Prelude: Mountains in an Uncertain World* - Impact of Global Changes on Mountains: Responses and Adaptation - page 11

Photo 2. Nepal, Khumbu. Imja Lake from the air in 2007. The newly regarded major threat
to outbreak of the lake is the course of its drainage through the end moraine via the series of
small lakes (Photograph kindly supplied by Sharad P. Joshi, ICIMOD, Kathmandu).
Color image of this figure appears in the color plate section at the end of the topic.
station, and every bridge for about 60 kilometres downstream. The
fi rst published assessment of the event and its tragic consequences was
prepared for the International Centre for Integrated Mountain Development
(ICIMOD) based in Kathmandu (Ives 1986). This led to identifi cation of the
Imja Glacier and its rapidly expanding supra-glacial lake a few kilometres
south of Everest.
In 1956 there was no lake on the surface of the Imja Glacier; by 1985
there was a lake more than 1,000 metres long and 500 metres wide. Today
that same lake exceeds 2.5 km in length. Between 2002 and 2012, its depth
increased from 98 m to 116 m and its estimated volume from 35 million m³
to 61.6 million m³ (Watanabe et al. 2009, Byers et al. 2014).
Today Imja Lake, generally attributed to climate warming and glacier
melt, has been characterized in the news media worldwide as the most
dangerous glacial lake in the Himalaya. Should its apparently fragile end
moraine dam be breached, a wall of water, mud and boulders is predicted
to severely damage the small Sherpa village of Dingboche, breach the
Everest base camp trail within three hours, and continue its devastation
far downstream. Yet this scenario is disconcertingly under-reported by
journalists concentrating on the dangers of climbing Everest as well as the
environmental impacts of thousands of trekkers making their way to the
base camp. Imja Lake has also become the object of projections of large scale