On September 29, 2016, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this false-color image (MODIS bands 7-2-1) showing volcanic activity in the South Sandwich Islands.
Located in the South Atlantic Ocean, the uninhabited South Sandwich Islands include several active stratovolcanoes. Due to their remote location, these volcanoes are some of the least studied in the world, though satellites often catch them erupting.
The combination of clouds and ice can make it difficult to see plumes of volcanic ash in natural color imagery. Using portions of the electromagnetic spectrum that are typically invisible to the naked eye—such as infrared—enables satellites to distinguish ice from ash and clouds, or even reveal hot spots underneath a smoky wildfire.
References & Resources
- Earth Observatory (2016), Signs of an Eruption on Bristol Island.
- Earth Observatory (2014), Why is that Forest Red and that Cloud Blue? How to Interpret a False-Color Satellite Image.
NASA Earth Observatory image by Joshua Stevens, using MODIS data from the Land Atmosphere Near real-time Capability for EOS (LANCE). Caption by Joshua Stevens.
