ALBERT

Description: Recent mobilisation of soil organic matter (SOM) in permafrost of the northern high latitudes is thought to have a significant impact on the carbon balance in the atmosphere. However, the environmental processes which influence SOM accumulation and remobilisation still need to be investigated more accurately. This study investigates the quantity and quality of SOM on Herschel Island in the western Canadian Arctic in relation to various landscape characteristics. To reach this goal, soil moisture, total organic carbon (TOC) and total nitrogen (TN) contents, stable carbon isotopes (∂¹³C) and TOC/TN ratios (C/N) were determined on 128 samples from twelve sediment cores reaching up to 250 cm depth. Drilling locations were chosen based on morphology, vegetation and soil properties and supported by satellite imagery and air photos. Seasonal thaw depths (active layer depths) correlate with ground disturbance and vegetation cover and lie between 20 and 100 cm. Well-preserved SOM is accumulated in the active layer and subjacent ice-rich permafrost of wet polygonal tundra. Uplands, hummocky tussock tundra and alluvial fans cover more than 50 % of the island and show heterogeneous SOM storage characteristics with considerable TOC contents being limited to the active layer. Disturbed areas with slope gradients greater than 6° show strong SOM degradation with low TOC contents throughout the active layer and permafrost strata. Linear regression and principal component analysis (PCA) shows that a decreasing SOM content is driven by increasing ground disturbance and reduced vegetation cover. Improved drainage decreases the preservation of SOM in the active layer. Future deepening of the active layer because of increasing temperatures and ground disturbance will remobilise SOM stored in ice-rich permafrost. This might increase carbon dioxide and methane emissions from permafrost landscapes.

Description: Changes in high latitude ocean gateways and atmospheric CO2 are thought to be main drivers of Cenozoic climate evolution during the last 65 million years. However as yet, especially the link between climate changes and the opening history of the North Polar Seas via the subsidence of the Greenland-Scotland Ridge is poorly understood. Here we use a coupled ocean–atmosphere general circulation model for early Miocene boundary conditions to reveal a threshold behaviour for the ventilation of the North Polar Seas controlled by the Greenland-Scotland Ridge subsidence. Our model simulations show that a deepening of the ridge from 200 to 300 meters below sea-level induces major reorganizations in North Atlantic-Arctic Ocean circulation with an abrupt regime shift from restricted estuarine conditions to a bi-directional flow regime similar to today. Close to critical gateway depths, additional scenarios with different atmospheric CO2 concentrations indicate that realistic Oligocene-Miocene CO2 changes actively modulate the transition between the two circulation regimes via the impact of the atmospheric hydrological cycle. Taking uncertainties in timing into account this suggest that tectonic changes starting at ~33-30 Myrs controlled the circulation of the Nordic Seas. Thereafter superposed changes in CO2 delayed an abrupt transition to a modern prototype North Atlantic-Arctic exchange by millions of years until CO2-levels finally dropped to preindustrial levels at ~25-24 Myrs. This concept and the associated mechanism bridges tectonic processes with much shorter time-scales in the coupled atmosphere-ocean system that differ by three orders of magnitude, which provides an unanticipated new perspective on abrupt climate changes during the Cenozoic era.

Description: In summer 2017, the ICDP SUSTAIN project (Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes), drilled three cored boreholes (Table 1) through Surtsey at sites ≤10 m from a cored hole obtained in 1979. Drilling through the still hot volcano was carried out with an Atlas Copco CS1000 drill rig, whose components were transported by helicopter to Surtsey and re-assembled on site. The first vertical borehole, SE-02a, was cored in HQ diameter to 152 meters below surface (m b.s.) during August 7-16. It was terminated due to borehole collapse. A second vertical (SE-02b) cored borehole was then drilled in HQ diameter to 192 m during August 19-26. Wireline borehole logging in SE-02b was performed August 26. The anodized NQ-sized aluminum tubing of the Surtsey Subsurface Observatory was installed in SE-02b to 181 m depth on August 27. A third borehole, SE-03, angled 35° from vertical and directed 264°, was drilled from August 28 to September 4 and reached a measured depth of 354 m (~290 m vertical depth) under the eastern crater. The core is HQ diameter to a measured depth of 213 m and NQ diameter from 213-354 m measured depth. The core traverses the deep conduit and intrusions of the volcano to a total vertical depth of 290 m b.s. Seawater drilling fluid for boreholes SE-02a and SE-02b was filtered and doubly UV-sterilized at the drill site. No mud products were employed while coring SE-02a, while small amounts of attapulgite mud were used in SE-02b and SE-03. Core samples for geochemical analyses of pore water and microbiological investigations were collected on site from all three boreholes. About 650 m of core was transported by helicopter to Heimaey, 18 km northeast of Surtsey, to a processing laboratory where the core was scanned, documented, and described. Additional core processing has taken place at the Náttúrufraedistofnun Íslands, the Icelandic Institute of Natural History in Gardabaer, where both the 1979 and 2017 cores are stored.

Description: On a beautiful summer day Emma and Steven want to have fun at their favourite lake. However, a mysterious situation thwarts their plans. This leads the two friends on an unexpected quest ... Join Emma and Steven as they explore the vast, intriguing and efficient world of stable isotopes: What are isotopes? How do isotopes work? And last but not least, how can isotopes help Emma and Steven to finally answer the question: Who poisoned Family Mole?

Description: Length: 32 min What forms the landscapes of the Earth with its mountains, rivers, soils, the places we live in? Is Earth’s surface shaped when rocks are uplifted by geologic forces, and are then destroyed by rain, ice, and wind; or do plants with their roots, animals that dig into soil and the vast number of microorganisms shape the landscapes? Watch the scientists of the German-Chilean “EarthShape” project study these questions along a fascinating landscapes in Chile, and in their home laboratories. A science movie designed and produced by Friedhelm von Blanckenburg from GFZ Potsdam, Germany, Kirstin Übernickel from Universität Tübingen, and Wolfgang Dümcke from Filmbüro Potsdam, Germany, within the DFG-funded research network “EarthShape – Earth Surface Shaping by Biota” which is coordinated by Todd Ehlers (Universität Tübingen) und Friedhelm von Blanckenburg (GFZ Potsdam).

Description: The GIZ Transboundary Water Management in Central Asia programme supports Tajik-Kyrgyz cooperation on the shared Isfara river basin by means of sustainable basin planning and management through capacity building. In addition, the rehabilitation of small-scale infrastructure and automatised flow measurement systems ensure a safe and fair allocation of water resources. As a result, improved water management and infrastructure in the Isfara River contribute to better information and water availability for more than 200,000 agricultural water users across both countries. Alongside already established methods of transboundary cooperation in the basin, which has complicated boundary issues, the hereinafter described measures counteract latent tensions among Tajik and Kyrgyz communities over the limited resource of arable land, which is closely linked to water. The GIZ Transboundary Water Management in Central Asia programme is implemented on behalf of the German Federal Foreign Office and cofunded by the European Union.

Description: Deliverable D5.2 presents the experimental outcome of jetting experiments at simulated reservoir conditions. Different rock types are tested under various conditions with the use of three different types of test bench. At first jetting experiments are conducted under submerged conditions in order to derive a better understanding of the governing erosion mechanism. Therefore pitting tests are combined with PIV measurements in order to derive and explain the erosion pattern of the occurring cavitation erosion and why the rock is more like to be eroded by the stagnation pressure of the impinging jet. Second, jetting experiments under pressure controlled conditions are performed. Rate of penetrations (ROP) of up to 100 m/h can be achieved which proofs the successful application of RJD technology especially in sand stone reservoir rock types. Especially the rotating nozzle design bears the highest potential for jetting operations where the static nozzle designs tend to fail, especially when pore pressure increases. The third experimental series under application of a bi- axial stress field show that the current RJD technology, as being used by project partner WSG, is not able to penetrate harder sandstone rock types (e.g. Dortmund sandstone) when field operating conditions are applied. The induced stress in the specimen does not initiate or enhance ROP. A second experiment thereby shows that higher nozzle exit speeds can lead to massive breakouts. Fourth, experiments are performed under a tri-axial stress field in collaboration with TU DELFT. Rock cubes are tested under different and very severely stress regimes while jetting into them. Compared to tests at atmospheric conditions it can be stated that the application of a stress field does not enhance the erosion of rock. At last experiments are conducted with the project partner WSG in order to determine the jetability of the Icelandic Basalt rock type and Icelandic inter basalt sediment layer. The experiments show that already higher pump pressures result in higher jetting performance, hence making them jetable as previously not expected. Furthermore the experiments approved the feasibility of the planned field test in Iceland when the soft sediment layer is the target zone. All in all the experiments conducted with the RJD technology show different results at simulated reservoir conditions compared to those at atmospheric which are described in deliverable D5.1 (Hahn & Wittig, 2017). Therefor, further testing at conditions representing the reservoir conditions more closer are needed in order to better understand and analyze the jetting process downhole.

Description: In this deliverable, the objectives of the Imperial College team are to consider jetted boreholes in the context of conventional borehole wall-rock stability analysis and to utilise an in-house advanced combined finite-discrete element code to examine the wall-rock failure process for jetted holes. The geomechanical modelling of Lateral Stability in D7.2 presented here is in addition to the main focus on modelling the water-jetting breakdown of the rock itself, reported in D7.1.

Description: The aim of this research is to investigate the failure mechanism for different types of rock in the context of water jet drilling and to predict the jet-ability or assess the radial jet drilling (RJD) performance prior to drilling and at the well petrophysical analysis stage. The main approach is to numerically simulate the water jet drilling for different types of rock using ICL’s in-house fluid-solid coupling codes. The rock properties, CT-scan data and jetting results obtained from D4.1 (Bakker et al., 2018) and D5.1 (Hahn et al., 2017) provide a good foundation for the related numerical results.