Gilbertson twins remeasure peaks and identify new national high points

Fraternal twins Eric and Matthew Gilbertson, both mechanical engineers, have been climbing and remeasuring mountain summits around the world. Eric returned to Southern Colorado and measured East Crestone, finding it one-third of a foot taller than the well-known Crestone Peak; that result was published last month in the journal Progress in Physical Geography: Earth and Environment.

The brothers run a project called Country Highpoints and, between them, have climbed 149 peaks. In late November they published a paper establishing new high points in five countries, including Sare Firasu Hill in Gambia, Jabal Ferwa in Saudi Arabia, Alpomish in Uzbekistan, Mount Atilakoutse in Togo and Mount Ronde in Guinea-Bissau.

Their field method begins with satellite digital elevation models to identify candidate summits and then uses Differential Global Navigation Satellite System units to collect hours of data on each top, producing uncertainties of about an inch; for example, their Saudi measurements showed Jabal Ferwa about 10 feet higher than Jabal Sawda, and their Uzbekistan measurement recorded Alpomish at 15,314 feet and 11.52 inches.

Official recognition of new heights depends on mapping authorities. "We do not conduct mapping surveys to determine officially recognized mountain-peaks heights," said Jason Burton, a spokesman for U.S.G.S.

Key Topics

Science, Gilbertson Brothers, Country Highpoints, East Crestone, Crestone Peak, Jabal Ferwa