On 1 August 1999, a group from the Societe de Volcanologie Geneve ascended the ice- and rock-covered summit. On the way up the N flank they saw vertical coal deposits below 2,450 m elevation, reaching thicknesses of tens of meters. Above 4,000 m elevation huge blocks were seen that appeared to have traveled from ~1 km above. Just below the summit were large sulfur-bearing blocks that appear to be mixed with a clay- like material. Within 100 m of the N rim of the summit chunks of pure sulfur were observed. The circular summit crater was ~150 m in diameter. In the center of the crater lay a small frozen lake approximately 40 m across. From the N rim of the summit, an active fumarole could be seen to the south.