Kīlauea Volcano in Hawaii experienced its first summit eruption in 26 years when a new vent along the east wall of Halema'uma'u Crater opened in March 2008. Since that time, the vent has become wider as parts of the wall around it became unstable and collapsed into the active lava lake within the vent, sometimes triggering small explosions. Richter et al. have monitored surface deformation in the area around the new vent since 2008 using interferometric synthetic aperture radar (InSAR) from the TerraSAR-X satellite along with a digital elevation model of the topography based on lidar data. The scientists were able to generate interferograms (a type of image) with a pixel resolution of about 3 meters, which revealed centimeter-scale subsidence in the area within 100 meters of the vent rim. They note that this deformation cannot be detected by other techniques.