Larson Valley: West Pyramid, South Face, Infinite Curves; Larson Ridge, Central and West Summits
Antarctica, Heritage Range
The Larson Ridge is the name given to the east-west-oriented crest that borders the northern edge of the Larson Valley. Three main summits and a few bumps make for an excellent introduction to glacial mountaineering.
On January 12, 2018, the American-led team of Christine Amour-Levar, Claire Floriet, Patricia Jones, and Sandra Marichal-Ragot, with guides Chelsea Bomba and Yoshiko Miyazaki-Back, made the first ascents of the central (1,879m) and west (1,861m) summits on the Larsen Ridge.
Approaching from the east, the team climbed a broad snow slope steepening to 40–45° to gain the crest at 1,678m. Continuing west, they reached the east summit (1,812m, 79°29.779'S, 83° 53.519'W). To this point they had been following the route taken by Nick Lewis and Rob Smith on December 8, 2013.
The team then continued along the ridge for an hour to the central summit (79°29.692'S, 83°55.190'W) and from there another 45 minutes took them to the west summit (79°29.812S, 83°57.123'W). They then returned to the col between the west and central summits and descended glacial slopes southeast (40°) to the Larson Valley. The outing was graded F, and the climbers gave the unofficial names of "Mt. Gaia" to the central summit and "Mt. Malala" (after Nobel Peace Prize winner Malala Yousafzai) to the west summit.
Over the 13th and 14th, Floriet, Marichal-Ragot, and Miyazaki-Back made the first ascent of the south face of West Pyramid, a summit a little to the east of Larson Ridge. The three climbed slightly right of the U-bend of the prominent geological folds in the rock, then exited left up a snow ramp to gain the southwest ridge. The lower third gave 35–40° snow, and the middle mixed terrain was broken by snow bands that were often shallow and hollow over a rocky base. Ice was rarely encountered and rock protection sparse. Although it is possible to walk up the summit ridge to the top, this is exposed to wind and a more enjoyable and direct line is to follow steep snow left of the summit rock pyramid. The route was named Infinite Curves (PD, 5.7 M4- 45° snow). Descent was along the southwest ridge and west face, more or less following the route of the first ascent in December 2012. Toward the base the three moved south to gain the col between the Rennel Glacier and Larson Valley, and then crossed it to regain the foot of the face.
Nick Lewis, Antarctic Logistics & Expeditions, USA, supplied by Damien Gildea, Australia