A huge, unstable chunk of glacier is blocking the route up Mount Everest from Base Camp in Nepal just as peak climbing season gets under way in the Himalayas. Icefall doctors – who fix ropes and ladders on the lower part of the route up the world's highest peak - can find no way around the 100-foot-high (30m) block of ice just below Camp 1. They say the only option is to wait for the ice block, called a serac, to melt – which they hope will happen within days. The delay means preparations are weeks behind schedule for the spring season when weather for Everest ascents is usually best, and fears are growing that climbers will be queuing to reach the summit again this year. Purnima Shrestha, a prominent climber and photographer from Nepal, is currently acclimatizing to summit Everest for the sixth time. We usually climb between Camp I, Camp 2, and Camp 3 back and forth during this acclimatizing process. Delays in the opening of the route have added concerns of possible 'traffic jams' to the peak this year, she told the BBC from Base Camp. The icefall doctors work for the Sagarmatha Pollution Control Committee (SPCC) that is responsible for securing ropes as far as Camp 2 on Everest, which stands 8,848.86m (29,031 feet) above sea level. They reached Base Camp three weeks ago. By this stage in April, they would normally have fixed the route as far as Camp 3 but are still blocked by the chunk of glacier about 600m from Camp 1. SPCC base camp coordinator Tshering Tenzing Sherpa stated, We haven't found artificial ways to melt it so far, so we don’t have any options other than to wait for it melting and crumbling itself. Nepal's Department of Tourism is exploring options, including airlifting teams to Camp 2. As favorable weather is expected only until the end of May, there is hope that the rope-fixing work to Camp 2 will be completed promptly. Shrestha emphasized that even if the route opens soon, the climbing window could be sharply reduced this season. Despite challenges posed by international events affecting travel, a significant number of climbers are anticipated this year, with 367 permits issued thus far, mainly to Chinese climbers.