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20 Research products, page 1 of 2

  • European Marine Science
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  • European Commission
  • EC|FP7
  • PETA-CARB

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  • Open Access English
    Authors: 
    Nitze, Ingmar; Fuchs, Matthias; Strauss, Jens; Günther, Frank; Wetterich, Sebastian; Kizyakov, Alexander; Fritz, Michael; Opel, Thomas; Grigoriev, Mikhail N; Maksimov, Georgii T; +2 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | Nunataryuk (773421), EC | PETA-CARB (338335)

    Permafrost thaw and ice wedge degradation lead to drastic landscape changes in the permafrost region. With this data set we investigated the cliff retreat of the Sobo-Sise Cliff (SSC), a high ice-bearing yedoma cliff in the Lena River Delta. The 1,660 m long cliff SSC extends from 72°32'34 N / 128°15'59 E to 72°32'06 N / 128°18'21 E and is located on the Sardakhskaya channel, which is one of the main Lena river branches in the Lena River Delta. Erosion rates for the SSC were determined based on satellite images from different sensors (Corona, Hexagon, Landsat, Planet cube-sat) for the period 1965-2018. Cliff front lines were manually digitized and erosion rates were calculated with the Digital Shoreline Analysis System (DSAS) tool (Himmelstoos et al. 2018). The study Fuchs et al. (2020) (doi:10.3389/feart.2020.00336) shows that the up to 27.7 m high SSC erodes in average 15.7 m yr-1 (2015-2018). During the entire observed time period from 1965-2018, the SSC retreated in average 484 m (ranging from 322 - 680 m). This data set compilation consist of three GIS shapefiles with a corresponding metadata file and a table of the mean annual erosion rates of the yedoma SSC for the time periods 1965-1975, 1975-2000, 2000-2005, 2005-2010, 2010-2015, and 2015-2018, as well as the absolute cliff retreat rates over the entire period 1965-2018, which are derived from remote sensing imagery analyzed with the DSAS tool. In addition, the cliff front lines for each investigated time step are provided as well as the separation between yedoma and alas deposits for each time step. Related trend data for this region, based on Landsat trend analysis are available at: doi:10.1594/PANGAEA.884136 (Nitze, 2018).

  • Open Access English
    Authors: 
    Jongejans, Loeka Laura; Mangelsdorf, Kai; Strauss, Jens;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    These datasets describe a 31.5 m long sediment core taken from beneath thermokarst lake Goltsovoye Lake (71.74515 N, 129.30217 E) on the Bykovsky Peninsula, northeastern Siberia. The thermokarst lake was 510 cm deep. Here, we report the depths from the ice surface as well as from the sediment surface. The first dataset presents biogeochemical and hydrochemical parameters of sediment core PG2412. Biogeochemical analyses include total nitrogen (TN) content, total carbon (TC) content, total organic carbon (TOC) content and stable carbon isotopes (δ13C). δ13C was measured for samples with TOC > 0.1 wt %. Hydrochemical parameters include pore water content, pH and electrical conductivity (EC). The second dataset presents the grain size distribution of sediment core PG2412. The fraction > 1 mm is not included. The third dataset presents the radiocarbon ages from samples from sediment core PG2412. Calibrated and rounded calibrated ages are presented. Calibrations were performed according to Stuiver et al. (2017) using CALIB 7.1 software and the IntCal13 calibration curve. The fourth dataset presents the n-alkane data from samples from sediment core PG2412. Concentrations of n-alkanes in the range n-C23 to n-C33 are given in µg/g sediment and µg/g TOC. From the n-alkane concentrations, we calculated the following indices: average chain length (ACL), carbon preference index (CPI), odd-over-even predominance (OEP), n-Alkane ratio, aquatic plant proxy (Paq) and terrestrial plant proxy (Pwax).

  • Open Access English
    Authors: 
    Angelopoulos, Michael; Overduin, Pier Paul; Jenrich, Maren; Nitze, Ingmar; Günther, Frank; Strauss, Jens; Westermann, Sebastian; Schirrmeister, Lutz; Kholodov, Alexander L; Krautblatter, Michael; +2 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | Nunataryuk (773421), EC | PETA-CARB (338335)

    In July 2017, we collected apparent resistivity data (ohm-m) in a sub-aquatic permafrost environment on the southern coastline of the Bykovsky Peninsula in northeast Siberia. The project goal was to determine the depth to the top of frozen sediment for multiple submerged landscapes. The submerged landscapes included ice-rich Yedoma permafrost, permafrost that had undergone prior thermokarst (Alases), and a former lagoon (i.e. offshore at the lagoon's coastline positions in earlier years). The data was collected with an IRIS Syscal Pro Deep Marine resistivity system that was equipped with a GPS and an echo-sounder to record water depths. The geoelectric cable had an electrode separation of 10 m and the electrodes were arranged in a reciprocal Wenner Schlumberger array. The offset between the first electrode and the boat was approximately 10 m.

  • English
    Authors: 
    Biskaborn, Boris K; Sens, Miriam;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    The dataset describes a 5 m long sediment core taken from beneath thermokarst lake Goltsovoye Lake on the Bykovsky Peninsula, northeastern Siberia. Core location: N 71.74530 E 129.30243. The data represent biogeochemical parameters of sediment core PG2420. Biogeochemical analyses include total organic carbon (TOC) content and stable carbon isotopes (δ13C). δ13C was measured for samples with TOC > 0.1 wt %. The data also include radiocarbon measurements. Calibrated and rounded calibrated ages are presented. Calibrations were performed according to Stuiver et al. (2017) using CALIB 7.1 software and the IntCal13 calibration curve. To all data, the vertical position in the sediment core is given in cm (midth of sample) measured from the ice surface on top of the lake. Depth from ice surface to sediment surface was 510 cm.

  • Open Access English
    Authors: 
    Treat, Claire C; Broothaerts, Nils; Dalton, April S; Dommain, René; Douglas, Tom; Drexler, Judith; Finkelstein, Sarah A; Grosse, Guido; Hope, Geoffrey; Hutchings, Jack A; +20 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: NSF | Collaborative Research: P... (1502891), NSERC , NSF | Collaborative Research: R... (1246190), NSF | Collaborative Research: S... (1107981), NSF | Collaborative Research: P... (1304823), EC | PETA-CARB (338335)

    We present the first synthesis of global peatland extent through the last glacial cycle (130 ka) based on >975 detailed stratigraphic descriptions from exposures, soil pits, and sediment cores. Buried peats are defined as organic-rich sediments overlain by mineral sediments. Also included are deposits rich in wetland macrofossils indicated a local peatland environment. The dataset includes location (lat/long), chronologic information (when available), a description of the buried peat sediment, overlying and underlying sediments, whether geochemical information is available, and the original references.

  • Open Access English
    Authors: 
    Fuchs, Matthias; Grosse, Guido; Strauss, Jens; Günther, Frank; Grigoriev, Mikhail N; Maximov, Georgy M; Hugelius, Gustaf;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    Ice rich Yedoma-dominated landscapes store considerable amounts of organic carbon (C) and nitrogen (N) and are vulnerable to degradation under climate warming. We investigate the C and N pools in two thermokarst-affected Yedoma landscapes - on Sobo-Sise Island and on Bykovsky Peninsula in the North of East Siberia. Soil cores up to three meters depth were collected along geomorphic gradients and analysed for organic C and N contents. A high vertical sampling density in the profiles allowed the calculation of C and N stocks for short soil column intervals and enhanced understanding of within-core parameter variability. Profile-level C and N stocks were scaled to the landscape level based on landform classifications from five-meter resolution, multispectral RapidEye satellite imagery. Mean landscape C and N storage in the first meter of soil for Sobo-Sise Island is estimated to be 20.2 kg C/m**-2 and 1.8 kg N/m**-2 and for Bykovsky Peninsula 25.9 kg C/m**-2 and 2.2 kg N/m**-2. Radiocarbon dating demonstrates the Holocene age of thermokarst basin deposits but also suggests the presence of thick Holocene aged cover layers which can reach up to two meters on top of intact Yedoma landforms. Reconstructed sedimentation rates of 0.10 mm/yr - 0.57 mm/yr suggest sustained mineral soil accumulation across all investigated landforms. Both Yedoma and thermokarst landforms are characterized by limited accumulation of organic soil layers (peat). We further estimate that an active layer deepening by about 100 cm will increase organic C availability in a seasonally thawed state in the two study areas by ~5.8 Tg (13.2 kg C/m**-2). Our study demonstrates the importance of increasing the number of C and N storage inventories in ice-rich Yedoma and thermokarst environments in order to account for high variability of permafrost and thermokarst environments in pan-permafrost soil C and N pool estimates.

  • Open Access English
    Authors: 
    Lenz, Josefine; Wetterich, Sebastian; Jones, Benjamin M; Meyer, Hanno; Bobrov, Anatoly A; Grosse, Guido;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    Permafrost degradation influences the morphology, biogeochemical cycling and hydrology of Arctic landscapes over a range of time scales. To reconstruct temporal patterns of early to late Holocene permafrost and thermokarst dynamics, site-specific palaeo-records are needed. Here we present a multi-proxy study of a 350-cm-long permafrost core from a drained lake basin on the northern Seward Peninsula, Alaska, revealing Lateglacial to Holocene thermokarst lake dynamics in a central location of Beringia. Use of radiocarbon dating, micropalaeontology (ostracods and testaceans), sedimentology (grain-size analyses, magnetic susceptibility, tephra analyses), geochemistry (total nitrogen and carbon, total organic carbon, d13Corg) and stable water isotopes (d18O, dD, d excess) of ground ice allowed the reconstruction of several distinct thermokarst lake phases. These include a pre-lacustrine environment at the base of the core characterized by the Devil Mountain Maar tephra (22 800±280 cal. a BP, Unit A), which has vertically subsided in places due to subsequent development of a deep thermokarst lake that initiated around 11 800 cal. a BP (Unit B). At about 9000 cal. a BP this lake transitioned from a stable depositional environment to a very dynamic lake system (Unit C) characterized by fluctuating lake levels, potentially intermediate wetland development, and expansion and erosion of shore deposits. Complete drainage of this lake occurred at 1060 cal. a BP, including post-drainage sediment freezing from the top down to 154 cm and gradual accumulation of terrestrial peat (Unit D), as well as uniform upward talik refreezing. This core-based reconstruction of multiple thermokarst lake generations since 11 800 cal. a BP improves our understanding of the temporal scales of thermokarst lake development from initiation to drainage, demonstrates complex landscape evolution in the ice-rich permafrost regions of Central Beringia during the Lateglacial and Holocene, and enhances our understanding of biogeochemical cycles in thermokarst-affected regions of the Arctic.

  • Open Access English
    Authors: 
    Angelopoulos, Michael; Westermann, Sebastian; Overduin, Pier Paul; Faguet, Alexey; Olenchenko, Vladimir; Grosse, Guido; Grigoriev, Mikhail N;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    Two separate field excursions were carried out in 2017 to investigate subsea permafrost degradation offshore of the Bykovsky Peninsula in Siberia. In April, four ice cores were drilled offshore to measure sea ice thickness, snow thickness, and water depth. In July, multiple conductivity, temperature, and depths (CTD) sensors were deployed to measure seawater properties like temperature, salinity, and electrical conductivity. Furthermore, electrical resistivity surveys were taken perpendicular to and crossing the shoreline of the Bykovsky Peninsula to estimate the depth of ice-bearing permafrost.

  • Open Access English
    Authors: 
    Fuchs, Matthias; Lenz, Josefine; Jock, Suzanne; Nitze, Ingmar; Jones, Benjamin M; Strauss, Jens; Günther, Frank; Grosse, Guido;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    This data set includes the data for the publication Fuchs et al. (2019), Organic carbon and nitrogen stocks along a thermokarst lake sequence in Arctic Alaska, doi:10.1029/2018JG004591. Impacts of successive thermokarst lake stages on soil organic carbon and nitrogen storage, Arctic Alaska. This study combines terrestrial and lacustrine cores to a depth of two meters for a carbon and nitrogen stock estimation in a heavily thermokarst affected study region as well as describes the landscape chronology of the study area which is characterized by multiple drained thermokarst lake basins of different generations. The first data set (doi:10.1594/PANGAEA.895163) includes the raw laboratory data (TOC, TC, TN, C/N) from the permafrost cores collected at the Teshekpuk Lake Area. The data for the lacustrine cores are published on Pangaea and accessible with the link: https://doi.org/10.1594/PANGAEA.864814 (Lenz et al., 2016). All laboratory analyses on the terrestrial cores were carried out at the Alfred Wegener Institute Potsdam. The second data set (doi:10.1594/PANGAEA.895165) presents the carbon (in kg C m-2) and nitrogen (in kg N m-2) stocks for all the collected cores for the reference depths 0-30 cm, 0-100 cm, 0-150 cm, 0-200 cm. This includes terrestrial as well as lacustrine cores. The third data set (doi:10.1594/PANGAEA.895166) includes 19 radiocarbon dates from five different permafrost cores. The samples were analyzed at the Radiocarbon Laboratory in Poznan, Poland with the accelerated mass spectrometry (AMS) dating method (Goslar et al., 2004). In addition to the AMS dates, the radiocarbon dates were calibrated with the Calib 7.1 software into calibrated years before present and organic carbon accumulation rates were calculated for each of the cores (Stuiver & Reimer, 1993; Stuiver et al., 2017). In addition, a shapefile (Landforms_Teshekpuk_Area) is available including drained thermokarst lake basins of different lake stages, thermokarst lakes (>1 ha), primary surfaces and drainage channels. This landform classification was used in the original study to characterize the chronology of the landscape as well as to calculate landscape carbon and nitrogen stocks.

  • Open Access English
    Authors: 
    Obu, Jaroslav; Lantuit, Hugues; Fritz, Michael; Grosse, Guido; Günther, Frank; Sachs, Torsten; Helm, Veit;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    LiDAR scanning of the Yukon Coast and Herschel Island took place during the AIRMETH (AIRborne studies of METHane emissions from Arctic wetlands) campaigns (Kohnert et al., 2014) on 10 July 2012 and on 22 July 2013. Point cloud data were acquired with a RIEGL LMSVQ580 laser scanner instrument on board the Alfred Wegener Institute's POLAR-5 science aircraft. The laser scanner was operated with a 60° scan angle at a flight height of around 200 m above ground in 2012 and 500 m in 2013. This resulted in a scan width from 200 (2012) to 500 m (2013) and a mean point-to-point distance of 0.5–1.0 m. During the flight on July 10, 2012 the weather was cloudy with a cloud base around 200 m.a.s.l. . Air temperature ranged between 10 and 12 °C with wind speed ranging from 15 to 19 km/h from easterly direction (70–90°). The last recorded storm was on June 17. During the scanning on July 22, 2013, the weather was nearly cloudless with air temperature 9 °C. Wind speed was 15 km/h from easterly direction (60–80°). The last storm before the acquisition occurred on July 2. Raw laser data were calibrated, combined with the post-processed GPS trajectory, corrected for altitude, and referenced to the EGM (Earth Gravitational Model) 2008 geoid (Pavlis et al., 2008). The final georeferenced point cloud data accuracy was determined to be better than 0.15 ± 0.1 m. The loss of accuracy varied along the flight track because of the vertical accuracy of the post-processed GPS trajectory. The GPS datawere acquired in 50Hz resolutionwith aNovatel OEM4 receiver on board POLAR-5. The GPS trajectory was post-processed using precise ephemerides and the commercial software package Waypoint 8.5 (PPP [precise point positioning] processing). For the interpolation to the final DEM an inverse distance weighting (IDW) algorithm was applied using all cloud points within a 10 m radius of each point. Finally, the DEMs from the different acquisition years were interpolated toraster grids of 1 m horizontal resolution in NAD83 UTM zone 7 coordinate system. To quantify vertical change that is significant at the 99% confidence interval, we used three times RMS error procedure by Jaw (2001). Vertical accuracies for both datasets were estimated to be 0.15 m, which results in the threshold of 0.64 m for significant vertical elevation change. The accuracy of the datasets was additionally tested at locations characterized by the presence of anthropogenic features that presumably remain stable and are not affected by vertical movements because of artificial embankments underneath them. The differences between both DEM datasets were assessed along profiles and were within the previously-stated 0.15 m uncertainty.

Advanced search in Research products
Research products
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Include:
The following results are related to European Marine Science. Are you interested to view more results? Visit OpenAIRE - Explore.
20 Research products, page 1 of 2
  • Open Access English
    Authors: 
    Nitze, Ingmar; Fuchs, Matthias; Strauss, Jens; Günther, Frank; Wetterich, Sebastian; Kizyakov, Alexander; Fritz, Michael; Opel, Thomas; Grigoriev, Mikhail N; Maksimov, Georgii T; +2 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | Nunataryuk (773421), EC | PETA-CARB (338335)

    Permafrost thaw and ice wedge degradation lead to drastic landscape changes in the permafrost region. With this data set we investigated the cliff retreat of the Sobo-Sise Cliff (SSC), a high ice-bearing yedoma cliff in the Lena River Delta. The 1,660 m long cliff SSC extends from 72°32'34 N / 128°15'59 E to 72°32'06 N / 128°18'21 E and is located on the Sardakhskaya channel, which is one of the main Lena river branches in the Lena River Delta. Erosion rates for the SSC were determined based on satellite images from different sensors (Corona, Hexagon, Landsat, Planet cube-sat) for the period 1965-2018. Cliff front lines were manually digitized and erosion rates were calculated with the Digital Shoreline Analysis System (DSAS) tool (Himmelstoos et al. 2018). The study Fuchs et al. (2020) (doi:10.3389/feart.2020.00336) shows that the up to 27.7 m high SSC erodes in average 15.7 m yr-1 (2015-2018). During the entire observed time period from 1965-2018, the SSC retreated in average 484 m (ranging from 322 - 680 m). This data set compilation consist of three GIS shapefiles with a corresponding metadata file and a table of the mean annual erosion rates of the yedoma SSC for the time periods 1965-1975, 1975-2000, 2000-2005, 2005-2010, 2010-2015, and 2015-2018, as well as the absolute cliff retreat rates over the entire period 1965-2018, which are derived from remote sensing imagery analyzed with the DSAS tool. In addition, the cliff front lines for each investigated time step are provided as well as the separation between yedoma and alas deposits for each time step. Related trend data for this region, based on Landsat trend analysis are available at: doi:10.1594/PANGAEA.884136 (Nitze, 2018).

  • Open Access English
    Authors: 
    Jongejans, Loeka Laura; Mangelsdorf, Kai; Strauss, Jens;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    These datasets describe a 31.5 m long sediment core taken from beneath thermokarst lake Goltsovoye Lake (71.74515 N, 129.30217 E) on the Bykovsky Peninsula, northeastern Siberia. The thermokarst lake was 510 cm deep. Here, we report the depths from the ice surface as well as from the sediment surface. The first dataset presents biogeochemical and hydrochemical parameters of sediment core PG2412. Biogeochemical analyses include total nitrogen (TN) content, total carbon (TC) content, total organic carbon (TOC) content and stable carbon isotopes (δ13C). δ13C was measured for samples with TOC > 0.1 wt %. Hydrochemical parameters include pore water content, pH and electrical conductivity (EC). The second dataset presents the grain size distribution of sediment core PG2412. The fraction > 1 mm is not included. The third dataset presents the radiocarbon ages from samples from sediment core PG2412. Calibrated and rounded calibrated ages are presented. Calibrations were performed according to Stuiver et al. (2017) using CALIB 7.1 software and the IntCal13 calibration curve. The fourth dataset presents the n-alkane data from samples from sediment core PG2412. Concentrations of n-alkanes in the range n-C23 to n-C33 are given in µg/g sediment and µg/g TOC. From the n-alkane concentrations, we calculated the following indices: average chain length (ACL), carbon preference index (CPI), odd-over-even predominance (OEP), n-Alkane ratio, aquatic plant proxy (Paq) and terrestrial plant proxy (Pwax).

  • Open Access English
    Authors: 
    Angelopoulos, Michael; Overduin, Pier Paul; Jenrich, Maren; Nitze, Ingmar; Günther, Frank; Strauss, Jens; Westermann, Sebastian; Schirrmeister, Lutz; Kholodov, Alexander L; Krautblatter, Michael; +2 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | Nunataryuk (773421), EC | PETA-CARB (338335)

    In July 2017, we collected apparent resistivity data (ohm-m) in a sub-aquatic permafrost environment on the southern coastline of the Bykovsky Peninsula in northeast Siberia. The project goal was to determine the depth to the top of frozen sediment for multiple submerged landscapes. The submerged landscapes included ice-rich Yedoma permafrost, permafrost that had undergone prior thermokarst (Alases), and a former lagoon (i.e. offshore at the lagoon's coastline positions in earlier years). The data was collected with an IRIS Syscal Pro Deep Marine resistivity system that was equipped with a GPS and an echo-sounder to record water depths. The geoelectric cable had an electrode separation of 10 m and the electrodes were arranged in a reciprocal Wenner Schlumberger array. The offset between the first electrode and the boat was approximately 10 m.

  • English
    Authors: 
    Biskaborn, Boris K; Sens, Miriam;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    The dataset describes a 5 m long sediment core taken from beneath thermokarst lake Goltsovoye Lake on the Bykovsky Peninsula, northeastern Siberia. Core location: N 71.74530 E 129.30243. The data represent biogeochemical parameters of sediment core PG2420. Biogeochemical analyses include total organic carbon (TOC) content and stable carbon isotopes (δ13C). δ13C was measured for samples with TOC > 0.1 wt %. The data also include radiocarbon measurements. Calibrated and rounded calibrated ages are presented. Calibrations were performed according to Stuiver et al. (2017) using CALIB 7.1 software and the IntCal13 calibration curve. To all data, the vertical position in the sediment core is given in cm (midth of sample) measured from the ice surface on top of the lake. Depth from ice surface to sediment surface was 510 cm.

  • Open Access English
    Authors: 
    Treat, Claire C; Broothaerts, Nils; Dalton, April S; Dommain, René; Douglas, Tom; Drexler, Judith; Finkelstein, Sarah A; Grosse, Guido; Hope, Geoffrey; Hutchings, Jack A; +20 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: NSF | Collaborative Research: P... (1502891), NSERC , NSF | Collaborative Research: R... (1246190), NSF | Collaborative Research: S... (1107981), NSF | Collaborative Research: P... (1304823), EC | PETA-CARB (338335)

    We present the first synthesis of global peatland extent through the last glacial cycle (130 ka) based on >975 detailed stratigraphic descriptions from exposures, soil pits, and sediment cores. Buried peats are defined as organic-rich sediments overlain by mineral sediments. Also included are deposits rich in wetland macrofossils indicated a local peatland environment. The dataset includes location (lat/long), chronologic information (when available), a description of the buried peat sediment, overlying and underlying sediments, whether geochemical information is available, and the original references.

  • Open Access English
    Authors: 
    Fuchs, Matthias; Grosse, Guido; Strauss, Jens; Günther, Frank; Grigoriev, Mikhail N; Maximov, Georgy M; Hugelius, Gustaf;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    Ice rich Yedoma-dominated landscapes store considerable amounts of organic carbon (C) and nitrogen (N) and are vulnerable to degradation under climate warming. We investigate the C and N pools in two thermokarst-affected Yedoma landscapes - on Sobo-Sise Island and on Bykovsky Peninsula in the North of East Siberia. Soil cores up to three meters depth were collected along geomorphic gradients and analysed for organic C and N contents. A high vertical sampling density in the profiles allowed the calculation of C and N stocks for short soil column intervals and enhanced understanding of within-core parameter variability. Profile-level C and N stocks were scaled to the landscape level based on landform classifications from five-meter resolution, multispectral RapidEye satellite imagery. Mean landscape C and N storage in the first meter of soil for Sobo-Sise Island is estimated to be 20.2 kg C/m**-2 and 1.8 kg N/m**-2 and for Bykovsky Peninsula 25.9 kg C/m**-2 and 2.2 kg N/m**-2. Radiocarbon dating demonstrates the Holocene age of thermokarst basin deposits but also suggests the presence of thick Holocene aged cover layers which can reach up to two meters on top of intact Yedoma landforms. Reconstructed sedimentation rates of 0.10 mm/yr - 0.57 mm/yr suggest sustained mineral soil accumulation across all investigated landforms. Both Yedoma and thermokarst landforms are characterized by limited accumulation of organic soil layers (peat). We further estimate that an active layer deepening by about 100 cm will increase organic C availability in a seasonally thawed state in the two study areas by ~5.8 Tg (13.2 kg C/m**-2). Our study demonstrates the importance of increasing the number of C and N storage inventories in ice-rich Yedoma and thermokarst environments in order to account for high variability of permafrost and thermokarst environments in pan-permafrost soil C and N pool estimates.

  • Open Access English
    Authors: 
    Lenz, Josefine; Wetterich, Sebastian; Jones, Benjamin M; Meyer, Hanno; Bobrov, Anatoly A; Grosse, Guido;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    Permafrost degradation influences the morphology, biogeochemical cycling and hydrology of Arctic landscapes over a range of time scales. To reconstruct temporal patterns of early to late Holocene permafrost and thermokarst dynamics, site-specific palaeo-records are needed. Here we present a multi-proxy study of a 350-cm-long permafrost core from a drained lake basin on the northern Seward Peninsula, Alaska, revealing Lateglacial to Holocene thermokarst lake dynamics in a central location of Beringia. Use of radiocarbon dating, micropalaeontology (ostracods and testaceans), sedimentology (grain-size analyses, magnetic susceptibility, tephra analyses), geochemistry (total nitrogen and carbon, total organic carbon, d13Corg) and stable water isotopes (d18O, dD, d excess) of ground ice allowed the reconstruction of several distinct thermokarst lake phases. These include a pre-lacustrine environment at the base of the core characterized by the Devil Mountain Maar tephra (22 800±280 cal. a BP, Unit A), which has vertically subsided in places due to subsequent development of a deep thermokarst lake that initiated around 11 800 cal. a BP (Unit B). At about 9000 cal. a BP this lake transitioned from a stable depositional environment to a very dynamic lake system (Unit C) characterized by fluctuating lake levels, potentially intermediate wetland development, and expansion and erosion of shore deposits. Complete drainage of this lake occurred at 1060 cal. a BP, including post-drainage sediment freezing from the top down to 154 cm and gradual accumulation of terrestrial peat (Unit D), as well as uniform upward talik refreezing. This core-based reconstruction of multiple thermokarst lake generations since 11 800 cal. a BP improves our understanding of the temporal scales of thermokarst lake development from initiation to drainage, demonstrates complex landscape evolution in the ice-rich permafrost regions of Central Beringia during the Lateglacial and Holocene, and enhances our understanding of biogeochemical cycles in thermokarst-affected regions of the Arctic.

  • Open Access English
    Authors: 
    Angelopoulos, Michael; Westermann, Sebastian; Overduin, Pier Paul; Faguet, Alexey; Olenchenko, Vladimir; Grosse, Guido; Grigoriev, Mikhail N;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    Two separate field excursions were carried out in 2017 to investigate subsea permafrost degradation offshore of the Bykovsky Peninsula in Siberia. In April, four ice cores were drilled offshore to measure sea ice thickness, snow thickness, and water depth. In July, multiple conductivity, temperature, and depths (CTD) sensors were deployed to measure seawater properties like temperature, salinity, and electrical conductivity. Furthermore, electrical resistivity surveys were taken perpendicular to and crossing the shoreline of the Bykovsky Peninsula to estimate the depth of ice-bearing permafrost.

  • Open Access English
    Authors: 
    Fuchs, Matthias; Lenz, Josefine; Jock, Suzanne; Nitze, Ingmar; Jones, Benjamin M; Strauss, Jens; Günther, Frank; Grosse, Guido;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    This data set includes the data for the publication Fuchs et al. (2019), Organic carbon and nitrogen stocks along a thermokarst lake sequence in Arctic Alaska, doi:10.1029/2018JG004591. Impacts of successive thermokarst lake stages on soil organic carbon and nitrogen storage, Arctic Alaska. This study combines terrestrial and lacustrine cores to a depth of two meters for a carbon and nitrogen stock estimation in a heavily thermokarst affected study region as well as describes the landscape chronology of the study area which is characterized by multiple drained thermokarst lake basins of different generations. The first data set (doi:10.1594/PANGAEA.895163) includes the raw laboratory data (TOC, TC, TN, C/N) from the permafrost cores collected at the Teshekpuk Lake Area. The data for the lacustrine cores are published on Pangaea and accessible with the link: https://doi.org/10.1594/PANGAEA.864814 (Lenz et al., 2016). All laboratory analyses on the terrestrial cores were carried out at the Alfred Wegener Institute Potsdam. The second data set (doi:10.1594/PANGAEA.895165) presents the carbon (in kg C m-2) and nitrogen (in kg N m-2) stocks for all the collected cores for the reference depths 0-30 cm, 0-100 cm, 0-150 cm, 0-200 cm. This includes terrestrial as well as lacustrine cores. The third data set (doi:10.1594/PANGAEA.895166) includes 19 radiocarbon dates from five different permafrost cores. The samples were analyzed at the Radiocarbon Laboratory in Poznan, Poland with the accelerated mass spectrometry (AMS) dating method (Goslar et al., 2004). In addition to the AMS dates, the radiocarbon dates were calibrated with the Calib 7.1 software into calibrated years before present and organic carbon accumulation rates were calculated for each of the cores (Stuiver & Reimer, 1993; Stuiver et al., 2017). In addition, a shapefile (Landforms_Teshekpuk_Area) is available including drained thermokarst lake basins of different lake stages, thermokarst lakes (>1 ha), primary surfaces and drainage channels. This landform classification was used in the original study to characterize the chronology of the landscape as well as to calculate landscape carbon and nitrogen stocks.

  • Open Access English
    Authors: 
    Obu, Jaroslav; Lantuit, Hugues; Fritz, Michael; Grosse, Guido; Günther, Frank; Sachs, Torsten; Helm, Veit;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    LiDAR scanning of the Yukon Coast and Herschel Island took place during the AIRMETH (AIRborne studies of METHane emissions from Arctic wetlands) campaigns (Kohnert et al., 2014) on 10 July 2012 and on 22 July 2013. Point cloud data were acquired with a RIEGL LMSVQ580 laser scanner instrument on board the Alfred Wegener Institute's POLAR-5 science aircraft. The laser scanner was operated with a 60° scan angle at a flight height of around 200 m above ground in 2012 and 500 m in 2013. This resulted in a scan width from 200 (2012) to 500 m (2013) and a mean point-to-point distance of 0.5–1.0 m. During the flight on July 10, 2012 the weather was cloudy with a cloud base around 200 m.a.s.l. . Air temperature ranged between 10 and 12 °C with wind speed ranging from 15 to 19 km/h from easterly direction (70–90°). The last recorded storm was on June 17. During the scanning on July 22, 2013, the weather was nearly cloudless with air temperature 9 °C. Wind speed was 15 km/h from easterly direction (60–80°). The last storm before the acquisition occurred on July 2. Raw laser data were calibrated, combined with the post-processed GPS trajectory, corrected for altitude, and referenced to the EGM (Earth Gravitational Model) 2008 geoid (Pavlis et al., 2008). The final georeferenced point cloud data accuracy was determined to be better than 0.15 ± 0.1 m. The loss of accuracy varied along the flight track because of the vertical accuracy of the post-processed GPS trajectory. The GPS datawere acquired in 50Hz resolutionwith aNovatel OEM4 receiver on board POLAR-5. The GPS trajectory was post-processed using precise ephemerides and the commercial software package Waypoint 8.5 (PPP [precise point positioning] processing). For the interpolation to the final DEM an inverse distance weighting (IDW) algorithm was applied using all cloud points within a 10 m radius of each point. Finally, the DEMs from the different acquisition years were interpolated toraster grids of 1 m horizontal resolution in NAD83 UTM zone 7 coordinate system. To quantify vertical change that is significant at the 99% confidence interval, we used three times RMS error procedure by Jaw (2001). Vertical accuracies for both datasets were estimated to be 0.15 m, which results in the threshold of 0.64 m for significant vertical elevation change. The accuracy of the datasets was additionally tested at locations characterized by the presence of anthropogenic features that presumably remain stable and are not affected by vertical movements because of artificial embankments underneath them. The differences between both DEM datasets were assessed along profiles and were within the previously-stated 0.15 m uncertainty.