Although subfossil oaks preserved in alluvial deposits represent an invaluable archive of dendrochronological information, Eastern Europe has remained largely unexplored in this regard. In this study, we investigated subfossil oak remains from the Zapadnaya Dvina (Daugava, Dzvina) River, flowing through Russia, Belarus, and Latvia. Subfossil oak trunks were collected from two sites located in the upper (near the town of Zapadnaya Dvina, Russia) and middle (the Luchosa River, Belarus) reaches of the Zapadnaya Dvina River, comprising 545 and 68 specimens, respectively. A total of 61 radiocarbon dates were obtained from both sites. The earliest subfossil oak was deposited 5800 +/- 80C years BP, while the most recent samples dates to the 20th century. Four absolutely dated tree-ring chronologies spanning 250-1762 AD were developed through dendrochronological analysis and cross-dating with oak chronologies from neighboring regions. These chronologies were further validated by wiggle-matching radiocarbon measurements of individual tree rings. In addition, six floating treering chronologies covering the 2nd and 1st millennia BC were constructed and radiocarbon dated. Together, these chronologies encompass nearly the last 4000 years, with only short gaps of up to 300 years. Continued sampling of subfossil oaks from riverine deposits in the region is expected to bridge these intervals, ultimately enabling the construction of an absolutely dated multi-millennial oak tree-ring chronology for Eastern Europe.

The spectacled cormorant, Pallas cormorant (Urile perspicillatus (Suliformes: Phalacrocoracidae)), played an important role as a source of animal protein for sailors, fur traders, and the permanent population of the Commander Islands, Russia. This endemic bird species was hunted to extinction due to human activity in the mid-19th century. Currently, there is no published genetic information available about the spectacled cormorant, and its phylogenetic relationships are primarily based on morphological traits. This study aims to address this knowledge gap by presenting two complete mitochondrial genomes from two historical specimens of this extinct species, dating back to 1510 − 1220 cal BP and 500 − 230 cal BP years, respectively. We sequenced the ancient DNA of the extinct spectacled cormorant from Bering Island in order to reconstruct its complete mitochondrial genome and determine its phylogenetic position among other extant species in the Phalacrocoracidae family. The mtDNA of the spectacled cormorant was assembled and annotated, revealing that its mitogenome is 16,895 base pairs long. It contains 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes, with an overall base composition of 32.3

Horqin was a key region in eastern Mongolia that Genghis Khan bestowed upon his brothers, Khasar and others. Around 1935, when Japan ruled Manchukuo, a unique Mongolian helmet was discovered here by Dr. Noboru Yamamoto. Though bearing a Qing prince’s name in Manchu script, the helmet’s heavy-layered iron core, gold-inlaid Lantsa mantras, and gemstones suggest earlier origins. In particular, structural analysis shows that despite its high-status symbolic features, it has a combat function. We propose it was originally Khasar’s, later modified by Horqin descendants. This rare artifact may offer valuable insight into early Mongol elite armor and prompt broader research into the material culture of the Mongol empire.

Combustion-derived magnetite has recently attracted attention for its health risks and potential impact on atmospheric heating/cooling. This study provides new observational insights into the relationship between black carbon (BC) and magnetite at a remote site in East Asia, Japan, focusing on combustion sources, seasonal trends, and potential overestimation of BC by the light-absorbing magnetite. Magnetic measurements of PM2.5 samples, complemented by detailed chemical analyses, reveal similar temporal variations between BC and magnetite while demonstrating that the relative abundance of magnetite to BC varies by combustion source, driving seasonal trends. Magnetite abundance during combustion episodes was found to follow the order: coal > oil > biomass, with mass concentrations roughly estimated via magnetization to be 9-10%, 5-6%, and <2% of BC, respectively. Furthermore, magnetite was estimated to contribute up to 5% of the BC absorption coefficient, suggesting the considerable overestimation of BC depending on the source. Although regionality and source mixing should be further verified, these findings show that magnetic measurements of archived samples can offer valuable contributions to reconstructing long-term combustion trends or overestimates in conventional observations of BC.

We present an annual-resolution, millennium-long tree-ring chronology for northern Japan. The chronology is based on 5309 measurements of tree-ring delta O-18 from 37 samples of Hiba arbor-vitae (Thujopsis dolabrata var. hondae). Although the exact geographical origin of 27 of the samples is unknown because they were extracted from excavated archaeological material, pattern matching of the tree-ring delta O-18 variations was robust among all 37 samples. The floating chronology constructed using all samples was cross-dated against a previously published delta O-18 chronology from central Japan, yielding a correlation coefficient of 0.26 (t = 9.0; p < 0.01), resulting in a temporal coverage of 417-1595 CE (i.e., 1179 yrs). The global C-14 spike event at 774-775 CE was clearly recorded in the annual C-14 data, which provides independent support for the dating of tree rings using oxygen isotopes. Furthermore, this delta 18O chronology from northern Japan was used to successfully cross-date a wood sample buried during the "Millennium Eruption" of Baitoushan, which is located on the border between China and North Korea.

We studied Holocene paleolimnological changes inferred from multi-proxy data set of CNS elements, biomarkers and microscopic observation of microalgae and cyanobacteria in sediment cores from Rundvågshetta lakes (Maruwanminami-ike and Maruwan o-ike) in the Soya Coast region of East Antarctica, along with sedimentary facies and AMS 14 C dating. They are discussed with paleoenvironmental changes, transition ages and glacio-isostatic uplift rates in the Soya Coast region and East Antarctica. Ages of the Maruwanminami-ike core (MwS4C-01, length 147 cm) and Maruwan-oike (Mw4C-01, length 226 cm) ranged from 1,230-5,010 cal BP) and 2,240-5,700 cal BP, respectively. Reservoir effects of the Rundvågshetta lakes were very high which may be due to the influence of dead carbon in glacially eroded marine sediments and base rocks. Average sedimentation rates of Lakes Maruwanminami-ike and Maruwan-oike were 0.389 and 0.649 mm/yr, respectively. Crustal uplift rates of Lakes Maruwanminami-ike and Maruwan-oike determined by sedimentary facies, green sulfur bacterial biomarkers and diatoms were estimated to be 8.24 and 8.25 mm/yr, respectively. Coastal marine environment: Maruwanminami-ike (147-72.5 cm, 5,010-2,590 cal BP) and Maruwan-oike (226-47.2 cm, 5,700-3,190 cal BP) were characterized by low biological production with the predominance of diatoms. Transition period of stratified brackish lake environment: Maruwanminami-ike (72.5-65.6 cm, 2,590-2,500 cal BP) and Maruwan-oike (47.2-28.8 cm, 3,190-2,890 cal BP) were characterized by stratified conditions with marine water overlain by freshwater, and a chemocline developed together with an anoxic layer in the bottom of photic zone. Freshwater lake environment of Maruwanminami-ike (65.6-0 cm, 2,500-1,230 cal BP) was characterized by high biological production by cyanobacteria (e.g. Leptolyngbya spp.) and green algae (e.g. Comarium clepsydra) with some contribution of diatoms, while that of Maruwan-oike (28.8-0 cm, 2,890-2,240 cal BP) was very low biological production. The marine to terrestrial transition ages of raised beaches and isolated basins in the Saya Coast region ranged from 970 to 9,290 yr BP with an average of 3,660±1,520 yr BP (standard deviation) suggesting that major warm periods in the region are the middle Holocene. Glacio-isostatic uplift rates of raised basins and isolated basins in the Soya Coast region ranged from 0.19 to 4.40 mm/yr with an average of 2.0 ± 0.92 mm/yr which is similar to East Antarctica. Glacio-isostatic uplift rates of raised beaches are correlated with altitudes with a correlation coefficient of r 2 = 0.724. Increasing crustal uplift rates with altitudes reflect continuous crustal uplifts in the Soya Coast region.

We present new data on regional correction factor (Delta R) conducted for Chukotka, the Commander Islands, and the western Aleutian Islands and summarize data previously published for the other parts of the region. Paired radiocarbon dates of coeval marine and terrestrial materials from the archaeological site Kaniskak were obtained in Chukotka, and one such pair was analyzed from Shemya Island (western Aleutians). Three samples of sea otter (Enhydra lutris) bones of known collection date were used for the Commander Islands. In conjunction with previously published data, the new results showed that Delta R estimates conducted for the five regions of the northern Pacific do not differ statistically. Delta R assessments combined for archaeological sites resulted in probability density curves of the same shape as that of marine organisms. Comparison of Delta R estimates made with various species of marine animals showed that sea otters and small fishes residing within coastal waters throughout their life histories are better suited for Delta R measurements than migrating seals, on the one hand, and the shells of sedentary organisms, on the other. The study provides additional support to the hypothesis that the northern Pacific is characterized by the same reservoir offset, which we estimate as 525 +/- 75 yr.

Cosmogenic nuclides such as 14 C from tree rings and 10 Be and 36 Cl from ice cores are excellent proxies for the past extremely large solar energetic particle (SEP) events, which are dozens of times larger than the largest SEP event in the history of observation. So far, several rapid 14 C increases have been discovered, which are considered to have originated from extreme SEP events (or set of successive SEP events) from verifications using multiple cosmogenic nuclide analyses in natural archives. Although these events are characterized by a rapid increase in cosmogenic nuclide concentrations, 14 C data recorded worldwide do not always show similar variations, especially during the 993 CE event, where a rapid increase was recorded in either 992–993 CE or 993–994 CE in several records. We present new 14 C data of the Japanese cedar sample for the 993 CE event. Although the latest data show no significant increase in 1 year, an overall increase pattern is consistent with the previously reported 14 C data of the Japanese cedar, which supports that a significant 14 C increase occurred from 993 to 994 CE in the Japanese sample. Given the dominant 14 C production in high latitudes by SEPs, the difference in timing of increase may be a transport effect in the atmosphere. Moreover, the difference in the timing of the 14 C increase can cause a 1-year age-determination error using the 993 CE radiocarbon spike. Compared with the 14 C data between tree samples from high latitude and midlatitude, including Japan, high-latitude data can capture 14 C changes originating from SEP events more quickly and clearly and may be more suitable for a SEP event exploration in the past.

ABSTRACT Tsunamis are huge disasters that can significantly damage benthic organisms and the sea-bottom environment in coastal areas. It is of great ecological importance to understand how benthic ecosystems respond to such destructive forces and how individual species are affected. Investigating the effect of such disasters on animals that are seldom caught alive is particularly difficult. Bivalve mollusks are especially suitable for investigating how a tsunami affects coastal benthic species because they preserve an environmental record in their shells that can be extended back in time by crossdating the records of multiple individuals. Here we studied dead shells of Mercenaria stimpsoni, a long-lived clam, and precisely determined the time of death by using nuclear bomb–induced radiocarbon (bomb-14C) and by counting annual growth increments. First, a quasi-continuous, regional bomb-14C record was created by analyzing the shells of 6 live-caught M. stimpsoni individuals. Then 27 dead shells collected from the seafloor of Funakoshi Bay were 14C-dated and analyzed. The results showed that the huge tsunami that struck northeastern Japan on 11 March 2011 caused mass mortality of this bivalve in Funakoshi Bay. Nine of the 27 clams died during the March 2011 tsunami, probably by starvation after burial by tsunami deposits or exposure above the seafloor as a result of sediment liquefaction during the earthquake. The dating method used in this study can help us understand how long-lived marine organisms with low population density are affected by huge natural disasters such as a tsunami.

In the late ninth century, the northern Yatsugatake volcanoes in central Japan experienced a catastrophic collapse, simultaneously causing a debris-avalanche. Such failures have been related to the AD 887 Nin'na earthquake, which occurred along the Nankai Trough. However, supportive evidence of the hypothesis remains unavailable. The present study reports wiggle match radiocarbon (C-14) dating of a buried tree excavated from a deep part of the debris deposit. The death year of the buried tree was dated as AD 838 +/- 17. The date exactly matches an inference of the AD 887 earthquake obtained from historical documents and field records of archaeological ruins, considering that C-14 ages of Japanese trees have a regional offset of approximate to 30 years greater than the IntCal dataset. Our result suggests that the AD 887 earthquake occurred along about 700 km extending from the western margin of the Nankai Trough to the central segment of the Itoigawa-Shizuoka Tectonic Line.

The 50-m-thick uppermost Pleistocene to Holocene succession exposed on Shinjima Island represents part of the sedimentary succession that was deposited in the Aira caldera. The succession was uplifted in 1780 due to magma intrusion, providing an opportunity to study post-caldera volcanism and environmental changes in the Aira caldera. The stratigraphy and origin of this succession, however, remain controversial. Based on careful revision of the classification and stratigraphic relationships of the constituent facies, here we propose the division of the succession into the Lower Shinjima Silt Bed, Shinjima Pumice, Southern Shinjima Pumice, Upper Shinjima Silt Bed, and Moeshima Shell Bed, in ascending stratigraphic order. The Lower and Upper Silt Beds are composed mainly of greenish-brown silt and contain shallow-marine fossil assemblages, representing a 100–200 m-deep inner bay environment. The Moeshima Shell Bed comprises lahar (debris and hyper-concentrated flows) deposits derived from Sakurajima volcano. The Shinjima Pumice and overlying Southern Shinjima Pumice, which are sandwiched between the Lower and Upper Silt Beds, are submarine eruption-fed density current deposits of rhyolitic composition, derived from the Wakamiko caldera over a brief interval of 12–13 cal ka BP. Tephras of known ages from the Sakurajima volcano and Yonemaru maar have been identified in the Upper Shinjima Silt Bed, and the Moeshima Shell Bed also contains pumices derived from the Sakurajima tephras. Numerous shell and wood fragments and organic particles have been collected from the Lower and Upper Sjinjima Silt Beds, Southern Shinjima Pumice, and Moeshima Shell Bed, and ages have been obtained by C dating. These chronological data suggest that the age of the Shinjima succession ranges from 13–2 cal ka BP.

Potential tsunami inundation areas can be predicted by the distribution of paleo tsunami deposits on land, which are mainly composed of marine-derived sands and muds. These exotic sandy and muddy layers have been identified by multiple approaches. However, there still remain uncertainties regarding the sources and weathering trends over the long term, and other useful proxies need to be investigated to identify of tsunami deposits. We examined the geochemical signatures of modern tsunami deposits from the Pacific coast of northeast Japan (2011 Tohoku tsunami) and those paleo tsunami deposits taken from the Tohoku District (Jogan, similar to 1080 calibrated ages before present [cal BP] and Yayoi, ca. 2000 cal BP). A geochemical ternary diagram (Seawater-Rock(As thorn Metals)) showed the weathering trends of tsunami deposits over approximately 2000 years in the Sendai plain in the Tohoku. In the tsunami layers from the Tohoku, the Na/Ti atomic ratios markedly increased to 23.4 with an average value of 19.3 +/- 3.0 (Jogan and Yayoi tsunami deposits), which was clearly higher than those of other layers (soil deposits, 10.3 +/- 3.5 on average). These results show that Na/Ti ratios and other geochemical proxies are useful indicators of marine incursions in our case, and may contribute to the detection of muddy tsunami deposits close to the limit of inundation.

To determine the variation in the rate of accumulation and chemical structure of soil organic matter (SOM) in a tropical coastal peatland, series of soil cores samples were collected in the Maludam National Park, Sarawak, Malaysia and analyzed. Duplicate soil core samples were collected from three phasic communities in the peat swamp forests, Mixed Peat Swamp (MPS; depth of 50-450 cm), Alan Batu (ABt; depth of 200-700 cm), and Alan Bunga (ABg; depth of 200-800 cm), which were located at outer, middle, and inner sites on the peat dome. The C-14 age of the SOM was determined at depths of every 50 or 100 cm and 4-6 samples from each profile were subjected to ramp cross polarization/magic angle spinning C-13 nuclear magnetic resonance (NMR) analysis. The C-14 age of SOM ranged from 1602 to 5162 years before the present (yBP), 1134-4043 yBP, and 928-3376 yBP in the cases of the MPS, ABt, and ABg forests, respectively. Those after calibration were in the ranges of 1482-5958 (MPS), 1322-4603 (ABt), and 837-3629 (ABg) yBP. The relationship between calibrated (14)C( )age and soil depth, when regressed to a linear function with the constraint that the age of surface sediment is 0 year, showed that the rate of peat accumulation was 0.60 +/- 0.01 (MPS), 1.5 +/- 0.0 (ABt), and 1.9 +/- 0.1 (ABg) mm y(-1). However, in the case of the MPS forest, this rate was not constant but decreased toward the present. The C-13 NMR results showed the decrease in the relative abundance of alkyl C and an increase in that of carbohydrate C with soil age/ depth in the MPS forest soil profiles, suggesting an acceleration in the decomposition of SOM as the cause of the decrease in the rate of accumulation of the peat. Variations in the C composition of the other two forest soils with soil age were small. The relative content of aromatic C remained relatively constant, indicating that aromatic C is consistently a major component of the C pool throughout the peat soil layers.

The Japanese nails had been produced by the traditional ironmaking way of Tatara until the Edo period since the late of 6 Century. The Tatara is characterized as the ironmaking using very fine iron sand as the resources and is distinguished from the pre-modern ironmaking way in Europe using lump iron ore. The quality of the Japanese nails is affected from steel produced by Tatara in each age. The( 14)C ages of 3 Japanese nails were measured with accelerator mass spectrometry and calibrated to calendar years. Each C-14 age provided plural calendar year periods with definite probabilities, and one of the periods determined in comparison with the history of temples and their repair records. The production ages of nails used in the Daibutuden of the Todaiji temple, the living quarters of the Manshuin temple and the Zaoudo of the Yoshino-Kinpusenji temple are before 1692, the 12 Century and before 1592, respectively, when they were repaired or reconstructed.

ABSTRACTIn our research on traditional clothing and accessories in the Ryukyu Islands of Japan, we have collected cloth fragments from traditional Ryukyuan costumes and other fabric products for radiocarbon (14C) dating. In this study, the cloth samples from historical costumes of noro priestesses (two samples), men and women from high-status families (five samples), and non-costume cloth products (seven samples), belonging to the traditional hereditary religious system of the ancient Ryukyu Kingdom, which lasted from approximately the 14th century AD to 1829 were analyzed. One extra sample originated from a silk shawl known as a Manila shawl. The oldest among the 15 samples dates back to the mid-15th century, but some newer ones belong to the unclear calibrated age range of AD 1650–1950. The measured dates are very consistent with the historical record, suggesting that acetone and acid-alkali-acid treatments are an adequate cleaning method for radiocarbon dating of silk and cotton samples produced in the late Middle Age and later.

The 4.2 ka event has attracted worldwide interest since it was suggested to be a possible cause for the collapse of ancient civilizations. With the accumulation of proxy records, however, both the nature of the 4.2 ka event itself and the manner of societal responses to climate change have become controversial. Here we present a climatic record of Daihai Lake spanning 5-3 cal ka BP, together with a cultural series for the lake basin around 4 cal ka BP, to explore the regional nature of the 4.2 ka event and the relationship between climatic variation and cultural evolution. The climatic record reflects a dry event at the interval of 4060-3690 cal yr BP that could be a regional manifestation of the 4.2 ka event. The cultural series suggests an interruption between two different cultures during the period of 4300-4000 cal yr BP. Taking into consideration the dating errors and especially the uncertainties resulting from dating cultural layers of the archaeological sections, we suggest that the cultural interruption in the Daihai Lake basin might have been caused by a monsoon-related dry event. Humans primarily engaged in agriculture likely left the lake basin because the drainage basin became unsuitable for agrarian activities as the climate became too dry, thus leaving a cultural vacancy of several centuries in the lake basin. A significant decline in the intensity of the East Asian summer monsoon on centennial to multi-decadal timescales could be associated with dramatic cooling of surface waters of both the North Atlantic and western tropical Pacific.