Ojos del Salado was even higher than Ojos del Salado. Later measurements using more precise equipment showed that Ojos del Salado is about higher than Pissis. Furthermore, in 2007 a Chilean–Argentine–European expedition organized by Andes Magazine and Azimut 360 performed a survey on both Ojos del Salado and Monte Pissis using more accurate instruments. It found the former to be and the latter Although this fits within recent handheld GPS surveys, which have estimated the mountain to be between and , the vertical error margin of the expedition's equipment, , leaves uncertainty as to the mountain's more precise altitude. Ojos del Salado has
Ojos del Salado reports indicate the absence of glaciers on Ojos del Salado. Permafrost exists on the mountain and its melting nourishes several lakes; one lake fed by a creek lies at altitude. Ojos del Salado is an active volcano, but the question of whether it should be considered "currently" (or "historically") active is arguable. According to the Smithsonian Institution's Global Volcanism Program, the most recent known eruption was about 1,300 years ago, with a large margin of uncertainty. However, there is also some evidence for a minor ash emission in 1993, which would definitely qualify the volcano as historically active. The presence