sh.sePublications
Change search
ExportLink to record
Permanent link

Direct link
BETA

Project

Project type/Form of grant
Project grant
Title [sv]
IODP Expedition 347 Östersjöns miljöhistoria
Title [en]
IODP Expedition 347 Baltic Sea Paleoenvironment
Abstract [sv]
Expedition 347, scheduled as a Mission Specific Platform (MSP) for late Spring 2013, will focus on four main scientific objectives:(i) Climate and sea level dynamics of MIS 5 (ii) The complexities of the last glacial, MIS 4?MIS 2,(iii) glacial and Holocene (MIS 2?MIS 1) climate forcing, and (iv) Deep biosphere in the Baltic Sea Basin (BSB) sediments. The location of the BSB in the heartland of the Scandinavian Ice Sheet results in a complex development: repeated glaciations, responses to sea level and gateway threshold changes, large shifts in sedimentation patterns and high sedimentation rates. Its position also makes it a unique link between Eurasian and NW European terrestrial records. The sediments of this largest European intra-continental basin form a rare archive of climate evolution over the last glacial cycle. Furthermore, the large environmental variability the BSB has undergone during the last glacial cycle makes it optimal for new research on the deep biosphere. These objectives will be accomplished by drilling in six sub-basins, with targets including Anholt Loch and Little Belt, Eemian deposits from MIS 5; Bornholm Basin and Hanö Bay, complete records from MIS 4?2; Landsort Deep with a continuous record of the last ca 14000 years and Ångermanälven River, unique varved sediment record of the last >10000 years. The scientific communities around the Baltic Sea have by tradition had the BSB and its many intriguing scientific problems as a focal point for research.
Publications (10 of 11) Show all publications
Stepanova, A., Obrochta, S., Quintana Krupinski, N. B., Hyttinen, O., Kotilainen, A. & Andrén, T. (2019). Late Weichselian to Holocene history of the Baltic Sea as reflected in ostracod assemblages. Boreas, 48(3), 761-778
Open this publication in new window or tab >>Late Weichselian to Holocene history of the Baltic Sea as reflected in ostracod assemblages
Show others...
2019 (English)In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 48, no 3, p. 761-778Article in journal (Refereed) Published
Abstract [en]

The study presents the first description and analysis of ostracod records from three sites cored in different parts of the Baltic Sea during the IODP Expedition 347, Baltic Sea Paleoenvironment. Our data present the first high-resolution ostracod records from the Late Weichselian and Holocene sediments collected across the Baltic Sea Basin. Using published data on modern ostracod species ecology of the Baltic Sea, we were able to provide ostracod-based palaeoreconstructions of the history of the region. The stratigraphical framework for the sites is based on radiocarbon-based age models. The three studied sites reveal different ostracod assemblage successions that reflect environmental changes in the study area. Site M0060, located in the Kattegat area, contains the oldest ostracod assemblages that document a marine environment with very high sedimentation rates during the most recent deglaciation. Between ~13 000 and 7500 cal. a BP a modern-like near-shore environment developed. Site M0059 in the southwestern Baltic Sea, Little Belt area, contains assemblages reflecting the transition from a freshwater lake to the brackish Littorina Sea between ~7500 and 7300 cal. a BP. Site M0063 is the deepest location in the central Baltic, Landsort Deep, and yielded very limited ostracod data, but comparison with our organic carbon data allowed us to distinguish the Yoldia Sea, Ancylus Lake and Littorina Sea intervals. The ostracod record correlates well with the organic carbon record with alternation between periods of hypoxia and periods of low oxygen that still supported ostracods.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
National Category
Geology
Research subject
Baltic and East European studies
Identifiers
urn:nbn:se:sh:diva-37621 (URN)10.1111/bor.12375 (DOI)2-s2.0-85060756108 (Scopus ID)2207/3.1.1/2014 (Local ID)2207/3.1.1/2014 (Archive number)2207/3.1.1/2014 (OAI)
Funder
The Foundation for Baltic and East European Studies, 2207/3.1.1/2014
Available from: 2019-02-08 Created: 2019-02-08 Last updated: 2019-08-19Bibliographically approved
Mhatre, S. S., Kaufmann, S., Marshall, I. P., Obrochta, S., Andrén, T., Jørgensen, B. B. & Lomstein, B. A. (2019). Microbial biomass turnover times and clues to cellular protein repair in energy-limited deep Baltic Sea sediments. FEMS Microbiology Ecology, 95(6), Article ID fiz068.
Open this publication in new window or tab >>Microbial biomass turnover times and clues to cellular protein repair in energy-limited deep Baltic Sea sediments
Show others...
2019 (English)In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 95, no 6, article id fiz068Article in journal (Refereed) Published
Abstract [en]

The discovery of active microbial life deeply buried beneath the seafloor has opened important questions: how do microorganisms cope with extreme energy limitation, what is their metabolic activity, and how do they repair damages to essential biomolecules? We used a D:L-amino acid model to calculate microbial biomass turnover times. We used a metagenome and metatranscriptome analysis to investigate the distribution of the gene that encodes Protein-L-iso aspartate(D-aspartate) O-methyltransferase (PCMT), an enzyme which recognizes damaged L-isoapartyl and D-aspartyl residues in proteins and catalyzes their repair. Sediment was retrieved during the Integrated Ocean Drilling Program (IODP) Expedition 347 from Landsort Deep and the Little Belt in the Baltic Sea. The study covers the period from the Baltic Ice Lake ca. 13 000 years ago to the present. Our results provide new knowledge on microbial biomass turnover times and protein repair in relation to different regimes of organic matter input. For the first time, we show that the PCMT gene was widely distributed and expressed among phylogenetically diverse groups of microorganisms. Our findings suggest that microbial communities are capable of repairing D-amino acids within proteins using energy obtained from the degradation of a mixture of labile compounds in microbial necromass and more recalcitrant organic matter.

Place, publisher, year, edition, pages
Oxford University Press, 2019
Keywords
D:L-amino acid model, Glacial-Holocene transition, Protein-L-isoaspartate(D-aspartate) O-methyltransferase, biomass turnover times, marine deep biosphere, microbial necromass, organic matter diagenesis, protein repair
National Category
Environmental Sciences
Research subject
Baltic and East European studies
Identifiers
urn:nbn:se:sh:diva-38303 (URN)10.1093/femsec/fiz068 (DOI)000474762800012 ()31095297 (PubMedID)
Funder
EU, FP7, Seventh Framework Programme, 294200
Available from: 2019-06-11 Created: 2019-06-11 Last updated: 2019-08-19Bibliographically approved
van Wirdum, F., Andrén, E., Wienholz, D., Kotthoff, U., Moros, M., Fanget, A.-S. -., . . . Andrén, T. (2019). Middle to late holocene variations in salinity and primary productivity in the central Baltic Sea: A multiproxy study from the landsort deep. Frontiers in Marine Science, 6, Article ID 51.
Open this publication in new window or tab >>Middle to late holocene variations in salinity and primary productivity in the central Baltic Sea: A multiproxy study from the landsort deep
Show others...
2019 (English)In: Frontiers in Marine Science, E-ISSN 2296-7745, Vol. 6, article id 51Article in journal (Refereed) Published
Abstract [en]

Anthropogenic forcing has led to an increased extent of hypoxic bottom areas in the Baltic Sea during recent decades. The Baltic Sea ecosystem is naturally prone to the development of hypoxic conditions due to its geographical, hydrographical, geological, and climate features. Besides the current spreading of hypoxia, the Baltic Sea has experienced two extensive periods of hypoxic conditions during the Holocene, caused by changing climate conditions during the Holocene Thermal Maximum (HTM; 8–4.8 cal ka BP) and the Medieval Climate Anomaly (MCA; 1–0.7 cal ka BP). We studied the variations in surface and bottom water salinity and primary productivity and their relative importance for the development and termination of hypoxia by using microfossil and geochemical data from a sediment core retrieved from the Landsort Deep during IODP Expedition 347 (Site M0063). Our findings demonstrate that increased salinity was of major importance for the development of hypoxic conditions during the HTM. In contrast, we could not clearly relate the termination of this hypoxic period to salinity changes. The reconstructed high primary productivity associated with the hypoxic period during the MCA is not accompanied by considerable increases in salinity. Our proxies for salinity show a decreasing trend before, during and after the MCA. Therefore, we suggest that this period of hypoxia is primarily driven by increasing temperatures due to the warmer climate. These results highlight the importance of natural climate driven changes in salinity and primary productivity for the development of hypoxia during a warming climate.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2019
Keywords
paleoceanography, hypoxia, geochemistry, diatoms, foraminifera, palynomorphs, IODP Expedition 347
National Category
Climate Research
Research subject
Baltic and East European studies; Environmental Studies
Identifiers
urn:nbn:se:sh:diva-37781 (URN)10.3389/fmars.2019.00051 (DOI)2-s2.0-85061721558 (Scopus ID)1562/3.1.1/2013 (Local ID)1562/3.1.1/2013 (Archive number)1562/3.1.1/2013 (OAI)
Funder
The Foundation for Baltic and East European Studies, 1562/3.1.1/2013The Foundation for Baltic and East European Studies, 2207/3.1.1/2014Swedish Research Council, 826- 2012-5114
Note

This research was supported by the Foundation for Baltic and East European Studies (Grants 1562/3.1.1/2013 and 2207/3.1.1/2014), the Swedish Research Council (Grant 826- 2012-5114), the Carlsberg Foundation (IVAR-347 project) and Geocenter Denmark (DAN-IODP-SEIS project), the Independent Research Fund Denmark (Grant 7014-00113B, G-Ice), and the German Research Foundation (DFG, projects Ko3944/6-1 and Ko3944/8–1).

Available from: 2019-03-01 Created: 2019-03-01 Last updated: 2019-06-25Bibliographically approved
Warnock, J., Bauersachs, T., Kotthoff, U., Brandt, H.-T. & Andrén, E. (2018). Holocene environmental history of the Ångermanälven Estuary, northern Baltic Sea. Boreas, 47(2), 593-608
Open this publication in new window or tab >>Holocene environmental history of the Ångermanälven Estuary, northern Baltic Sea
Show others...
2018 (English)In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 47, no 2, p. 593-608Article in journal (Refereed) Published
Abstract [en]

The Baltic Sea has experienced a complex geological history, with notable swings in salinity driven by changes to its connection with the Atlantic and glacio-isostatic rebound. Sediments obtained during International Ocean Drilling Program Expedition 347 allow the study of the effects of these changes on the ecology of the Baltic in high resolution through the Holocene in areas where continuous records had not always been available. Sites M0061 and M0062, drilled in the Ångermanälven Estuary (northern Baltic Sea), contain records of Holocene-aged sediments and microfossils. Here we present detailed records of palaeoecological and palaeoenvironmental changes to the Ångermanälven Estuary inferred from diatom, palynomorph and organic-geochemical data. Based on diatom assemblages, the record is divided into four zones that comprise the Ancylus Lake, Littorina Sea, Post-Littorina Sea and Recent Baltic Sea stages. The Ancylus Lake phase is initially characterized as oligotrophic, with the majority of primary productivity in the upper water column. This transition to a eutrophic state continues into the Initial Littorina Sea stage. The Initial Littorina Sea stage contains the most marine phase recorded here, as well as low surface water temperatures. These conditions end before the Littorina Sea stage, which is marked by a return to oligotrophic conditions and warmer waters of the Holocene Thermal Maximum. Glacio-isostatic rebound leads to a shallowing of the water column, allowing for increased benthic primary productivity and stratification of the water column. The Medieval Climate Anomaly is also identified within Post-Littorina Sea sediments. Modern Baltic sediments and evidence of human-induced eutrophication are seen. Human influence upon the Baltic Sea begins c. 1700 cal. a BP and becomes more intense c. 215 cal. a BP.

 

National Category
Earth and Related Environmental Sciences
Research subject
Environmental Studies; Baltic and East European studies
Identifiers
urn:nbn:se:sh:diva-33375 (URN)10.1111/bor.12281 (DOI)000428369500015 ()2-s2.0-85029216223 (Scopus ID)2207/3.1.1/2014 (Local ID)2207/3.1.1/2014 (Archive number)2207/3.1.1/2014 (OAI)
Funder
The Foundation for Baltic and East European StudiesGerman Research Foundation (DFG), KO 3944/6-1German Research Foundation (DFG), BA 3841/5-1
Note

Also funded by IODP PEA.

Available from: 2017-09-13 Created: 2017-09-13 Last updated: 2019-08-19Bibliographically approved
Hyttinen, O., Kotilainen, A. T., Virtasalo, J. J., Kekäläinen, P., Snowball, I., Obrochta, S. & Andrén, T. (2017). Holocene stratigraphy of the Ångermanälven River estuary, Bothnian Sea. Geo-Marine Letters, 37(3), 273-288
Open this publication in new window or tab >>Holocene stratigraphy of the Ångermanälven River estuary, Bothnian Sea
Show others...
2017 (English)In: Geo-Marine Letters, ISSN 0276-0460, E-ISSN 1432-1157, Vol. 37, no 3, p. 273-288Article in journal (Refereed) Published
Abstract [en]

This study explores the Holocene depositional succession at the IODP Expedition 347 sites M0061 and M0062 in the vicinity of the Ångermanälven River estuary in the Bothnian Sea sector of the Baltic Sea in northern Scandinavia. Site M0061 is located in a coastal offshore setting (87.9 m water depth), whereas site M0062 is fully estuarine (69.3 m water depth). The dataset comprises acoustic profiles and sediment cores collected in 2007 and late 2013 respectively. Three acoustic units (AUs) were recognized. Lowermost AU1 is interpreted as a poorly to discontinuous stratified glaciofluvial deposit, AU2 as a stratified conformable drape of glaciolacustrine origin, and AU3 as a poorly stratified to stratified mud drift. A strong truncating reflector separates AU2 and AU3. Three lithological units (LUs) were defined in the sediment cores. LU1 consists of glaciofluvial sand and silt gradating into LU2, which consists of glaciolacustrine varves. A sharp contact interpreted as a major unconformity separates LU2 from the overlying LU3 (brackish-water mud). In the basal part of LU3, one debrite (site M0061) or two debrites (site M0062) were recognized. Information yielded from sediment physical properties (magnetic susceptibility, natural gamma ray, dry bulk density), geochemistry (total carbon, total organic carbon, total inorganic carbon and nitrogen), and grain size support the LU division. The depositional succession was formally subdivided into two alloformations: the Utansjö Alloformation and overlying Hemsön Alloformation; the Utansjö Alloformation was further subdivided into two lithostratigraphic formations: the Storfjärden and Åbordsön formations. The Storfjärden (sandy outwash) and Åbordsön (glaciolacustrine rhythmite) formations represent a glacial retreat systems tract, which started at ca. 10.6 kyr BP. Their deposition was mainly controlled by meltwater from the retreating ice margin, glacio-isostatic land uplift and the regressive (glacial) lake level. The Hemsön Alloformation (organic-rich brackish-water mud) represents a period of forced regression, starting possibly at ca. 9.5 kyr BP. At about 7 kyr BP, brackish water reached the study area as a result of the mid-Holocene marine flooding of the Baltic Sea Basin, but the rapid land uplift soon surpassed the associated (Littorina) transgression. Changed near-bottom current patterns, caused by the establishment of a permanent halocline, and the reduced sediment consistency caused by increased organic deposition resulted in a sharp and erosional base of the brackish-water mud. Estuarine processes and salinity stratification at site M0062 started to play a more important role. This study applies a combined allostratigraphic and lithostratigraphic approach over the conventional Baltic Sea stages. This approach makes it more straightforward to study this Baltic Sea deglaciation–postglacial sequence and compare it to other formerly glaciated shallow sea estuaries.

National Category
Earth and Related Environmental Sciences
Research subject
Environmental Studies; Politics, Economy and the Organization of Society
Identifiers
urn:nbn:se:sh:diva-31525 (URN)10.1007/s00367-016-0490-2 (DOI)000401411000006 ()2-s2.0-85027842380 (Scopus ID)
Available from: 2016-12-23 Created: 2016-12-23 Last updated: 2019-06-25Bibliographically approved
Kotthoff, U., Groeneveld, J., Ash, J., Fanget, A.-S., Krupinski, N., Peyron, O., . . . Bauersachs, T. (2017). Reconstructing Holocene temperature and salinity variations in the western Baltic Sea region: a multi-proxy comparison from the Little Belt (IODP Expedition 347, Site M0059). Biogeosciences, 14, 5607-5632
Open this publication in new window or tab >>Reconstructing Holocene temperature and salinity variations in the western Baltic Sea region: a multi-proxy comparison from the Little Belt (IODP Expedition 347, Site M0059)
Show others...
2017 (English)In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 14, p. 5607-5632Article in journal (Refereed) Published
Abstract [en]

Sediment records recovered from the Baltic Sea during Integrated Ocean Drilling Program Expedition 347 provide a unique opportunity to study paleoenvironmental and climate change in central and northern Europe. Such studies contribute to a better understanding of how environmental parameters change in continental shelf seas and enclosed basins. Here we present a multi-proxy-based reconstruction of paleotemperature (both marine and terrestrial), paleosalinity, and paleoecosystem changes from the Little Belt (Site M0059) over the past  ∼  8000 years and evaluate the applicability of inorganic- and organic-based proxies in this particular setting. All salinity proxies (diatoms, aquatic palynomorphs, ostracods, diol index) show that lacustrine conditions occurred in the Little Belt until  ∼  7400 cal yr BP. A connection to the Kattegat at this time can thus be excluded, but a direct connection to the Baltic Proper may have existed. The transition to the brackish–marine conditions of the Littorina Sea stage (more saline and warmer) occurred within  ∼  200 years when the connection to the Kattegat became established after  ∼  7400 cal yr BP. The different salinity proxies used here generally show similar trends in relative changes in salinity, but often do not allow quantitative estimates of salinity. The reconstruction of water temperatures is associated with particularly large uncertainties and variations in absolute values by up to 8 °C for bottom waters and up to 16 °C for surface waters. Concerning the reconstruction of temperature using foraminiferal Mg  /  Ca ratios, contamination by authigenic coatings in the deeper intervals may have led to an overestimation of temperatures. Differences in results based on the lipid paleothermometers (long chain diol index and TEXL86) can partly be explained by the application of modern-day proxy calibrations to intervals that experienced significant changes in depositional settings: in the case of our study, the change from freshwater to marine conditions. Our study shows that particular caution has to be taken when applying and interpreting proxies in coastal environments and marginal seas, where water mass conditions can experience more rapid and larger changes than in open ocean settings. Approaches using a multitude of independent proxies may thus allow a more robust paleoenvironmental assessment.

National Category
Geosciences, Multidisciplinary
Research subject
Environmental Studies
Identifiers
urn:nbn:se:sh:diva-33885 (URN)10.5194/bg-14-5607-2017 (DOI)000417849900001 ()2-s2.0-85038405810 (Scopus ID)2207/3.1.1/2014 (Local ID)2207/3.1.1/2014 (Archive number)2207/3.1.1/2014 (OAI)
Funder
The Foundation for Baltic and East European Studies, 1562/3.1.1/2013The Foundation for Baltic and East European Studies, 2207/3.1.1/2014
Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2019-08-19Bibliographically approved
Obrochta, S. P., Andrén, T., Fazekas, S. Z., Lougheed, B. C., Snowball, I., Yokoyama, Y., . . . Fehr, A. (2017). The undatables: Quantifying uncertainty in a highly expanded Late Glacial-Holocene sediment sequence recovered from the deepest Baltic Sea basin—IODP Site M0063. Geochemistry Geophysics Geosystems, 18(3), 858-871
Open this publication in new window or tab >>The undatables: Quantifying uncertainty in a highly expanded Late Glacial-Holocene sediment sequence recovered from the deepest Baltic Sea basin—IODP Site M0063
Show others...
2017 (English)In: Geochemistry Geophysics Geosystems, ISSN 1525-2027, E-ISSN 1525-2027, Vol. 18, no 3, p. 858-871Article in journal (Refereed) Published
Abstract [en]

Laminated, organic-rich silts and clays with high dissolved gas content characterize sediments at IODP Site M0063 in the Landsort Deep, which at 459 m is the deepest basin in the Baltic Sea. Cores recovered from Hole M0063A experienced significant expansion as gas was released during the recovery process, resulting in high sediment loss. Therefore, during operations at subsequent holes, penetration was reduced to 2 m per 3.3 m core, permitting expansion into 1.3 m of initially empty liner. Fully filled liners were recovered from Holes B through E, indicating that the length of recovered intervals exceeded the penetrated distance by a factor of >1.5. A typical down-core logarithmic trend in gamma density profiles, with anomalously low-density values within the upper ∼1 m of each core, suggests that expansion primarily occurred in this upper interval. Thus, we suggest that a simple linear correction is inappropriate. This interpretation is supported by anisotropy of magnetic susceptibility data that indicate vertical stretching in the upper ∼1.5 m of expanded cores. Based on the mean gamma density profiles of cores from Holes M0063C and D, we obtain an expansion function that is used to adjust the depth of each core to conform to its known penetration. The variance in these profiles allows for quantification of uncertainty in the adjusted depth scale. Using a number of bulk 14C dates, we explore how the presence of multiple carbon source pathways leads to poorly constrained radiocarbon reservoir age variability that significantly affects age and sedimentation rate calculations.

Keywords
Paleoclimatology and paleoceanography, Uncertainty quantification, Sedimentation, Statistical methods: Inferential, Magnetic and electrical methods, sediment expansion, radiocarbon, paleomagnetics, age modeling
National Category
Environmental Sciences
Research subject
Baltic and East European studies
Identifiers
urn:nbn:se:sh:diva-32368 (URN)10.1002/2016GC006697 (DOI)000399677600003 ()2-s2.0-85015164849 (Scopus ID)2207/3.1.1/2014 (Local ID)2207/3.1.1/2014 (Archive number)2207/3.1.1/2014 (OAI)
Funder
The Foundation for Baltic and East European Studies, 2207/3.1.1/2014Swedish Research Council, 2012-5114
Available from: 2017-04-10 Created: 2017-04-10 Last updated: 2019-06-25Bibliographically approved
Andrén, T., Jørgensen, B. B., Cotterill, C., Green, S. & Andrén, E. (2015). Baltic Sea Basin Paleoenvironment: Expedition 347 of the mission-specific drilling platform  from and to Kiel, Germany Sites M0059–M0067  12 September–1 November 2013. Integrated Ocean Drilling Program
Open this publication in new window or tab >>Baltic Sea Basin Paleoenvironment: Expedition 347 of the mission-specific drilling platform  from and to Kiel, Germany Sites M0059–M0067  12 September–1 November 2013
Show others...
2015 (English)Report (Other academic)
Place, publisher, year, edition, pages
Integrated Ocean Drilling Program, 2015
Series
Proceedings of the Integrated Ocean Drilling Programme, ISSN 1930-1014 ; 347
National Category
Environmental Sciences
Identifiers
urn:nbn:se:sh:diva-28067 (URN)10.2204/iodp.proc.347.2015 (DOI)
Available from: 2015-08-14 Created: 2015-08-14 Last updated: 2019-06-25Bibliographically approved
Andrén, T., Jørgensen, B. B., Cotterill, C. & Green, S. (2015). IODP expedition 347: Baltic Sea basin paleoenvironment and biosphere. Scientific Drilling, 20, 1-12
Open this publication in new window or tab >>IODP expedition 347: Baltic Sea basin paleoenvironment and biosphere
Show others...
2015 (English)In: Scientific Drilling, ISSN 1816-8957, E-ISSN 1816-3459, Vol. 20, p. 1-12Article in journal (Refereed) Published
Abstract [en]

The Integrated Ocean Drilling Program (IODP) expedition 347 cored sediments from different settings of the Baltic Sea covering the last glacial–interglacial cycle. The main aim was to study the geological development of the Baltic Sea in relation to the extreme climate variability of the region with changing ice cover and major shifts in temperature, salinity, and biological communities. Using the Greatship Manisha as a European Consortium for Ocean Research Drilling (ECORD) mission-specific platform, we recovered 1.6 km of core from nine sites of which four were additionally cored for microbiology. The sites covered the gateway to the North Sea and Atlantic Ocean, several sub-basins in the southern Baltic Sea, a deep basin in the central Baltic Sea, and a river estuary in the north.

 

The waxing and waning of the Scandinavian ice sheet has profoundly affected the Baltic Sea sediments. During theWeichselian, progressing glaciers reshaped the submarine landscape and displaced sedimentary deposits from earlier Quaternary time. As the glaciers retreated they left a complex pattern of till, sand, and lacustrine clay, which in the basins has since been covered by a thick deposit of Holocene, organic-rich clay. Due to the stratified water column of the brackish Baltic Sea and the recurrent and widespread anoxia, the deeper basins harbor laminated sediments that provide a unique opportunity for high-resolution chronological studies.

 

The Baltic Sea is a eutrophic intra-continental sea that is strongly impacted by terrestrial runoff and nutrient fluxes. The Holocene deposits are recorded today to be up to 50m deep and geochemically affected by diagenetic alterations driven by organic matter degradation. Many of the cored sequences were highly supersaturated with respect to methane, which caused strong degassing upon core recovery. The depth distributions of conservative sea water ions still reflected the transition at the end of the last glaciation from fresh-water clays to Holocene brackish mud. High-resolution sampling and analyses of interstitial water chemistry revealed the intensive mineralization and zonation of the predominant biogeochemical processes. Quantification of microbial cells in the sediments yielded some of the highest cell densities yet recorded by scientific drilling.

Keywords
Baltic Sea, paleoenvironment, IODP, ECORD
National Category
Geology
Research subject
Environmental Studies; Baltic and East European studies
Identifiers
urn:nbn:se:sh:diva-28908 (URN)10.5194/sd-20-1-2015 (DOI)000379423200002 ()2-s2.0-84952026569 (Scopus ID)48/42/2013 (Local ID)48/42/2013 (Archive number)48/42/2013 (OAI)
Funder
Swedish Research Council
Available from: 2015-12-17 Created: 2015-12-17 Last updated: 2019-06-25Bibliographically approved
Andrén, T., Andrén, E. & Zhang, R. (2014). Baltic Sea Basin Paleoenvironment: paleoenvironmental evolution of the Baltic Sea Basin through the last glacial cycle. Integrated Ocean Drilling Program
Open this publication in new window or tab >>Baltic Sea Basin Paleoenvironment: paleoenvironmental evolution of the Baltic Sea Basin through the last glacial cycle
2014 (English)Report (Other academic)
Place, publisher, year, edition, pages
Integrated Ocean Drilling Program, 2014. p. 102
Series
IODP Preliminary report ; 347
National Category
Environmental Sciences
Identifiers
urn:nbn:se:sh:diva-24999 (URN)10.2204/iodp.pr.347.2014 (DOI)
Available from: 2014-10-23 Created: 2014-10-10 Last updated: 2019-06-25Bibliographically approved
Principal InvestigatorAndrén, Thomas
Coordinating organisation
Södertörn University
Funder
Period
2013-01-01 - 2013-12-31
Keywords [sv]
Östersjö- och Östeuropaforskning
Keywords [en]
Baltic and East European studies
National Category
Climate ResearchGeologyOceanography, Hydrology, Water Resources
Identifiers
DiVA, id: project:1873Project, id: 2012-05114_VR