De Long Islands

The De Long Islands are an uninhabited archipelago located in the Arctic Ocean. They are part of the Sakha (Yakutia) Republic in Russia. Many geographers also include them as part of the New Siberian Islands. This group of islands sits far north, near 77 degrees north latitude. The archipelago is composed of five distinct islands. These are Bennett, Henrietta, Jeannette, Zhokhov, and Vilkitsky Islands. Together, these islands cover a total area of 228 square kilometers.

Each island within the group has a different size and shape. Bennett Island is the largest of the five. It also contains the highest point in the entire archipelago, which reaches 426 meters. Zhokhov Island covers 77 square kilometers. Henrietta Island is much smaller, at 12 square kilometers. Jeannette Island covers 3.3 square kilometers. Finally, Vilkitsky Island is the smallest, measuring only 1.5 square kilometers. The islands vary in their physical features. Some rise to peaks, while others are lower lying.

The geology of the islands reveals a complex history of volcanic and sedimentary activity. Scientists have mapped several different rock types across the archipelago. These include rocks from the Early Paleozoic, Middle Paleozoic, Cretaceous, and Neogene periods. The Early Paleozoic rocks consist of Cambrian and Ordovician sedimentary rocks. These are often found mixed with small amounts of limestone. Middle Paleozoic rocks include volcanic materials like basalt, andesite, and diorite. These rocks are often folded and faulted. Cretaceous rocks are made of basalts mixed with sandstones and argillites. The youngest rocks found there are Neogene basaltic volcanic rocks.

The islands have a deep connection to the ancient Great Arctic Plain. During the Last Glacial Maximum, this plain was a large landmass called Beringia. It connected Siberia and Alaska. At that time, sea levels were 100 to 120 meters lower than they are today. The De Long Islands were once major hills within this plain. Most of the Great Arctic Plain is now submerged under the Arctic Ocean. It also lies beneath the East Siberian Sea. The islands are the remaining parts of that former subaerial plain. This plain was not heavily covered by ice during the Late Pleistocene. It sat in the rain shadow of the Northern European ice sheet.

Climate and ice play a major role in the islands' environment. The archipelago is often very cold and partially covered by glaciers. In 1996, ice caps and glaciers covered 80.6 square kilometers of the islands. Small, passive ice caps formed during the extremely frigid polar climate of the Last Glacial Maximum. Fragments of these old ice caps still exist on Jeannette, Henrietta, and Bennett Islands. Zhokhov Island is different because it is unglaciated. However, scientists found traces of former glaciers on Zhokhov. These appear as buried ground ice deposits from the Late Weichselian period.

Exploration of the islands began in the late 19th century. In 1881, George W. De Long discovered Jeannette, Henrietta, and Bennett Islands. He led the Jeannette Expedition, which was named after his ship. In 1901, the Russian ship Zarya searched the Laptev Sea for Sannikov Land. The ship became trapped in fast ice near the New Siberian Islands. During this time, explorer Baron Eduard Toll and three others vanished. They disappeared in November 1902 while traveling on ice floes near Bennett Island. Later, Boris Vilkitsky discovered the remaining two islands. He found Vilkitsky Island in 1913 and Zhokhov Island in 1914.

The islands have also been used for scientific study. Henrietta Island hosted a research station for many years. This station operated from 1937 until 1963. While the islands are uninhabited now, they have been part of political discussions. Some individuals in the United States once claimed ownership of the islands. They based this on De Long's report of taking possession of Henrietta Island. However, the U.S. government does not support this claim. The U.S. Department of State recognizes the islands as Russian territory. The islands remain an important part of the Russian Arctic landscape.