Northern Chukotka Research Articles

The History of the Discovery and Archaeological Research of the Paleo-Eskimo Site on the Wrangel Island (Northern Chukotka)

The History of the Discovery and Archaeological Research of the Paleo-Eskimo Site on the Wrangel Island (Northern Chukotka)

Environmental changes in the Eastern Arctic during the Early Gelasian Age: Palynological Data from Lake El'gygytgyn

The 2.373-2.510 Ma BP (isotopic stages 92-99; Early Gelasian Age) interval of the palynological record from Lake El'gygytgyn, northern Chukotka, includes 9 pollen zones characterizing interglacial, interstadial, and glacial plant communities. The boundaries of pollen zones and isotope stages in some cases do not correspond, indicating that the age model developed for the El'gygytgyn core requires revision. Between 2.373 and 2.510 Ma, the warmest climate occurred during MIS93, when larch forests, which included dark coniferous species, spread across the region. Alnus hirsuta (Spach) Turcz. ex Rupr., Chosenia arbutifolia (Pall.) A. K. Skvortsov, and Populus suaveolens Fish. dominated the gallery forests of the river valleys. The development of grass-shrub tundra and larch forest-tundra is associated with periods of climatic cooling, with the coolest conditions occurring at the beginning of MIS97. The consistent presence of Larix pollen throughout the Early Gelasian indicates that even in harsher climatic conditions, larch forest-tundra persisted in the areas of the Anadyr Plateau and Lake El'gygytgyn.

Evolution of Aptian and Albian magmatism of Western and Northern Chukotka (Northeast Russia) based on zircon U-Pb geochronology and rock geochemistry

ABSTRACT Across western and northern Chukotka, a region spanning 400 000 km2, we have defined three different tectono-magmatic systems that were active during the Aptian-Albian (123–100 Ma) time span: (1) the Tytylveem post-collisional belt (123–105 Ma); (2) the Chaun province of extension-related magmatism (109–100 Ma); and (3) the earliest eruptive units (106–100 Ma) of the subduction-related Okhotsk-Chukotka volcanic belt (OCVB). The observed tectono-magmatic systems are characterized by their location and by their different chemical and isotopic compositions. The general enrichment of magma sources successively increases from the OCVB to the Tytylveem belt and then to the Chaun province. While the Tytylveem belt was active, the volcanic loci shifted northwest along the strike of the belt, perhaps because of diachronous delamination of the lithosphere of the once present, but extinct, South Anyui ocean. On the scale of the entire region of NE Asia, the tectonic re-arrangement that controlled magmatism in the Early Cretaceous was marked by the extinction of major subduction zones on the periphery of the closing Oimyakon and South Anyui oceanic basins followed by magmatic events likely caused by lithospheric delamination and/or extension. Along the Pacific margin of Asia, subduction-related volcanism was nearly continuous during the entire Cretaceous.

Observations of bowhead whales along the Northern Chukotka peninsula 2010–2012 with comparisons to 1994–1996 and 2002–2005

This paper contains information on the seasonal distribution of bowhead whales (Balaena mysticetus) in coastal waters of Chukotka (northeast Russia) in 2010–2012. Data from shore-based observation posts provides spatial and temporal information about whale distribution and migration in the coastal zones, as well as information about their relative numbers. The spring migration was observed only from Uelen, Russia (66°N, 149°W), near the northwestern entrance to the Bering Strait, and extended from the end of May through the first half of June. Some year-to-year differences in numbers and migration dynamics were observed. During summer, bowhead whales were sighted in the waters of the northern coast of Chukotka Peninsula in July and August. In 2010–2012, single whales and small groups of up to 4–8 whales were observed in the area for days making non-directed movements. Our observations in 2010–2012 demonstrated that many bowhead whales visited Chukotka coast in the autumn (September) before sea ice formation. From past observations, it appears that the autumn migration begins 2–3 weeks earlier on the northwestern coast of the Chukotka Peninsula than in the (northern) entry of the Bering Strait. The autumn migration of bowhead whales began with ice formation and ended with the complete freezing of the waters. Ice conditions appear to drive high variability in timing of the bowhead autumn migration. The northeastern Chukotka coast is one of the most important feeding areas for the Bering-Chukchi-Beaufort (BCB) bowhead whale population.

Express-Diagnostics of the Water Sources of a Small Arctic River by the Results of Short-Time Hydrological Survey, Chaunskaya Lowland, Chukotka

The article gives the results of generalization of a short-time expedition hydrological–hydrochemical survey in an arctic river basin in the northeastern part of Chaunskaya Lowland in the northern Chukotka, carried out in July 2020. At a scale of a small Yanranaivaam River basin, the structure of water masses was analyzed, and the catchments of individual tributaries with intense development of cryogenic processes were identified; these processes have an effect on water chemistry, in particular, in a higher concentration of hydrocarbonate ions, dissolved ferrum, and dissolved organic carbon. Two-tracer mixing model was used to identify and evaluate the contributions of water sources and their spatial relationships at the moment of survey. The main river water sources are atmospheric waters (mostly snowmelt water), slope soil water of the seasonally thawed layer (STL), and melt water of bald-mountain ice. The dominating water source in the catchments of the middle and upper parts of the basin is atmospheric water (67–78%), and that in the catchments of the lower part of the basin is STL soil water (59–64%). River recharge by meltwater of bald-mountain ice is typical of the entire basin, and at the moment of survey it accounted for 10–14% of the total.

О жизненном пути и научной деятельности Т. С. Теина

The article presents the biographical data and the main research results of Tasyan S. Tein, archaeologist, researcher of the Laboratory of History, Archeology, and Ethnography, NEISRI. He described the main stages in the development of the ancient Eskimo culture of Northern Chukotka, reconstructed the economy and culture, researched the social structure, religious beliefs, and rituals of Eskimos. Excavations on Wrangel Island made a significant contribution to the study of the Paleo-Eskimo period. T. S. Tein obtained representative and valuable materials from the most ancient settlement of sea mammal hunters. He researched the religion and shamanism of the Asiatic Eskimos, and completed detailed descriptions of the Eskimo seasonal festivals.

Late Pleistocene to Holocene vegetation and climate changes in northwestern Chukotka (Far East Russia) deduced from lakes Ilirney and Rauchuagytgyn pollen records

This paper presents two new pollen records and quantitative climate reconstructions from northern Chukotka documenting environmental changes over the last 27.9 ka. Open tundra‐ and steppe‐like habitats dominated between 27.9 and 18.7 cal. ka BP. Betula and Alnus shrubs might have grown in sheltered microhabitats but disappeared after 18.7 cal. ka BP. Although the climate was rather harsh, local herb‐dominated communities supported herbivores as is evident by the presence of coprophilous spores in the sediments. The increase in Salix and Cyperaceae ~16.1 cal. ka BP suggests climate amelioration. Shrub Betula appeared ~15.9 cal. ka BP, and became dominant after ~15.52 cal. ka BP, whilst typical steppe communities drastically reduced. Very high presence of Botryococcus in the Lateglacial sediments reflects widespread shallow habitats, probably due to lake level increase. Shrub Alnus became common after ~13 cal. ka BP reflecting further climate amelioration. Simultaneously, herb communities gradually decreased in the vegetation reaching a minimum ~11.8 cal. ka BP. A gradual decrease of algae remains suggests a reduction of shallow‐water habitats. Shrubby and graminoid tundra was dominant ~11.8–11.1 cal. ka BP, later Salix stands significantly decreased. The forest‐tundra ecotone established in the Early Holocene, shortly after 11.1 cal. ka BP. Low contents of green algae in the Early Holocene sediments likely reflect deeper aquatic conditions. The most favourable climate conditions were between ~10.6 and 7 cal. ka BP. Vegetation became similar to the modern after ~7 cal. ka BP but Pinus pumila came to the Ilirney area at about 1.2 cal. ka BP. It is important to emphasize that the study area provided refugia for Betula and Alnus during MIS 2. It is also notable that our records do not reflect evidence of Younger Dryas cooling, which is inconsistent with some regional environmental records but in good accordance with some others.

Zircon as a Mineral Indicating the Stage of Granitoid Magmatism at Northern Chukotka, Russia

A comparative study of the zircon composition and texture in granites of a three-stage Late Cretaceous magmatism in the Chaun area, Chukotka, Russia, was conducted in biotite granites (BG), quartz monzonites-monzogranites (MG), and zinnwaldite granites (ZG). The significance of the study entails determining the mineralogical indicators of similar granitoids in areas of multi-stage petrogenesis. It is shown that in the rock series of Northern Chukotka, BG → MG → ZG, a morphological evolution of zircon takes place: a reduction in size, elongation, a growing complexity of the crystallography, and an individual texture. In later generations of zircon, as a result of the recrystallization and metasomatism, rare-metal overgrowths, defects in the crystal structure, pores and fissures, and mineral inclusions appear, whereas the crystal-face indices and patterns become more complicated. We can observe the geochemical evolution of zircon: a gradual change in the concentration of trace elements (Hf, U, Y, Th, Nb, and Ti), rare earth elements (Yb, Er, and Dy, as well as Ce and Nd), and uncommon elements (Ca and Al). Rare elements (REE, Y, Hf, Nb, U, and Th) at the post-magmatic stage of the regional history acquired economic abundances. Zircon is therefore indicative of productive ore-magmatic systems.

Warm Climatic Intervals in the Eastern Arctic during the Quaternary: Palynological Data from Lake El’gygytgyn, Northern Chukotka

Warm Climatic Intervals in the Eastern Arctic during the Quaternary: Palynological Data from Lake El’gygytgyn, Northern Chukotka

Evolution of the subsistence pattern of indigenous population of the coast of Southern Chukotka: energy and resources aspects

The aim of the research was to elucidate the changes in the subsistence patterns in Meinypilgyno village community located in the South of Chukotka on the Bering Sea coast near a spawning area of the large stock of red salmon. The research was based on modern interviews and data of the Polar Census 1926/27. The result was compared with case study of Chukchi pastoralists and Yupik communities made by Igor Krupnik (1983) in northern Chukotka. The population of Meinypilgyno was formed 90 years ago from two indigenous communities with different subsistence patterns and ecologic niches: Chukchi reindeer herders and Kereck fishermen and sea-mammal hunters. The Soviet and post-soviet economic and social reforms combined with Russian immigration changed indigenous life step by step. First, the Kereks blended in with the Chukchi community, and then the Chukchies lost their reindeer husbandry and began to merge with the Russians. Meinypilgyno became biethnic Chukchi-Russian community focused on red salmon fishing. Presently, both ethnic groups use the same ecologic niche. The analyses of the evolution of the subsistence patterns in Meinypilgyno confirms the thesis that two communities with similar subsistence activities using one ecological niche are going either to clash, or to merge together.

The Oxygen Isotope Composition of Ice Wedges of Ayon Island and Paleotemperature Reconstructions of the Late Pleistocene and Holocene of the Northern Chukotka

Syngenetic ice wedges have been investigated on Ayon Island. Their isotope composition and the geochemical characteristics of both ice wedges and enclosing sediments have been obtained; four ice-wedge stages have been distinguished. Paleo temperature reconstructions for Ayon Island and adjacent territories of northern Chukotka have been obtained based of these results. Almost identical trends in the distribution of ice-wedge isotope characteristics in the Arctic islands and in the lower reaches of the Kolyma River were observed, as well as differences in the magnitude of isotope oscillations during the transition from the Late Pleistocene to the Holocene compared to ice wedges of the Lower Kolyma region.

Oxygen isotope composition of the ice wedges of Ayon Island and Late Pleistocene and Holocene palaeotemperature reconstruction of the Northern Chukotka

Syngenetic ice wedges have been investigated in the Ayon Island. Their isotopic composition, geochemical characteristics of both ice wedges and enclosing sediment have been obtained; four ice-wedges stages have been distinguished. Paleo temperature reconstructions for Ayon Island and adjacent territories of northern Chukotka have been yielded at the basis of these results. It is observed almost identical trends in the distribution of ice-wedge isotopic characteristics in the island and in the lower reaches of the Kolyma River, as well as differences in the magnitude of isotopic oscillations during the transition from Late Pleistocene to the Holocene as compared to ice-wedges of the Lower Kolyma region.

Seasonal Movements and Relative Abundance of Bearded Seals (<i>Erignathus barbatus</i>) in the Coastal Waters of the Chukotka Peninsula

Information about bearded seal seasonal distribution in the Pacific Arctic is limited. Bearded seals (Erignathus barbatus Exleben, 1777) from coastal sites along the southern, eastern, and northern Chukotka Peninsula, Russian Federation, were observed most seasons during 1993 – 96, 1998 – 2000, 2002 – 05, and 2010 – 11. These observations provide spatial and temporal information about bearded seal seasonal distribution, movements, and relative numbers in the coastal zones. In winter, bearded seals aggregate on the young ice in the northern part of the Gulf of Anadyr. Numbers gradually increase during March. In springtime (April–May), bearded seals in the northern Gulf of Anadyr are relatively numerous around Nunligran (Cape Achen), but the number is highly variable across years. During spring bearded seals move eastward along the coast from the northern part of the Gulf of Anadyr towards the Bering Strait and then to the north, as the marginal ice edge zone retreats north. These movements to the east and north continue in ice-free water, and by August, the spring migration of bearded seals along the coast of the Chukotka Peninsula ends. In the summer months of August and September, few bearded seals are present in this coastal zone. The southward autumn migration of bearded seals is not evident near the coast, which suggests that it occurs farther from shore.

Trends in sea-ice cover within bowhead whale habitats in the Pacific Arctic

The range of the Bering-Chukchi-Beaufort (BCB) population of bowhead whales (Balaena mysticetus) extends across the seasonally ice-covered waters of the Pacific Arctic region. The majority of whales summer in the eastern Beaufort Sea and winter in the Bering Sea, migrating across the Chukchi Sea in fall and spring. As arctic sea-ice extent rapidly diminishes, the increasing length and variability of the open water season is changing bowhead habitat substantially, with many areas now regularly ice-free when whales are present. This study examines changes in the number of open water days (OWD) between 1979 and 2014 within annual bowhead whale core-use areas as defined by satellite tagging data, and within the western Beaufort Sea (140–157°W; to 72°N) sampled by fall aerial surveys. Ice cover has decreased more in the core-use areas in the northern extent of the range than in core-use areas in the southern extent. The numbers of OWD within the core-use areas near Point Barrow and along the northern Chukotka Coast during peak use have increased by 13 and 10 days/decade, respectively. The most dramatic reductions in sea-ice cover have taken place in the western Beaufort Sea where the number of OWD on the shelf and slope have increased by 20 and 25 days/decade, respectively. In contrast, sea-ice cover has not significantly changed within the winter core-use area near the Gulf of Anadyr. Using aerial survey data, we found that bowheads in the Beaufort Sea during the fall migration have a preference for being closer to shore than to the ice edge, and that their distance to shore decreases as the fraction of open water increases. This distribution may be due to increased feeding opportunities closer to shore as a result of greater upwelling along the shelf break when the ice cover is farther from shore. Furthermore, the aerial survey data also revealed a substantial shift westward toward Point Barrow in the whales’ use of the western Beaufort Sea during fall in the period 1997–2014 compared to 1982–1996. The extent and timing of sea-ice coverage has changed relatively little over time in the Bering Sea. Bowheads typically migrate north prior to spring ice melt and retreat; therefore, large changes in the timing of the spring migration are not expected. We anticipate that bowheads will spend increasingly more time within summer and fall feeding areas, delaying their arrival to wintering areas in the Bering Sea. Reduced ice coverage and thickness in the southern Chukchi Sea may make wintering there more common in the future. Summer and fall movements may be more variable as productivity and zooplankton aggregations in existing feeding areas are altered in response to sea ice thinning and retreat, and as new areas become available.

Trace element and isotopic geochemistry of Cretaceous magmatism in NE Asia: Spatial zonation, temporal evolution, and tectonic controls

Results of a comprehensive geochemical study (major and trace elements, and isotopes of Sr, Nd, Pb, Hf) of Cretaceous volcanic rocks from the Chukotka area in northeastern Russia are presented. Synthesis of available geological and geochronological data suggests diachronous onset of activity of the Okhotsk–Chukotka volcanic belt (OCVB), the largest magmatic province in the region. The OCVB consists of ca. 106km3 of volcanic rocks. At 106–105Ma, subduction-related magmatism initiated in the southern and central segments of the OCVB. In the Central and Northern Chukotka areas, where the northern OCVB is exposed, onset of arc magmatism occurred ca. 10m.y. after extension-related magmatism of the Chaun igneous province at 109–104Ma. Mafic rocks from the OCVB yield (87Sr/86Sr)80Ma of 0.7033 to 0.7047, εNd80Ma of 0.0 to 7.10, εHf80Ma of 4.12 to 12.88, (206Pb/204Pb)80Ma of 18.11 to 18.42, and (208Pb/204Pb)80Ma of 37.96 to 38.21. Volcanic rocks from the Chaun province, as well as OCVB rocks from Northern Chukotka, originate from a relatively enriched source and have (87Sr/86Sr)80Ma of 0.7088 to 0.7100, εNd80Ma of −5.81 to −3.42, εHf80Ma of −3.40 to −0.25, (206Pb/204Pb)80Ma of 18.69 to 18.90, and (208Pb/204Pb)80Ma of 38.65 to 38.86. No definitive across-arc elemental or isotopic zonation of the OCVB has been revealed, probably because of wide-scale crustal melting and subsequent contamination of mantle-derived melts. However, there is a clear along-arc isotopic zonation. In our interpretation, this results from heterogeneity of the subcontinental lithospheric mantle, which likely was a major contributor to the magma source. The similar isotopic signatures of silicic (dominantly crust-derived) and mafic (mantle-derived) volcanic rocks in each OCVB segment imply that remelting of juvenile mafic underplated material was the main process responsible for the crust-derived magma generation. These data from the major Cretaceous magmatic provinces of northeast Asia are synthesized in context of existing plate tectonic reconstructions.

Features of ore formation in the gold-quartz Sovinoye deposit (Northern Chukotka)

The results of studying fluid inclusions in the quartz of ore body no. 6 from the Sovinoye deposit developed by the underground mine workings at a depth of 80 m from the surface are considered. The investigations showed that the ore in the Sovinoye deposit was formed at average temperatures during several stages from weakly concentrated hydrotherms saturated with Na, Cl, Mg, and Fe ions. Such ore-forming conditions are typical of mezothermal gold-quartz veined deposits in the terrigeneous quartz-carbonate strata. The results of FI study by modern methods do not contradict the previously offered metamorphogenic-magmatogenic model of ore formation for the Sovinoye deposit.

Late Quaternary vegetation of Chukotka (Northeast Russia), implications for Glacial and Holocene environments of Beringia

Two lake records from the Kankaren region of southern Chukotka, when combined with other palynological and macrofossil data, document spatial and temporal variations in the regional vegetation history since ∼21,000 14C/25,400 cal yr BP. Full-glacial environments were severely cold and arid in central and northern Chukotka, whereas southern sites experienced conditions that were relatively moist, although still drier than present. Southern Chukotka may represent a western extension of environments of the land bridge proper, including a possible “moisture” barrier to intercontinental migration. Shrub Betula tundra established earliest in southern Chukotka (∼15,800–14,000 14C/19,000–16,700 cal yr BP; ∼13,000 14C/15,300 cal yr BP central and north), Pinus pumila earliest in the north (∼9600 14C/11,100 cal yr BP; ∼7600 14C/8400 cal yr BP south), and shrub Alnus earliest in both the south and north (∼12,000–11,000 14C/13,800–12,900 cal yr BP). These patterns support the presence of cryptic refugia for Betula and Alnus in Chukotka during the full glaciation. In contrast, P. pumila probably migrated into Chukotka from populations located in the northern coastal lowlands and from mountainous regions of southwestern Beringia. Evidence for a thermal optimum (∼11,000–8000 14C/12,900–9000 cal yr BP) is strong in northern Chukotka but is absent in central and southern areas.

Monitoring of persistent organic pollutants in the ambient air as an element of implementation of the Stockholm Convention on persistent organic pollutants

The results of monitoring of persistent organic pollutants (POPs) in the atmosphere of the Russian Arctic are presented. The concentrations of POPs in different regions of the Russian and foreign Arctic are compared. It was revealed that the concentrations of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) are higher in the Northern Chukotka (Valkarkai) as compared to that at the other Russian stations (Amderma and Dunay) and foreign global POPs monitoring stations. The composition of PCB congeners in the air of the Arctic Chukotka turned out to be different from that observed at the other monitoring stations, being similar to commercial PCBs mixtures. In contrast to observations at most of the global POPs monitoring stations, monitoring in the Far East Russian Arctic has revealed increased levels of PCBs in the air for the last 6–8 years. The levels of DDT in the past 6–8 years have remained virtually unchanged, whereas those hexachlorocyclohexane have decreased somewhat. It was shown that polybrominated diphenyl ethers (PBDEs) are ubiquitous and are found in significant quantities in the air in both the central cities (Moscow, Obninsk) and remote locations (Arkhangelsk, Amderma, Valkarkai). The gas phase contains largely more volatile low-brominated DEs, while atmospheric aerosols contain predominantly highly brominated congeners. The indoor air at all sampling locations contained substantially higher concentrations of PBDEs as compared to the atmospheric air. Priorities for the establishment of a national system for monitoring of POPs within the framework of the Stockholm Convention on POPs control are proposed.

Population decline in the spoon-billed sandpiper (Eurynorhynchus pygmeus) in northern Chukotka based on monitoring on breeding grounds

The spoon-billed sandpiper is endemic of the northern Russian Far East and one of the rarest wader species in the world. During a field survey (summer 2002) of the coast of Kolyuchinskaya Bay and in lagoons located to the east, it was discovered that the species breeding population has declined by 3–5 times since the 1970s and amounted to only 42–50 breeding pairs. The reasons for this decline are uncertain. They seem to occur outside the breeding grounds, on staging or wintering areas in South Eastern Asia. The breeding productivity of the spoon-billed sandpiper is relatively low, but it did not decrease in recent decades. The breeding success in 2002 was higher than in the 1980s; however, it was still about half of the minimum level necessary to keep the local breeding population stable. Annual survival of the spoon-billed sandpiper is about 5–15% lower than in several other small Calidridinae waders. An increased mortality rather than decreased productivity appears to be responsible for the general decline of the spoon-billed sandpiper population. In the early 2000s, its total world population was estimated at 350–500 breeding pairs. The estimate of the spoonbilled sandpiper population obtained by Flint and Kondratyev (1977) is likely an overestimate.

Fall and Winter Movements of Bowhead Whales (<i>Balaena mysticetus</i>) in the Chukchi Sea and Within a Potential Petroleum Development Area

Working with subsistence whale hunters, we tagged 19 mostly immature bowhead whales (Balaena mysticetus) with satellite-linked transmitters between May 2006 and September 2008 and documented their movements in the Chukchi Sea from late August through December. From Point Barrow, Alaska, most whales moved west through the Chukchi Sea between 71˚ and 74˚ N latitude; nine whales crossed in six to nine days. Three whales returned to Point Barrow for 13 to 33 days, two after traveling 300 km west and one after traveling ~725 km west to Wrangel Island, Russia; two then crossed the Chukchi Sea again while the other was the only whale to travel south along the Alaskan side of the Chukchi Sea. Seven whales spent from one to 21 days near Wrangel Island before moving south to northern Chukotka. Whales spent an average of 59 days following the Chukotka coast southeastward. Kernel density analysis identified Point Barrow, Wrangel Island, and the northern coast of Chukotka as areas of greater use by bowhead whales that might be important for feeding. All whales traveled through a potential petroleum development area at least once. Most whales crossed the development area in less than a week; however, one whale remained there for 30 days.