The peninsula occupies the north-western corner of Grande Terre and is named after Jean Loranchet, the first officer of Raymond Rallier du Baty’s second Kerguelen survey expedition in 1913.
It has a rugged, mountainous interior, with altitudes exceeding 500 m and a coastline of steep cliffs deeply incised by fjords.
As with most of Grande Terre, it is infested with introduced feral cats, rats and rabbits.
[1] The northern end of the peninsula, and the northernmost part of Grande Terre, extending northwards from the head of the Baie de la Dauphine, has been identified as a 60 km2 Important Bird Area (IBA) by BirdLife International because of its breeding seabirds.
Other birds include light-mantled albatrosses, Kerguelen terns and Eaton's pintails.