The study is based on CTD measurements collected during Arctic cruises in Isfjorden including Billefjorden and Gronfjorden in summer between 2011 and 2017. The purpose of this paper is to describe the present state of fjords water masses. In the first part of the paper distributions of water masses in Isfjorden and Billefjorden in summer 2014–2017 and in Grönfjorden in summer 2011– 2017 are analyzed. In paper was shown that for Isfjorden and Grönfjorden there were 4 types of masses: surface water, intermediate water, transformed Atlantic water, and Atlantic water. In June 2014, was recorded the situation when Atlantic waters occupied the entire water area of Isfjord and Grönfjord. In summer in Billefjorden were identified 4 types of masses: surface water, intermediate water, local water, and winter water. In Isfjorden, new maximum temperature of Atlantic water was observed (6.85 °С) in summer 2016. It is greater on almost 0.5 °С than previous warmest peak in 2006. The maximum average values of water temperature, heat content in the upper 40 m layer were recorded in 2016. The summer 2016 was the warmest in Isfjorden, Billefjorden and Grönfjorden during the survey period.

Summary We present a case study of the dayside aurora observed simultaneously with optical instruments from the ground and with auroral particle spectrometers aboard the DMSP F16 and F17 satellites. Optical observations were carried out with an all-sky camera at the Polar Geophysical Institute (PGI) observatory Barentsburg on Svalbard. The aurora as a whole moved equatorward in response to negative turning of the IMF Bz component and then the distinct faint rayed arc intensified, moved to the north and faded. Satellite DMSP F17 crossed the cusp twenty minutes after Bz turned southward. Joint analysis of optical and satellite data showed that faint auroral structures are embedded into the cusp precipitations and correspond to the bursts of electron precipitations with energy below 100 eV. The next satellite crossed the camera field-of-view ten minutes later and the data showed that the source of the faded poleward moving rayed arc was located, most probably, on the non-closed magnetic field lines. This finding and the presence of ion-energy dispersion in the DMSP data allows us to make the conclusion that the dayside reconnection may be considered as the reason for this kind of aurora activity. In this study we also estimated the altitude and horizontal scale of auroral rays in the cusp.

In last two decade, studies of ice ridge morphometry and strength properties have been actively carried out. Thermal drilling of ice and experiments to determine the local strength of ice using a borehole jack are performed. The paper discusses the issues of joint use of thermal drilling equipment and borehole jack for the ice cover research. Two approaches to the comparison of the results obtained by these two methods are considered. Average penetration rate versus local ice strength dependences are presented. With increasing ice strength and decreasing penetration rate the interval of changes in the ice strength increases and correspondence of the strength to the penetration rate decreases. Based on the results of ice ridges research, depth-wise distributions of local strength and thermal drill penetration rate are compared. Difference between the average thicknesses of the consolidated layer obtained from these distributions was 5 %.

In November 2016 a seismic station “Severnaya Zemlya“ with code SVZ was installed on the Severnaya Zemlya archipelago (Bolshevik island, research facility “Ice base “Baranov’s cape”) by joint efforts N. Laverov Federal Center for Integrated Arctic Research (Arkhangelsk) and Arctic and Antarctic Research Institute (St. Petersburg). This station was included in the Arkhangelsk seismic network and a broadband set of CMG-6TD devices (Great Britain) was installed there.

The microseismic background is characterized by a low level of industrial noise which allows to obtain the high-quality seismic information. Over 400 regional earthquakes and 25 local seismic events were recorded by seismic station SVZ within period from November 2016 to December 2017. Processing of regional earthquakes was carried out by us according to the data of at least three stations. We used wave forms from the Arctic stations of the Arkhangelsk seismic network and/or other seismological networks, whose stations are installed in the Arctic. In general, the majority of seismic events occur at epicentral distances of 3.5°–4° (i.e., they are regional) and associated with Gakkel Ridge. The strongest earthquakes are recorded from the areas of the Knipovich Ridge and Spitsbergen. Regional earthquakes magnitude range recorded by the SVZ is from 3.1 to 5.4. ML = 2.5 — it is the value of the magnitude from which the station registers earthquakes in full range. Local earthquakes magnitude range is from 1.2 to 4.9. Weak earthquakes with МL < 2.5 predominate.

The difficulty is that out of the total number of regional and local events registered by SVZ only part of them could be processed according to the standard seismic rule (at least 3 stations). These events were included in the Seismic Catalogue. The predominant numbers of earthquakes are recorded only by SVZ station and they can not be included in the Seismic Catalogue due to the low quality data processing seeing that only one station was used. However, even in the first approximation these  epicenters are confined to Eastern part of Gakkel Ridge, the boundary of the Kara plate and fall into the zone of the North Taimyr deformation associated with tectonic fault. Seismicity around Severnaya Zemlya to all appearance associated with an indirect reflection of rifting processes emerging in the central seismically active zone of the Laptev Sea. The calculation of earthquakes focal mechanisms recorded by SVZ is currently not possible due to the practical absence of seismic stations in the region. The task of expanding seismic observation networks in the Russian Arctic is urgent.

The article gives a characteristic of the psephitic material obtained in the IODP-302 well on the Lomonosov Ridge. We provide data on the shape of rock fragments, their roundness, petrographic composition and distribution over lithological units of the well. It is shown that the major part of the psephites was delivered to the drilling point with ice, but several samples have a local origin and characterize the composition of the Mesozoic rocks. The roundness of the psephites consistently deteriorates in the younger enclosing sediments. The paper presents arguments that link this trend with the intensification of the ice regime. The consequence of the ice cover increase is the shortening of the time of psephites occurrence in the wave-surf zone, where large-sized material is rounding, by activating the “anchor” mechanism of the rock fragments capture. The level of change in petrographic associations of psephites generally coincides with the level of change in the association of heavy minerals, which is a consequence of the appearance of more distant sources areas. It is shown that the “paleo–trans–polar” ice drift system began to function in the middle Miocene. The paper draws conclusions about the evolution of the ice regime in the Arctic Ocean during the Cenozoic.

This work investigates a previously unknown phenomenon taking place when a large carrier ship moves in a channel made by an icebreaker narrower than the carrier ship. Usually, the studies of these movement conditions assumed the center line of the ship to coincide with the channel axis and the interaction of ship sides with channel edges to be symmetric. However, the observations made in Ice Basin and in real conditions have shown that in most of cases interaction of ship sides with channel edges is not symmetric. The ship moving in the channel breaks ice only with one of her sides, the other side only rubbing against the edge. The numerical assessments of ship position stability in the channel given in this paper made it possible to understand how this interaction becomes asymmetric. The study also yielded ice resistance assessments for a large carrier ship moving along the channel in these asymmetric conditions.

Estimation of the oil spill size at continuous spills on the moving sea surface or on the drifting ice field is the actual practical problem. Engineering estimation means the reduction of the hydrodynamic equations system to the balance of only two main forces that cause movement and resistance of the oil flow. From the simplified problem statement some practical relations were obtained for estimating the size of spill, including continuous oil spill with surface water currents presence, for spill onto porous snow-ice cover and onto the drifting ice cover. The obtained estimations can be used in more complicated models of oil spill transformation in the marine environment, primarily in the Arctic zone, and give basis for development of adequate responses on oil spills. The comparison of the obtained estimates with the self-similar solutions of the corresponding equations of motion of the spreading substance shows a satisfactory fit.