Studying Volcanoes With Satellites
Earth Observation Systems Can Assist in Volcanic Research
Volcanoes can be dangerous to study. Luckily for volcanologists, the vast array of satellites orbiting our planet can provide valuable information from a safe distance.
Volcanoes are known for both their beauty and their danger. Volcanologists from all over the world risk their lives daily to gain a better understanding of how these geological structures work, and the implications for those living near volcanoes. But new technology has enabled these scientists to get a closer view of volcanoes than they ever have before, without ever being in danger.
Satellites circling our globe have given scientists valuable information about almost every planetary process from the top of the atmosphere right down to the very bottom of the ocean. Within the past two decades, these same satellites have emerged as a new tool for studying almost every aspect of volcanological processes. Some of the volcanic processes that can be studied using satellites are:
- Eruption clouds in the atmosphere, including ash clouds and gas clouds
- Changes in the shape of volcanoes
- Hot spots, also known as thermal anomalies
- Lava extrusions
Volcanic Ash and Gas Clouds
When a volcano erupts, very often ash and gas are ejected into the atmosphere, where they can remain for hours to days, depending on the size of the eruption. One classic example of this is the 1991 eruption of Mt. Pinatubo in the Philippines. When this volcano erupted, it sent a huge cloud of ash and sulfur dioxide billowing into the atmosphere. This cloud was observed and studied using satellite imagery and scientists were able to track the cloud as it circled around the globe.
More recently, volcanic eruptions from Anatahan Volcano, located in the Mariana Island Chain in the Pacific Ocean, has been erupting sulfur dioxide and ash into the atmosphere, resulting in hazards to aviation operations in the area. By tracking these clouds using satellite imagery, volcanologists can warn aircraft in the area and pilots can avoid the hazardous clouds.
Volcano Deformation
Changes in the shape of a volcano can alert volcanologists to impending activity. As magma rises and fills the magma chamber feeding a volcano, the surrounding mountain will inflate like a balloon. Devices on the volcano linked to satellites, such as the global positioning system, or GPS, can measure even the most subtle changes on the surface of a volcano. Scientists can be alerted using automated systems when a large change in shape is recorded, suggesting that magma is on the move.
Hot Spots and Lava Flows
Thermal anomalies and lava extrusions can also be detected using satellites. The heat from thermal anomalies and lava is high enough to be detected using thermal infrared sensors located on most earth observing satellites. Because the signal being detected is in the thermal infrared region of the spectrum, these processes can be seen just as easily at night as during the day. Volcanologists can watch a volcano and see when magma is rising through the volcano’s conduit, creating a hot spot at the summit, or when lava is flowing down the flanks of the volcano. All without having to be anywhere near the volcano.
Source: Smithsonian Institute's Global Volcanism Program
