The year 2011 marks the 100th anniversary of when Roald Amundsen and his Norwegian team of adventurers were the first to reach the South Pole. The 2011 bronze marker at the South Pole honors these men. It is in the shape of a sextant, an instrument used for navigation in the Heroic Age of Exploration. There are 47 individual degree marks on both sides at the bottom of the marker, representing the number of people who wintered at the South Pole in 2010. In addition, a free-spinning "medallion" sits in between the angled arms of the bronzed sextant, which rests on a pedestal that displays the names of Amundsen's crew. On one engraved side is a well-known image of Amundsen and three other men admiring a tent flying the Norwegian flag at the South Pole. On the other is an engraving of the modern South Pole Station. Winter-over machinist Derek Aboltine fabricated the 2011 marker based on the design by fellow winter-over David Holmes.Each crew that winters over at the station designs and builds a new marker, which the following summer crew places during a ceremony to reposition the marker on January 1. The station sits on a moving ice sheet, which shifts about 10 meters, or 30 feet, each year.