Jason Peninsula is a large peninsula on the east coast of Graham Land

Graham Land

Graham Land is that portion of the Antarctic Peninsula which lies north of a line joining Cape Jeremy and Cape Agassiz. This description of Graham Land is consistent with the 1964 agreement between the British Antarctic Place-names Committee and the US Advisory Committee on Antarctic Names, in...

 comprising several mainly snow-covered summits. It rises above Larsen Ice Shelf

Larsen Ice Shelf

The Larsen Ice Shelf is a long, fringing ice shelf in the northwest part of the Weddell Sea, extending along the east coast of Antarctic Peninsula from Cape Longing to the area just southward of Hearst Island...

 and extends from the narrow neck of land east of Medea Dome

Medea Dome

Medea Dome is a snow dome, 350 m, marking the east end of Philippi Rise on the east coast of Graham Land. Surveyed by the Falkland Islands Dependencies Survey in 1953. Named in 1956 by the United Kingdom Antarctic Place-Names Committee in association with Jason Peninsula. Medea helped Jason...

 for 42 miles, terminating in Cape Framnes

Cape Framnes

Cape Framnes is a cape which forms the northeast end of Jason Peninsula, on the east coast of Graham Land. Discovered and named in 1893 by a Norwegian expedition under C.A. Larsen. The name is probably descriptive. Larsen reported that he gave the name Framnes to the promontory which shoots off...

. This feature was first seen from seaward on December 1, 1893 by Carl Anton Larsen

Carl Anton Larsen

Carl Anton Larsen was a Norwegian Antarctic Explorer, who made important contributions to the exploration of Antarctica, the most significant being the first discovery of fossils, for which he received the Back Grant from the Royal Geographical Society...

, who named one of the high peaks Mount Jason

Mount Jason

Mount Jason is a peak just west of Bull Pass in the Olympus Range of Victoria Land. Named by the Victoria University of Wellington Antarctic Expedition for a figure in Greek mythology....

 after his ship. Larsen was too distant to map the area in detail, but in 1902 the Swedish Antarctic Expedition

Swedish Antarctic Expedition

The Swedish Antarctic Expedition was led by Otto Nordenskjöld and Carl Anton Larsen.-Background:Otto Nordenskjöld, a Swedish geologist and geographer, organized and lead a scientific expedition of the Antarctic Peninsula...

 under Otto Nordenskiöld

Otto Nordenskiöld

Nils Otto Gustaf Nordenskjöld was a Finnish and Swedish geologist, geographer, and polar explorer.-Biography:...

 observed the area from Borchgrevink Nunatak

Borchgrevink Nunatak

Borchgrevink Nunatak is a nunatak long which rises to , standing at the south side of the entrance to Richthofen Pass, on the east coast of Graham Land. It was discovered in 1902 by the Swedish Antarctic Expedition under Otto Nordenskiöld, who named it for C.E. Borchgrevink, leader of the British...

 and reported the peaks seen by Larsen to be separated from the mainland. The name Jason Island was subsequently used for Larsen's discovery, but in 1955 the Falkland Islands Dependencies Survey (FIDS) determined this feature to be a large peninsula.