The island is remote and rarely visited due to the often hostile weather conditions, but is populated by penguins and seabirds, which form large breeding colonies.

The northwestern part features the younger scoria cone complex Lucifer Hill, which is surrounded by lava flows.

A vegetation community consisting of mosses and lichens grows around the fumaroles, with some members extending to non-fumarolic terrain.

[4] It is rarely visited[5] owing to the hostile weather and sea conditions,[6] and the south and southeast coasts are hardly accessible;[7] tourist vessels occasionally land on Candlemas.

[17] They are surrounded by five lava flows, the eastern of which is old and covered with volcanic ash[14] while the northern one is younger, with an irregular surface featuring blocks, ridges and gullies.

[26] Glaciers cover[23] most of the southeastern half of Candlemas,[12] an area of 4.2 square kilometres (1.6 sq mi) as of 1964[update][27] which amounts to 40% of the island.

[32] The two halves of Candlemas Island shielded the terrain from marine erosion,[3] thus allowing the growth of spits formed by boulders and shingles.

[43] A submarine ridge at 1 kilometre (0.62 mi) depth connects the group to Visokoi farther north.

[46] Both the underlying oceanic crust (8-10 million years old) and the volcanic arc appear to be young; this may explain the peculiar basalt-rich composition and small size of the volcanoes.

Phenocrysts include feldspar, olivine, plagioclase and pyroxene,[50] and there are gabbro-like xenoliths,[51] but unlike other South Sandwich volcanoes the lavas are mostly aphyric.

During the first stage, the southeastern half of the island formed, which today constitutes about 90% of the volume of Candlemas.

[57] Outcrops in cliffs of the southeastern half of the island feature alternating layers of porphyritic lava flows and scoria, which are intruded by dykes and sills and show evidence of later deformation.

[54] Apart from the lava flows, some deposits were originally emplaced in now-dry lagoons, others formed through fallout.

[26] It is possible that an earlier volcano existed at the present location of Lucifer Hill, leaving pyroclastic flow deposits in the northwestern sector of the southeastern half of Candlemas Island.

[60] Lucifer Hill consists mostly of volcanic ash mixed with scoria, with blocks reaching sizes of 15 centimetres (5.9 in).

The cones emitted numerous lava flows reaching thicknesses of 15–46 metres (49–151 ft), separated by scoria and ash eruptions.

[54] The ice of Mount Andromeda contains tephra layers produced by eruptions of Lucifer Hill.

[60] A 6,000 years old[63] tephra layer in the Vostok and South Pole ice cores has been tentatively attributed to a large explosive eruption at Candlemas,[64] which would have spread ash over a distance of 4,000 kilometres (2,500 mi).

[66] The Global Volcanism Program cites a 1250 BCE eruption recorded in ice cores, most likely from Candlemas.

[67] Five other tephra layers in the Vostok ice core, dated to 30,000, 36,500, 109,500 years ago, and 1,613 and 1,612 BCE, may have originated at Candlemas.

[69] Owing to their remote location, volcanic activity in the South Sandwich Islands is poorly documented.

[77] Carbon dioxide is the principal non-water gas emitted by the fumaroles; sulfur species are dominated by hydrogen sulfide.

[78] Temperatures underground reach 50 °C (122 °F) at 45 centimetres (18 in) depth;[15] the volcanic warmth keeps Lucifer Hill ice-free[79][30] and the lack of ice/[80] heat signature has been observed from space by satellites.

[85] Plant communities consisting of hepatics, liverworts and mosses grow around fumaroles[86] with a distinct structuration that can extend to 20 metres (66 ft) width.

[88] Similar but less well-developed communities grow on cold terrain, where various forms of lichens predominate.

[1] Dead plants have accumulated to form peat, in some places reaching thicknesses of 20 centimetres (7.9 in).

[94] One higher plant, the Antarctic hair grass, has been reported from fumarolic terrain[95] and its occurrence is restricted to these.

[105] Finds of charred bones imply that penguin populations are sometimes impacted by volcanic activity.

[109] Amphipods,[110] brittle stars[111] and echinoderms occur on the shelf around Candlemas Island,[112][113] and sea pens from somewhat deeper waters.

Larsen in 1908 landed on Shrove Point at the southeastern end of Candlemas, then by the RRS Shackleton in January 1961 and the ice patrol ship HMS Protector in March 1962 and 1964.