G.I. Ivanov, V.P. Shevchenko, A.P. Kalenich, A.G. IvanovУДК 550
M ixed zone of fresh and salinity marine water attracted geologist for a long time. Last time concerning with large scale geoecological investigation on the shelf these problems have been obtained new sounding as important physical-chemical barrier for imputing pollutants marine ecosystems. For Western Russian Arctic Shelf which has got huge supply province as archipelago Novaya Zemlya with its big river, this problem is coming one the most important.
In theoretic aspects ecogeochemical barrier zone was developed mostly by A.P. Lisitzin (Lisitzin, 1994, 1999) as system marginal filter (SMF). SMF arise from to the mixed fresh and salinity water, in mouth rivers. Its size is from hundreds meters to hundreds kilometers for big rivers and estimated by physic-geographical environments or climatic zonality. Investigation done on offshore Novaya Zemlya shelf in 1992-2005 show whole row original of SMF features here (Ivanov et al., 2004, 2005). More detailed study was carryout in Bezymyannya Bay (Fig. 1).
The most important feature of Novaya Zemlya offshore is occurrence of flood and ebb currents with changes sea levels in intervals from 70 to 100 cm. Besides, intensive neotectonic movements promoted generation of number of bays and shallow water lagoons which most far bitted in the land.
Detailed hydrochemical study and land observation shows, that structure of SMF has not only frontally but and horizontal boundaries as well. Speed of physical-chemical activity on these boundaries characterized different directions and value. During the flood, “heavy” density salinity water move to mouth of river to support outlet fresh water of Bezymyannaya River. Fresh water, is more lighter and less density spreading under marine water formatted on the all bay area lateral zone of mixed waters.
In addition Its important to emphasis that direction and speed movement of manifold water are different for value.
During of ebb we are monitoring different scene. Fresh and salinity water move in this same direction, but with different speed, which estimated their physical-chemical properties.
In this same time, in the mouth river format longitudinal vertical moving zone of mixed water, where meet marine salinity water outflow from lagoon from one side and fresh water of river and back moving salinity water from bay, from the other side.
Important factor which formatting structure of SMF is geomorphological description of bay - top of spillway, small trough and canyon.
Considering dynamics of processes, conditioned by changes intensively and their directions, accumulation of sediments not occur. All materials carry off outside boundary marginal filter, its where transport further by power (up 110 см/s) along shore currents .
Contrast of zonality estimate by season of year, hydrometeorological condition, power and direction of storms. Detail organo-geochemical investigation show that organic carbon has terrigenous sources, deep degree of conversion and low concentration (in average 1%).