De Long set out in 1879 aboard the USS Jeannette, hoping to reach Wrangel Island and to discover open seas in the Arctic Ocean near the North Pole.

At that point the party was forced to trek over the ice on foot, discovering Bennett Island during July 1881, and claiming it for the United States.

[1][2] In August 1901, Russian polar ship Zarya sailed on an expedition searching for the legendary Sannikov Land but was soon blocked by floating pack ice.

Russian explorer Baron Eduard Toll and three companions vanished forever in November 1902 while travelling away from Bennett Island towards the south on loose ice floes.

Some individuals assert American ownership of Bennett Island, and others of the De Long group, based on the 1881 landing.

[4] Bennett Island consists of Early Paleozoic, late Cretaceous, Pliocene, and Quaternary sedimentary and igneous rocks.

In 1987, the permanent ice cap of this island consisted of four separate glaciers that had a total area of 65.87 square kilometres (25.43 sq mi).

Adjacent to De Long East Glacier laid the De Long West Glacier with an area of 1.17 square kilometres (0.45 sq mi); an elevation of 330 to 340 metres (1,080 to 1,120 ft) above mean sea level; and a thickness of 40 metres (130 ft) in 1987.

According to recent studies, hydrothermal eruptions in the vicinity of the island are the cause of their formation, but this does not exclude other mechanisms of their origin, including meteorological ones.

[17] In the event of any major geothermal eruption in an ice-covered sea, it is also natural to expect a polynya to form after it ends.

The most popular theory among scientists was that the plumes were formed when clathrates—methane, trapped and frozen into a crystalline structure similar to ice by a combination of low temperatures and high pressures—melted and released methane gas.

Due to remaining cold-war tensions, and the Soviet military's desire to protect the secrecy of submarine facilities, western scientists were only able to observe the plumes remotely via satellite.

Bennett Island plumes form due to the layering of arctic air at different, very cold temperatures.

The region is relatively remote, with only warmer polynyas – open water surrounded by sea ice – to potentially provide instability.

The volume of ejected solid material reaches 0.36 km3 (0.086 cu mi), which corresponds to small volcanic eruptions.

[16] And by analogy with conventional geysers, the frequency of events is determined by the time it takes for the aforementioned hydrothermal system to restore water reserves and to warm it up for the next eruption.

Such volcanic formations are usually quickly destroyed by ocean waves or sea ice and do not remain on the surface for a long time.