la anomalía de la temperatura que aparece debido a diferencias de altitud, el llamado, empinamiento.

Otras correcciones de imagen comprenden la transmitancia de la tierra, el albedo (reflejo de la tierra), la pendiente de diferentes superficies, inercia térmica y posición geográfica.

Gutiérrez y su equipo propuso el uso de una nueva variable “K” (medida en ° C/km) para corregir las imágenes de satélite brutas, interpretado como la anomalía debido a diferentes altitudes. Esta variable es similar a la Tasa de Lapso Ambiental (6,49 ° C/km a cero altura) establecidas por la organización de Aviación Civil Internacional.

El modelo chileno fue validado con datos del campo, pero se encontró que sólo era válido para algunos casos particulares. Por ejemplo, el modelo está limitado por la resolución de las imágenes de satélite y sólo permite detectar anomalías termales en zonas con una superficie superior a 90 m2.

Esto proporciona un paso adelante a los modelos americanos anteriores [4] que no incluyen la diferencia de temperatura relacionada altitud superficial de la tierra.

MATERIAL CITADO:

[1] Alfredo Lahsen, Chilean geothermal resources and their possible utilization, Geothermics, Volume 17, Issues 2–3, 1988, Pages 401-410. (http://www.sciencedirect.com/science/article/pii/0375650588900685)

[2] Fabián Sepúlveda, Alfredo Lahsen, Sylvain Bonvalot, José Cembrano, Antonia Alvarado, Pablo Letelier, Morpho-structural evolution of the Cordón Caulle geothermal region, Southern Volcanic Zone, Chile: Insights from gravity and 40Ar and 39Ar dating, Journal of Volcanology and Geothermal Research, Volume 148, Issues 1–2, 15 October 2005, Pages 165-189,

(http://www.sciencedirect.com/science/article/pii/S0377027305001496)

[3] Francisco J. Gutiérrez, Martín Lemus, Miguel A. Parada, Oscar M. Benavente, Felipe A. Aguilera, Contribution of ground surface altitude difference to thermal anomaly detection using satellite images: Application to volcanic/geothermal complexes in the Andes of Central Chile, Journal of Volcanology and Geothermal Research, Volumes 237–238, 1 September 2012, Pages 69-80.

(http://www.sciencedirect.com/science/article/pii/S0377027312001540)

[4] M.F. Coolbaugh, C. Kratt, A. Fallacaro, W.M. Calvin, J.V. Taranik, Detection of geothermal anomalies using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) thermal infrared images at Bradys Hot Springs, Nevada, USA, Remote Sensing of Environment, Volume 106, Issue 3, 15 February 2007, Pages 350-359,

(http://www.sciencedirect.com/science/article/pii/S0034425706003154

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SATELLITE IMAGING TO GAIN INSIGHT ABOUT GEOTHERMAL POTENTIAL

By Illán Arribas M.Sc.; Edited by Dora de Alonzo PhD; March 2, 2013

Aster image

ASTER image [Wikimedia Commons]

The investigation of geothermal energy potential in Chile is the subject of many research studies [1-3]. Researcher Francisco J. Gutierrez and his team have recently published their work on the use of satellite imaging as a powerful tool to predict the geothermal potential [3].

In the Chilean study from the Andes central region, images from satellites with ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensors, as well as ground data from ten selected sites were used to perform the calculations.

Satellite images require processing in order to sketch geothermal maps. Gutierrez and coworkers applied a new processing variable to the images, which consist on the subtraction of the temperature anomaly that appears because of altitude differences, the so called, steep relief.

Other image corrections comprise earth transmittance, the albedo (earth’s reflection), the slope of different surfaces, thermal inertia, and geographic position.

Gutierrez and his team proposed the use of a new variable “K” (measured in °C/km) to correct the raw satellite images, interpreted as the anomaly due to different altitudes. This variable is similar to the Environmental Lapse Rate (6.49 °C/km at zero altitude) set by the International Civil Aviation Organization.

The Chilean model was validated with data from the field, but it was found to be only valid for particular cases. For instance, the model is limited by the resolution of the satellite images, and only allows detecting thermal anomalies in zones with a surface greater than 90 m2.

This provides a step further to previous American models [4] which did not include the difference in temperature related to ground surface altitude.

 

REFERENCES

[1] Alfredo Lahsen, Chilean geothermal resources and their possible utilization, Geothermics, Volume 17, Issues 2–3, 1988, Pages 401-410. (http://www.sciencedirect.com/science/article/pii/0375650588900685)

[2] Fabián Sepúlveda, Alfredo Lahsen, Sylvain Bonvalot, José Cembrano, Antonia Alvarado, Pablo Letelier, Morpho-structural evolution of the Cordón Caulle geothermal region, Southern Volcanic Zone, Chile: Insights from gravity and 40Ar and 39Ar dating, Journal of Volcanology and Geothermal Research, Volume 148, Issues 1–2, 15 October 2005, Pages 165-189,

(http://www.sciencedirect.com/science/article/pii/S0377027305001496)

[3] Francisco J. Gutiérrez, Martín Lemus, Miguel A. Parada, Oscar M. Benavente, Felipe A. Aguilera, Contribution of ground surface altitude difference to thermal anomaly detection using satellite images: Application to volcanic/geothermal complexes in the Andes of Central Chile, Journal of Volcanology and Geothermal Research, Volumes 237–238, 1 September 2012, Pages 69-80.

(http://www.sciencedirect.com/science/article/pii/S0377027312001540)

[4] M.F. Coolbaugh, C. Kratt, A. Fallacaro, W.M. Calvin, J.V. Taranik, Detection of geothermal anomalies using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) thermal infrared images at Bradys Hot Springs, Nevada, USA, Remote Sensing of Environment, Volume 106, Issue 3, 15 February 2007, Pages 350-359,

(http://www.sciencedirect.com/science/article/pii/S0034425706003154

 

 

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Category: Energía Geotérmica

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