
Ivar Oskarovich Murdmaa- Dr. sci, Prof.
- Institute of Oceanology. PP Shirshov Russian Academy of Sciences
Ivar Oskarovich Murdmaa
- Dr. sci, Prof.
- Institute of Oceanology. PP Shirshov Russian Academy of Sciences
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156
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Introduction
Ivar Oskarovich Murdmaa currently works at the Laboratory of paleoceanology, P.P. Shirshov Institute of Oceanology. Ivar does research in Marine Geology, Lithology and Paleoceanography. Their current project is 'Lithology, stratigraphy and paleoceanography of the Atlantic and Pacific oceans'.
Current institution
Publications
Publications (156)
The content of sediment forming minerals in two cores from the eastern (ANS45-37) and western (ANS45-48) parts of the Vema transform fault valley is studied using the semi-quantitative XRD analysis of bulk powder sediment samples. The mineral composition of deep-sea sediments from the Amazone cone is also analyzed for comparison. It appeared that t...
Finding of vivianite is first described in a sediment core raised from the Cambridge Strait, western Franz Josef Land. The vivianite is represented by similar spherules mainly of 200–400 micrometers in diameter and by their rare aggregates. Distribution of the vivianite grains in the core is characterized by three maximal values (up to 2.7 grains p...
The paper provides the first lithology and age data from the Ameghino segment of the Atlantic Patagonian Margin. The multi-proxy study, including lithology, microfossils, magnetic susceptibility, color reflectance and accelerator mass spectrometry enables the litho- and chronostratigraphic frame of the six short (1 m) sediment cores from the contin...
The monograph "The Barents Sea System" is a continuation of a series of collective monographs devoted to systemic four-dimensional ("4-D oceanology") studies of the seas of the European part of Russia (White, Baltic, Black and Caspian), published in 2010–2018. All these monographs are linked by one idea and a single methodology. The new monograph p...
Lithological and micropaleontological (planktonic and benthic foraminifers, diatoms) studies in four sediment cores revealed major patterns of lithostratigraphy and biostratigraphy of contourites and gravitites in the uppermost sediment layer within the depth range 3500–4300 m of the northern sector of the Patagonian continental slope contourite sy...
The Ioffe Drift located in the Antarctic Bottom Water pathway from the Vema Channel to the Brazil Basin provides a suitable site to study past variations in bottom contour currents and their contribution to erosion and accumulation of deep-sea sediments. Our previous study of the reference core AI-2436 from the drift summit (Ivanova et al., 2016a)...
The Barents Sea offers a suitable location for documenting advection of warm and saline Atlantic Water (AW) into the Arctic and its impact on deglaciation and postglacial conditions. We investigate the timing, succession, and mechanisms of the transition from proximal glaciomarine to marine environment in the northwestern Barents Sea. Two studied s...
The submarine Shirshov Ridge is an independent system of terrigenous sedimentation, which is geomorphologically isolated from bottom terrigenous influx into the deep-water basin of the Bering Sea. Using the ridge as example, we studied background hemipelagic sedimentation of the finely dispersed terrigenous suspended matter from water column and de...
Here we present an almost complete and integrated Holocene record of marine and terrestrial palaeoenvironmental change from the NE shelf of the Black Sea. A dinoflagellate cyst record used to reconstruct Holocene sea-surface conditions highlights that the NE shelf was a brackish water environment, with a minimum salinity of 7 psu in the early-Holoc...
Цикл из двух статей посвящен изучению процессов эрозии дна и аккумуляции осадков в северном секторе ранее выделенной контуритовой системы континентального склона Патагонии, на 46-42°ю.ш., на глубинах от 2100 до 5200 м. В первой статье данного цикла приведена генетическая интерпретация оригинальных сейсмоакустических профилей высокого разрешения, по...
This brief communication describes the first finding of glauconite sand alternating with calcareous foraminiferal-coccolithic ooze on the Piedra Buena contourite terrace of the Patagonian continental slope at a depth of 2327 m. It is suggested that the fine-sand glauconite grains were supplied from the shelf during glaciations, rewashed and sorted...
Our new and previously published data on sea surface bioproductivity changes from different parts of the Pacific Ocean in the Northern Hemisphere were analyzed in relation to meridional overturning circulation during the last deglaciation. Synchronous episodes of upwelling intensification in the Eastern Equatorial Pacific and Southern Ocean cores i...
Geological research during cruise 43 of the R/V Akademik Ioffe was organized by the Geological Institute and the Shirshov Institute of Oceanology of the Russian Academy of Sciences (RAS). The cruise was combined with a vessel transit after the Arctic tourist season from October 2 through 31, 2013 (port of departure: Rotterdam, the Netherlands; port...
This study is focused on interpretation of ultrahigh-resolution seismoacoustic data from the northeastern slope of the Ceará Rise (Central Atlantic) acquired using the SES 2000 deep parametric narrow-beam subbottom profiler during cruise 35 of RV Akademik Ioffe in 2011. The geologic nature of most of the detected reflectors is constrained by correl...
Геологические исследования в 43-м рейсе НИС “Академик Иоффе” были организованы Геологическим институтом и Институтом океанологии им. П.П. Ширшова РАН. Рейс был совмещен с перегоном судна после завершения арктического туристического сезона в период со 2 по 31 октября 2013 г. (порт выхода – Роттердам, Голландия, порт прибытия – Монтевидео, Уругвай).
The present paper addresses the issue of the existence of inferred hiatus on the Shirshov Ridge in the western Bering Sea, which is represented by a sand layer allegedly produced by intensification of the bottom current at the penultimate glacial/last interglacial boundary. Intensification of current velocity near the ocean floor likely provoked wa...
Facts confirming the hypothesis of contourite sediment infill of the Equatorial Mid-Ocean Canyon (EMOC) are presented. We examined two cores recovered in Cruises 37 and 43 of the R/V Akademik Ioffe (2012, 2013). The cores recovered upper Quaternary miopelagic clays on the EMOC floor (AI-3149) and the adjacent abyssal plain (AI-2620). The study of t...
This paper aims to develop a theoretical hydromechanical model designed to explain slow motion of thin sediment suspension layer over the Black Sea abyssal plain. The suspension flows are regarded as a new lateral deep sea sediment transport mechanism differing from turbidity currents and other gravity flows in minor mass scale and velocity. The su...
Micropaleontological studies of the Black Sea, including ostracod records, have suggested that early Holocene salinity values were between ~5 and 10 practical salinity units (psu), contrasting with present values of 18–22 psu. However, more precise paleoenvironmental reconstructions based on ostracod assemblages require additional information relat...
According to the prevailing view, the Barents Sea shelf and surrounding archipelagoes were covered by a grounded ice sheet united with the Scandinavian ice sheet during the Last Glacial Maximum (LGM). Its decay started in the deep marginal troughs, the Bear Island Trough in the southwest, Kvitøya and Franz Victoria troughs in the north, ca. 19-18 c...
The expedition (chief E.V. Ivanova; chief scientist I.O. Murdmaa) included ten scientists who worked in geological (headed by S.M. Isachenko) and lithologi-cal (headed by D.G. Borisov) teams. Goals of expedition. The expedition was aimed at studying Quaternary sedimentation under influence of bottom currents in the South and Equatorial Atlantic in...
The geochemistry of Upper Quaternary organic-rich (Corg 3.7–10.0%) sediments recovered by the 40-m-long Core MD02-2508 from the upper continental slope of Baja California is compared to the chemical composition of sedimentary rocks from the Miocene Monterey Formation, California. It is ascertained that concentrations of most macroelements (Al, Ti,...
This paper presents reconstructions of ice sheet boundaries, lacustrine and marine paleobasins, as well as the connections of the Barents and Baltic seas with the North Atlantic from the Last Glacial Maximum to the Holocene. The reconstructions are based on original and published data obtained from the northern and western parts of the Barents Sea...
short description of the cruise results
The high-resolution SES-2000 deep seismic profiles performed by R/V Akademik Ioffe (2010) recorded a calcareous contourite drift over the Florianopolis fracture zone ridge, South Atlantic, named the Ioffe Drift. Core AI-2436 retrieved from the drift summit recovered calcareous nannofossil–foraminiferal ooze contourites with small amounts
of fine-gr...
The lithological analysis of sediments from Core SO201-2-85KL (18 m long) taken from the Shirshov Ridge in the western part of the Bering Sea (57°30.30′ N, 170°24.79′ E, water depth 968 m), which recovered the section spanning from the penultimate glaciation till Holocene, revealed their mostly terrigenous composition with several intercalations of...
The main goal of this work is to gain better understanding of interplay between gravity-driven
sedimentation processes and those related to bottom currents on the Brazil continental rise
during the Late Quaternary.
The study embraces an area close to the Sao Tome seamount (21°-23° S) that is located on the
continental rise in the SW Brazil Basin (S...
Thermomagnetic determination of the content and composition of native iron was accomplished in Miocene-Late Jurassic sediments and sedimentary rocks of the NW Atlantic recovered by DSDP holes 386, 387, 391A, and 391C. Native iron particles are ubiquitous therein. Presence of a zero group in the bar chart of native iron concentrations is a global fe...
The high-resolution seismic profiling during cruise 32 of the RV “Akademik Ioffe” (2010) discovered a large elongated contourite drift on the
ridge of the Rio Grande fracture zone (Brazil Basin, western South Atlantic). This sedimentary body with a thickness up to 300 m, named
Ioffe drift, is traced at water depth range from 3790 to 3980 m. Five se...
The se-�surface bioproductivity changes over the last 25 kyr were inferred from published data on
30 sediment cores from the open Northwest Pacific (NWP), Sea of Okhotsk, Bering Sea and Sea of Japan
accounting for the glacioeustatic se-�level changes. A novel method was developed to compare the variations of several independent productivity proxies...
A comprehensive multi-proxy study of mini-core Ash-2009-08 from the inner shelf of the northeastern Black Sea, allowed us to define recent environmental changes in the area, on a sub-decadal resolution. The age model of the core based on radionuclide (210Pb and 137Cs) measurements suggests an average sedimentation rate of 2 mm/y and, consequently,...
Very high resolution seismic profiles and a core were obtained during the cruises 33, 35, and 37 of the R/V Akademik Ioffe in the Columbia channel region (continental rise of Brazil, South Atlantic). The analysis of seismic facies and direct correlation of seismic and lithological data indicates that sedimentation in this area is generally controll...
Seismoacoustic investigations with a high-resolution parametric echo-sounder “SES 2000 deep” carried out on cruises 33, 35, and 37 of the R/V Akademik Ioffe revealed several erosional-depositional contourite systems on the São Paulo Plateau escarpment and its toe in the South Atlantic. Two contourite terraces related to interfaces between different...
In the period from September 23 until October 21, 2011, during the 35th cruise of the R/V Akademik Ioffe, combined with the vessel being run in the begin� ning of the 2011–2012 tourist season in the Antarctic, the regular studies in the framework of the seismofa� cies analysis of the Atlantic’s Quaternary deposits dur� ing transatlantic runs were p...
The thermomagnetic and microprobe analyses of sedimentary samples from DSDP 386, 387, 391A, and 391C boreholes in the northwestern Atlantic reveal the ubiquitous occurrence of particles of native iron. The concentrations of native iron are bimodal everywhere with the zero mode necessarily present. The nickel admixture in native iron forms two group...
Altogether, 16 specialists participated in the expe� dition: seven from the Institute of Oceanology of the Russian Academy of Sciences, three from the Institute of Geology of the Russian Academy of Sciences, three from the Institute of Atmosphere Physics of the Rus� sian Academy of Sciences, two from Pomeranian Uni� versity, and one from Innomar Te...
High-resolution seismic profiles collected by Parasound and SES-2000 deep profilers during Cruise 26 of the R/V Akademik Sergei Vavilov (2009) along the continental slope base of South America, NW Africa, and West Europe are correlated with the deep-sea drilling boreholes. Lithofacies interpretation of the Quaternary deep-water seismic facies of he...
Acoustically stratified seismic images are widely used in studies of
sedimentation mechanisms producing thick sedimentary aprons on
continental rises. However, insuffcient vertical resolution of seismic
records commonly restricts a more detailed interpretation of individual
reflectors within accumulations to reconstruct specifc short-term
sedimento...
Cited By (since 1996): 1, Export Date: 6 February 2013, Source: Scopus
Changes in paleoceanographic conditions on Shirshov Ridge, Western
Bering Sea, are inferred over the last two glacial cycles from the
high-resolution study of planktic and benthic foraminiferal assemblages
and IRD from the upper and lower parts of an 18m-long piston core
SO201-2-85KL (57°30.30'N, 170°24.79'E, water depth 968 m). Here
we present evi...
Core MD02-2508 retrieved from the plateau of the continental slope off Baja California recovered a 40-m-thick section of sapropel (up to 15% C-org), calcareous clay, and diatom ooze with the age of 120 ka at the core bottom. The section is subdivided into three units: Unit I (Holocene) consists of the laminated sapropel; Unit II comprising oxygen i...
Core MD02-2508 retrieved from the plateau of the continental slope off Baja California recovered a 40-m-thick section of sapropel (up to 15% Corg), calcareous clay, and diatom ooze with the age of 120 ka at the core bottom. The section is subdivided into three units: Unit I (Holocene) consists of the laminated sapropel; Unit II comprising oxygen is...
Contents of major elements in surface sediments of the White Sea were determined by the X-ray fluorescence method. Application
of the statistical analysis (principal component method and cluster analysis) made it possible to divide the sediments into
more or less homogeneous seven groups with different chemical and grain size compositions. In gener...
We analyzed n-alkanes spectra, TOC content, and C/N ratio in the upper 12 m of the giant IMAGES Core MD02-2529 from the Cocos Ridge (08°12.33'N; 84°07.32'W; 1619 m w.d.) to estimate terrestrial organic matter (TOM) and marine organic matter (MOM) contribution to the total organic matter budget in sediments. Multi-proxy studies of nannofossils, bent...
Contents of major elements in surface layer bottom sediments of the White Sea were determined by the X-ray fluorescence method. Application of the statistical analysis (principal component method and cluster analysis) made it possible to divide the sediments into more or less homogeneous seven groups with different chemical and grain size compositi...
Lithology, heavy mineral associations, and chemical composition of sediments studied in two gravity cores from Isfjord, Western
Spitsbergen, accompanied by high-frequency seismic records, provide a new insight on the provenance and glaciomarine sedimentation
in the fjord from the last deglaciation through the Holocene.
Lithology, heavy mineral associations, and chemical composition of bottom sediments studied in two gravity cores from Isfjord, Western Spitsbergen (Svalbard) accompanied by high-frequency seismic records, provide a new insight on provenance and glaciomarine sedimentation in the fjord from the last deglaciation through Holocene.
A multi-proxy study of four sediment cores from the Eastern (Caucasian) Black Sea shelf revealed five transgressive–regressive cycles overprinted on the general trend of glacioeustatic sea-level rise during the last 11,000 14C yr. These cycles are well represented in micro-andmacrofossil assemblages, sedimentation rates, and grain size variations....
Results of the experimental study of ion exchange properties of deep-sea pelagic sediments and related ferromanganese nodules
(FMN) are considered. The exchange complex of sediments and nodules includes Na+, K+, Ca2+, and Mg2+ cations. The FMNs also include Mn2+ cations. Series of reactivity of metal cations during exchange reactions in different t...
Results of an experimental study of ion exchange properties of Fe-Mn nodules and deep-sea pelagic host sediments are under consideration. The exchange complex of sediments and nodules includes Na+, K+, Ca2+, and Mg2+ cations. Fe-Mn nodules also include Mn2+ cations. Series of reactivity of metal cations during exchange reactions in different types...
Multiproxy sediment core records and high-frequency seismic profiles from Baltic, Norwegian, and Barents seas reveal a lithostratigraphic/seismostratigraphic sequence of glaciomarine (glaciolacustrine) deposits of the last deglaciation. The complete Late Weichselian glaciation to Recent sedimentary sequence recovered by core ASV-880 from the Franz-...
The mineral and chemical compositions of authigenic carbonates are studied by several methods in a sediment core obtained
from the axial zone of the Deryugin riftogenic basin. Manganese carbonates (kutnahorite, rhodochrosite) associated with manganiferous
calcite, manganiferous pyrite, and nontronite are first identified in the Sea of Okhotsk. Mang...
Twenty-two sediment cores raised from the central and eastern parts of the Barents Sea have been studied to reconstruct the evolution of the facies system since the Late Weichselian glaciation. Multiproxy records reveal four lithostratigraphic units, which reflect major development stages of paleoenvironments. Age control is provided by 23 AMS 14C...
New results of geomorphological, seismoacoustic, and lithological investigations on the upper continental slope off the Arkhipo-Osipovka
Settlement are presented. Here, a large submarine slump was discovered by seismic survey in 1998. The assumed slump body,
up to 200 m thick, rises 50–60 m above the valley floor that cuts the slope. Recent semiliq...
Mineral and chemical compositions of authigenic carbonates are studied by several methods in a sediment core collected in the axial zone of the Deryugin riftogenic basin. Manganese carbonates (kutnahorite, rhodochrosite) associated with manganiferous calcite, manganiferous pyrite, and nontronite are firstly identified in the Sea of Okhotsk. Mangane...
New results of geomorphological, seismoacoustic, and lithological investigations on the upper continental slope off the Arkhipo-Osipovka Settlement are presented. Here, a large submarine slump was discovered by seismic survey in 1998. The assumed slump body, up to 200 m thick, rises 50-60 m above the valley floor that cuts the slope. Recent semiliq...