Composition of airborne material from yellow snow fallen in the Russian North

Large amounts of dust responsible for bright colors of atmospheric precipitation in the temperate, subpolar and polar zones of the northern hemisphere have been rarely observed. In the twentieth century and in the beginning of the twenty first century in the Northern European Russia such events were not registered up to March 25-26, 2008. At that time in some parts of the Arkhangel'sk region, Komi Republic, and Nenets Autonomous Area atmospheric precipitation as sleet and rain responsible for sand- and saffron colors of ice crust formation on the snow surface was observed. During detailed mineralogical, geochemical, pollen, diatom and meteorological investigations it was established that semidesert and steppe regions of the Northwest Kazakhstan, Volgograd and Astrakhan' regions, and Kalmykia are the main sources of the yellow dust.

Physical properties and age determination of sediment cores from the Hinlopen/Yermak Megaslide north of Spitsbergen, Arctic Ocean

Integrated interpretation of multi-beam bathymetric, sediment-penetrating acoustic (PARASOUND) and seismic data show a multiple slope failure on the northern European continental margin, north of Spitsbergen. The first slide event occurred during MIS 3 around 30 cal. ka BP and was characterised by highly dynamic and rapid evacuation of ca. 1250 km**3 of sediment from the lower to the upper part of the continental slope. During this event, headwalls up to 1600 m high were created and ca. 1150 km**3 material from hemi-pelagic sediments and from the lower pre-existing trough mouth fan has been entrained and transported into the semi-enclosed Sophia Basin. This megaslide event was followed by a secondary evacuation of material to the Nansen Basin by funnelling of the debris through the channel between Polarstern Seamount and the adjacent continental slope. The main slide debris is overlain by a set of fining-upward sequences as evidence for the associated suspension cloud and following minor failure events. Subsequent adjustment of the eastern headwalls led to failure of rather soft sediments and creation of smaller debris flows that followed the main slide surficial topography. Discharge of the Hinlopen ice stream during the Last Glacial Maximum and the following deglaciation draped the central headwalls and created a fan deposit of glacigenic debris flows.