#InSAR

In a recent “Volcano Watch” article, we learned about a remote sensing technique known as InSAR. This method of using satellite radar signals to detect changes to the surface of the earth has been very beneficial for monitoring of active volcanoes, especially in remote locations where it is difficult to install ground based geophysical sensors.

Hawaiian Volcano Observatory scientists are constantly using InSAR (Interferometric Synthetic Aperture Radar) images and other tools to track the movement of magma within Hawaii’s volcanoes in order to identify the warning signs of impending eruptions. 

What are symptoms leading up to an eruption? The main player in monitoring volcanoes is seismicity—the frequency and magnitude of earthquakes.  When magma enters the volcanic edifice, it accumulates and makes space for itself by compressing many tiny void spaces.  Continued filling by magma creates pressure on the walls of reservoirs, causing slip, faults, or cracking in the surrounding brittle rock.  All these motions result in the generation of earthquakes.