Fridtjof Nansen particularly in the polar regions. The Nansen family originated in Denmark. Hans Nansen (1598–1667), a trader, was an early explorer of the White Sea region of the Arctic Ocean. In later life he settled in Copenhagen, becoming the city's "borgmester" in 1654. Later generations of the family lived in Copenhagen until the mid-18th century, when Ancher Antoni Nansen moved to Norway (then in a union with Denmark). His son, Hans Leierdahl Nansen (1764–1821), was a magistrate first in the Trondheim district, later in Jæren. After Norway's separation from Denmark in 1814, he entered national political life as the representative for
Oriental Basin the lowest part of the basin (2300 meters elevation), and remain dry for most of the year. The basin includes six maar lakes, locally called "axalpazcos", lying in shallow volcanic craters and sustained by underground water. A northern group of lakes – Alchichica, Quechulac, Atexcac, and La Preciosa – lie southeast of Lake Tepeyahualco, and the southern lakes, Aljojuca and San Miguel Tecuitlapa, lie southeast of Lake Totolcinco. The basin also has five dry maars, called "xalapazcos". Chief towns in the basin include El Carmen Tequexquitla, Tlaxcala; Perote, Veracruz; and Oriental, Puebla. Groundwater levels in the basin have been dropping