The origin and age of driftwood on Jan Mayen

Abstract

Analysis of the wood anatomy of 481 driftwood specimens from Jan Mayen shows that Larix spp. constitute approximately 70% of the trees, while sawn logs are dominated by Pinus spp. by approximately 69%. A total of 356 driftwood samples from Jan Mayen and a small number of samples from Bjørnøya in the Barents Sea and the Troynoy Island in the Kara Sea were analysed by dendrochronological methods. A driftwood Pinus chronology was dated absolutely using chronologies from living trees of Pinus sylvestris in the lower proximity of the Angara River, a tributary of the Yenisey in Siberia. About 27% of the pine logs measured on Jan Mayen were found to originate in the same region, with end years concentrated in the 1940s and 1950s. A similar source was also found for Pinus driftwood logs on Bjørnøya and Troynoy. The results confirm and further delimit the source areas of the Yenisey driftwood established earlier from driftwood logs on Svalbard and Iceland. A subordinate source of both Pinus and Picea logs on Jan Mayen is northwest Russia, from the Kola Peninsula to the Pechora River. The Transpolar Drift Stream is believed to be the main distributor of driftwood from Siberian and northwest Russian sources to Jan Mayen, via the East Greenland Current. Dendrochronological dating reveals a strong, continuous input of ice-rafted driftwood from the Kara Sea. Radiocarbon datings from Jan Mayen show surface deposits of driftwood to be less than 500 years old, due mainly to extensive degradation of older wood and little or no land uplift.