Stratigraphic evidence and extensive optically stimulated luminescence (OSL) geochronology from an 18-km-long reach of the middle Rangitata Valley, South Island, New Zealand, provide evidence for at least six distinct glacial advances during the last glacial cycle. These include four well-constrained Marine Oxygen Isotope Stage (MIS) 3 and 2 advances at ca. 38 ka, ca. 27 ka, ca. 21 ka and at 18 ka, as well as less well-constrained advances in MIS 4 and/or early MIS 3. Ice occupied a farther downvalley reach of the Rangitata from 38 ka to after 18 ka, indicating that near-full glacial conditions persisted for most of the last 20 ka of the last glaciation, though the glacier still fluctuated significantly, as reflected by the numerous distinguishable advances. Global or regional cooling alone cannot explain the persistence of near-maximum glacial conditions for this extended period, nor can it explain the occurrence of the largest advances ca. 32 ka. Instead, we invoke the northward expansion of the westerlies during MIS 3 as the cause for the early widespread glaciation, wherein enhanced westerly flow under moderate cooling maximised glacial extents. Local insolation favoured extended MIS 3 glaciation until ca. 32 ka. Increasing summer insolation gradually reduced glacial extents after ca. 28 ka.

We report on strontium (87Sr/86Sr) isotope results from 91 modern trees growing on the Bahamas and Turks and Caicos Islands. The average 87Sr/86Sr ratio of 0.709169±0.000010 is consistent with the late Quaternary limestone of the islands and with the modern ocean value. The absence of any detectable influence of 87Sr-enriched Saharan dust is notable, given the known contribution of this material to both past and recent soils of the Caribbean. Our results indicate that the impact of Saharan dust to the modern biosphere of the Bahamian archipelago is at least an order of magnitude less than modeled in currently available strontium isoscapes for the circum-Caribbean. We suggest that the bioavailability of Sr in Saharan dust may be considerably less than previously thought. Nevertheless, further work could usefully be carried out in the Bahamian archipelago on plants with different rooting depths, growing on different soil types and on limestone of different ages. Our results have particular relevance for the refinement of existing strontium isoscapes and the archaeological provenience of artifacts, animals, and people in the circum-Caribbean.

Relic archeological settlement is used to indicate the development of agriculture. We extracted 8865 relic archeological settlements from the Atlas of Chinese Cultural Relics to analyze how the spatiotemporal distribution of archaeological settlements was influenced by temperature changes and social factors during the last millennium. During the Liao dynasty (AD 916–1125) and Jin dynasty (AD 1115–1234) in the Medieval Warm Period (MWP), a large number of settlements indicated the development of agriculture as far north as 47°N. The warm climate of the MWP provided sufficient heat resources to promote the implication of positive policies of the Liao and Jin dynasties to develop agriculture and settlements. By contrast, during the dynasties of Yuan (AD 1279–1368), Ming (AD 1368–1644), and Qing (AD 1644–1911) in the Little Ice Age (LIA), the number of settlements declined drastically, and the northern boundary of the settlement distribution retreated by 3–4 degrees of latitude to modern Liaoning Province. Although the southward retreat of the settlements and related agriculture occurred in the cold climate of the LIA, it could not be completely explained by the drop in temperature. Social factors including nomadic customs, ethnic policies, and postal road systems played more important roles to the northern boundaries of the settlement distributions during the Yuan, Ming, and Qing dynasties.

Identifying climates favoring extreme weather phenomena is a primary aim of paleoclimate and paleohydrological research. Here, we present a well-dated, late Holocene Dead Sea sediment record of debris flows covering 3.3 to 1.9 cal ka BP. Twenty-three graded layers deposited in shallow waters near the western Dead Sea shore were identified by microfacies analysis. These layers represent distal subaquatic deposits of debris flows triggered by torrential rainstorms over the adjacent western Dead Sea escarpment. Modern debris flows on this escarpment are induced by rare rainstorms with intensities exceeding >30 mm h−1 for at least one hour and originate primarily from the Active Red Sea Trough synoptic pattern. The observed late Holocene clustering of such debris flows during a regional drought indicates an increased influence of Active Red Sea Troughs resulting from a shift in synoptic atmospheric circulation patterns. This shift likely decreased the passages of eastern Mediterranean cyclones, leading to drier conditions, but favored rainstorms triggered by the Active Red Sea Trough. This is in accord with present-day meteorological data showing an increased frequency of torrential rainstorms in regions of drier climate. Hence, this study provides conclusive evidence for a shift in synoptic atmospheric circulation patterns during a late Holocene drought.

The population size of anadromous salmon in the Pacific Northwest is strongly influenced by decadal variation in watershed and oceanographic conditions and therefore should also be influenced by larger magnitude millennial-scale variations in these conditions. We studied δ15N of bulk organic matter in lake sediment from Woahink Lake, Oregon, as a proxy of marine-derived nutrients (MDN) from spawning coho salmon. We compared this site to a control lake with a natural barrier to salmon migration. From 7.5 to 5.4 ka, a dune was emplaced, breached, and emplaced again, forming Woahink Lake in a former estuary. δ15N decreased steadily since 5.4 ka at Woahink but not at the control lake. δ15N reached a minimum just prior to anthropogenic nutrient loading, which caused an increase in δ15N, thus precluding a comparison with the historical decline in salmon abundance. A mixing model of lake-water nitrate, developed to explore alternate scenarios for the observed range of δ15N, could not explain these results without invoking MDN input from at least several hundred salmon annually. Our results show a previously unreported pattern of a millennial-scale decline in salmon that has plausible linkages to parallel changes in ocean circulation and productivity.

In north-central China, subsistence practices transitioned from hunting and gathering to millet-based agriculture between the early and middle Holocene. To better understand how ancient environmental changes influenced this shift in subsistence strategies and human activities at regional to local levels, we conducted palynological and lithologic analyses on radiocarbon-dated sediment cores from the Luoyang Basin, western Henan Province. Our palynological results suggest that vegetation shifted from broad-leaved deciduous forest (9230–8850 cal yr BP) to steppe-meadow vegetation (8850–7550 cal yr BP), and then to steppe with sparse trees (7550–6920 cal yr BP). Lithologic analyses also indicate that the stabilization of the Luoyang Basin’s floodplain after ~8370 cal yr BP might have attracted people to move into the basin, promoting the emergence of millet-based agriculture during the Peiligang culture period (8500–7000 cal yr BP). Once agricultural practices emerged, the climatic optimum after ~7550 cal yr BP likely facilitated the expansion of the Yangshao culture (7000–5000 cal yr BP) in north-central China. As agriculture intensified, pollen taxa related to human disturbance, such as Urtica, increased in abundance.

The Berelyokh site includes an exceptional bone horizon consisting of 8431 remains of Mammuthus primigenius. Previous investigations, spanning ~40 years, concluded that the deaths and bone concentration were caused by spring flooding, possibly related to wetter Bølling climates. We review work from these studies with emphasis on under-reported palynological data to provide more detail on paleoenvironmental reconstructions and an alternative interpretation for the age and origin of the bone bed. Palynological results suggest the horizon formed under cool conditions of the last glacial maximum, rather than during a Bølling-type oscillation. Presence of permafrost features and associated tundra pollen taxa in the Berelyokh sections suggest that thermokarst processes, unrelated to climate change, could account for the formation of the bone horizon. The penetration of surface waters into frozen sediments of a high floodplain terrace resulted in the formation of hidden thaw sinks. As thaw continued, the pits expanded with surface soils supported by a viscous water-sediment mixture. The weakened surface gave way under the weight of the mammoths, with the hillside collapsing either due to the animals’ struggles or destabilization related to the thaw sinks. This scenario highlights the hazards of thermokarst terrain for present and future populations of northern animals.

Geomorphic analysis and optically stimulated luminescence (OSL) ages from undated Lake Agassiz beaches and adjacent fluvial sediments on Riding Mountain in Manitoba provide insight into their early history. New OSL ages of 14.5±2.4 and 13.4±0.7 ka on the oldest (Herman to Norcross) beaches of Lake Agassiz near the Canada-U.S. border indicate that the Laurentide Ice Sheet (LIS) retreated from that part of the Agassiz basin by ~14.5 ka. To the north along Riding Mountain, the Herman strandlines are absent, and OSL ages on the oldest beach there average 12.9 ka, which links it to the younger Norcross-Tintah strandlines. In adjacent Riding Mountain, OSL ages and geomorphological relationships of a large abandoned glacial spillway >200 m above the oldest beaches of Lake Agassiz indicate that this channel predates retreat of the LIS and formation of beaches in this part of the Agassiz basin, with ice remaining in this area until after 14.5 ka. OSL ages on the Gimli beach 170 km to the east are >3000 yr older than conventional assignments, suggesting that it formed during the Moorhead low-water phase 12.8–10.6 ka. Luminescence ages support the conclusion that the Campbell beach formed ~10.9 ka near the end of the Moorhead low-water phase.

Glacial extent mapping and dating indicate that the local last glacial maximum (LLGM) of the northeastern Tibetan Plateau occurred during mid-Marine Isotope Stage (MIS) 3. This is asynchronous with the global last glacial maximum (LGM) that occurred during MIS 2. The causes underlying this asynchronicity are the subject of ongoing debate, and paleoclimatic reconstructions are a key to advancing understanding of the climatic influence on the spatial and temporal patterns of paleoglaciation. We used multiple methods to reconstruct the equilibrium-line altitude (ELA) of the Die Shan paleo-ice cap on the northeastern Tibetan Plateau, and to infer past temperature for ice maximum positions believed to be mid-MIS 3 in age, based on regional correlation. Geomorphic ELA reconstructions combined with an energy and mass balance model yield a paleo-ELA of 4117±31 m asl (786 m lower than present) with temperature depressions of 3.8 to ~4.6°C compared to the present. This is less than the LGM reconstruction of temperature depression inferred from other climatic proxy records on the Tibetan Plateau and suggests that the LLGM glacial advance was a product of lower temperatures and slightly reduced precipitation compared to present, whereas the LGM was a more restricted advance in which much colder conditions were combined with much lower precipitation.

To understand past and future sea-level variability, it is important to know if during an interglacial the eustatic sea level is constant or oscillates by several meters around an average value. Several field sites within and outside the tropics have been interpreted to suggest such oscillations during Marine Oxygen Isotope Stage (MIS) 5e (129–116 ka). Here, we present our analysis of one such non-tropical site, Hergla, where a facies succession indicates two foreshore deposits above each other, previously interpreted as MIS 5e sea-level highstand amplified by a second rise. Our study, based on field, microfacies, and optical age Bayesian statistics shows a sea-level rise forming the upper foreshore strata that coincided with the global sea-level rise of the MIS 5a interstadial. The site does therefore not provide evidence for the MIS 5e double peak. We conclude from our analysis that the facies-based proxy is insensitive to small-scale sea-level oscillation. Likewise, uncertainties associated with age estimates are too large to robustly infer a short-term sea-level change.

High-precision concentrations of chlorite minerals from the Lingtai section in the Chinese Loess Plateau and the surrounding deserts are presented through a mineral liberation analyzer technique. Variations in chlorite concentration over the last 0.5 Ma display a typical pattern of glacial–interglacial changes, with its bulk content in loess units approximately twice that in paleosol units. This climate-driven chlorite change is more pronounced in the fine-size fraction (5–20 μm) of the loess deposits. Evidence from changes in hornblende and muscovite along the same profile suggests that the glacial–interglacial oscillations were likely controlled by changes in atmospheric circulation and shifts in the dust provenance instead of postdepositional weathering. A relatively high chlorite content in several deserts near Mt. Qilian compared with the other desert basins suggests that a transport pathway in the west–east direction, associated with southward shifts of the winter monsoons, may play an important role in modulating the chlorite records. In addition, enhanced saltation and transportation of dust materials is thought to be a main driver of the pronounced changes in the fine-size fraction. Finally, we discuss a possible forcing mechanism behind different long-term trends between the chlorite and its secondary weathering products we observed here.

We present the first tephroanalysis based on geochemical fingerprinting of volcanic glass shards from eastern Apulian shelf sediments in the Gulf of Taranto (Italy). High sedimentation rates in the gulf are ideal for high-resolution paleoclimate studies, which rely on accurate age models. Cryptotephrostratigraphy is a novel tool for the age assessment of marine sediment cores in the absence of discrete tephra layers. High-resolution quantitative analysis of glass shard abundance in the uppermost 45 cm of a gravity core identified two cryptotephras. Microprobe analysis of glass shards supported by an accelerator mass spectrometry 14C–based age model identified the pronounced primary cryptotephra at 36 cm bsf (below sea floor) as the felsic AD 776 Monte Pilato Eruption on the island of Lipari, whereas the thinner, mafic tephra layer at 1.5 cm bsf is associated with the AD 1944 eruption of Somma-Vesuvius. Identifying these tephra layers provides an additional, 14C-independent, stratigraphic framework for further paleoclimatic studies allowing us to link Mediterranean climate and hydrology to orbital variation and large-scale atmospheric processes. Our results underline the importance of qualitative tephrostratigraphy in a highly geodynamic region, where solely quantitative approaches have demonstrated to bear a high potential for false correlations between tephra layers and eruptions.

The Arda River marine succession (Italy) is an excellent site to apply an integrated approach to paleoenvironmental reconstructions, combining the results of sedimentology, body fossil paleontology, and ichnology to unravel the sedimentary evolution of a complex marine setting in the frame of early Pleistocene climate change and tectonic activity. The succession represents a subaqueous extension of a fluvial system, originated during phases of advance of fan deltas affected by high-density flows triggered by river floods, and overlain by continental conglomerates, indicating a relative sea level fall and the establishment of a continental environment. An overall regressive trend is observed through the section, from prodelta to delta front and intertidal settings. The hydrodynamic energy and the sedimentation rate are not constant through the section, but they are influenced by hyperpycnal flows, whose sediments were mainly supplied by an increase in Apennine uplift and erosion, especially after 1.80 Ma. The Arda section documents the same evolutionary history of coeval successions in the Paleo-Adriatic region, as well as the climatic changes of the early Pleistocene. The different approaches used complement quite well one another, giving strength and robustness to the obtained results.