Impact of Submesoscale Eddies on the Transport of Suspended Matter in the Coastal Zone of Crimea Based on Drone,Satellite, and In Situ Measurement Data

Oceanology - High-resolution measurements by unmanned aerial vehicles (UAVs), satellite and in-situ data are used to study the optical structure of coastal submesoscale eddies and their influence...     

Pb–Pb Age of Carbonate Rocks of the Kamo Group,Baikit Anteclise of the Siberian Platform

Doklady Earth Sciences - The first direct Pb–Pb dating of carbonate rocks of the Kamo Group has been carried out. The Pb–Pb age of carbonates of the lower units (the Madra, Jurubchen,...     

Lithology and facies of the Burtasian and Khvalynian sediments in Manych

Results of study od the lithofacies structure of the Burtasian and Khvalynian sediments in the Manych Depression are discussed. The sediments are similar in the grain size and mineral compositions. They are mainly represented by clayey silt, as well as silty and sandy-silty clay with subangular fragments of crystalloclasts and lithoclasts. They are characterized by a low content of heavy fraction dominated by transparent minerals (apatite, garnet, biotite, chlorite, hornblende, and others). Ore minerals (limonite and magnetite) are subordinate. The Burtasian sediments are marked by thin-horizontal bedding. Bedding of the Khvalynian sediments is more diverse: horizontal, gentle-horizontal, and alternation with gentle crossbedded-diagonal (trough-like), crisscross-wavy, and other types of bedding. The lithological composition and fossil plant seeds found in the Burtasian and Khvalynian sediments make it possible to distinguish facies formed under calm (Burtasian) and calm flow (Khvalynian) hydrodynamic regimes of sedimentation in closed (lakes) and open (channels of the Khvalynian Strait) reservoirs.     

1838 Deep Carpathian Earthquake

Izvestiya, Physics of the Solid Earth - Abstract—Deep earthquakes occur in subduction zones—they play a key role in the global tectonic model. There are only a few places on the Earth...     

Oxygen Isotope Composition of Zircons from the Talnakh Economic Intrusion of the Noril’sk Province: First Data

Doklady Earth Sciences - This study presents the first results of oxygen isotope analyses (δ18O) collected on zircons from the Talnakh economic intrusion within the Noril’sk province....     

Shape of small solar system bodies

The morphometric parameters are examined for the shape of fragments of ordinary chondrites, iron meteorites, S- and C-class stony asteroids, metallic asteroids, and icy small bodies of the Solar System. All small Solar System bodies are shown to have, depending on their composition and, hence, physical and mechanical properties, a specific shape that is unique to a given composition. C-class asteroids, the strength of which is almost three times less than that of S asteroids, differ from the latter in their less elongated shape. No systematic change is observed in the morphometric parameters (increased roundness or sphericity) of small bodies of differing compositions depending on their mass, which suggests that the hypothesis of creep in small Solar System bodies is unlikely to be true. The absence of creep confirms that, regardless of their composition, all small Solar System bodies are solid elastic bodies having an ultimate strength (tensile strength and compressive strength) and a yield strength.     

Proximity to ice fields and lake depth as modulators of paleoclimate records: a regional study from southwest Yukon,Canada

Pronounced climate warming during the past century has been well documented in high-latitude regions. Nonetheless, considerable heterogeneity exists in northern climate trends. We examined the roles of cryospheric landscape and lake depth in modulating the rate and magnitude of local climate responses through a paleolimnological study of lakes from southwest Yukon, Canada. By sampling lakes at varying distances from the Wrangell-St. Elias ice fields, we hypothesized that, for lakes of similar maximum depth, sites closest to the ice fields would be relatively complacent in terms of their chironomid and diatom assemblage changes over the past ~200 years. This hypothesis is based on the moderating effect of the glaciers on local climate, which would be most pronounced in the lakes nearest to the ice fields. However, given the known ecological differences between deep and shallow lakes, we further predicted that, for a given distance from the ice fields, a sediment record from a shallower lake would show the greatest change in stratigraphic subfossil assemblages. Because of the complicated shape of the ice fields, we applied the longitude for each site (which decreases from west to east) to approximate the proximity of our study lakes to the ice fields. Consistent with our predictions, we observed a space-transgressive pattern in the chironomid assemblage turnover that was associated with their proximity to the ice fields (r = ?0.75, P = 0.034, n = 8) across lakes of similar depth (mean maximum depth ± 1, SE = 18.1 ± 2.6 m). Considering a broader network of lakes that represented a greater range in maximum depth (4.9–29 m), we found that differences in subfossil chironomid assemblages between the modern and ca. AD 1800 sediment layers were strongly related to lake depth (r = ?0.77, P < 0.001, n = 15), but failed to detect a significant relationship with latitude or longitude (i.e. our proxy for proximity to the ice fields). Similarly, our comparative high-resolution analyses of two lakes with distinct lake morphometries, but similar proximities to the ice fields, demonstrated the predicted contrasting pattern: we observed pronounced post-1880 changes in the biotic assemblages in the shallow lake and a muted and delayed response (i.e. ~1970s) in the deeper lake. Our findings confirm that cryospheric landscape features can strongly modulate regional climate. Furthermore, our work shows that investigators need to be conscious of how climate change affects the structure and functioning of lakes of different typologies, which influences the way in which paleoclimate signals are recorded and interpreted.