115 years of sediment deposition in the Urft reservoir (Eifel Mountains, western Germany)

<p>The sediments of the artificial Urft reservoir represent a unique archive of human influence on late Holocene sediment composition. The Urft dam, located in the Eifel Mountains in western Germany, was built between 1900 and 1905. At the time of its construction, the Urft reservoir was the largest reservoir and, with 12 MW, drove the most powerful water storage power plant in Europe. The reservoir has a length of 12 km and, when fully dammed, has a volume of 45.51 million m³ over an area of 2.16 km². The most important inflow is the river Urft. Today, the Urft Lake is completely enclosed by the Eifel National Park.</p><p>Consequently, sediments were deposited in the lake almost undisturbed over the last 115 years. Due to construction work on the Urft dam and the inspection of the 2.7 km long Kermeter Tunnel, which powers the Heimbach hydroelectric power plant, the reservoir was almost completely drained in November 2020. This offered the rare opportunity to sample the deposits in detail and to record the entire lake area photogrammetrically using an Unmanned Aircraft System (UAS). The work was carried out in cooperation between the Water Board Eifel-Rur (WVER) and the Chair of Physical Geography and Geoecology (PGG) at RWTH Aachen University.</p><p>Within the framework of the project, the sediments in the reservoir will be investigated in detail. The comparison of the high-resolution UAS digital elevation models and historical maps will give insights in the amount of sediment deposition in the different areas of the lake during the last 115 years. Geochemical markers will be used to quantify the anthropogenic influence on the sediments in the form of mining-induced pollutant contamination (e.g., heavy metals) and to relate this to the history of use in the catchment area. Another focus will be on recording the microplastics content of the different sediment layers. Since microplastics have only been introduced into the natural system by humans for the last 70 years since the beginning of mass production around 1950, the sediment layers can also be differentiated in terms of time. For these investigations, a total of ten sediment cores with a length of up to 4 m were taken from the deposits.</p>

Meso- to macro-scale landscape modelling with SfM-MVS photogrammetry: a case study from the Urft Lake water reservoir (Eifel Mountains, western Germany)

<p>3D landscape reconstruction derived from imagery acquired by unmanned aerial systems (UAS) is an increasingly applied method within the field of geosciences. Low-cost UAS and subsequent Structure from Motion (SfM) and multi-view stereo (MVS) processing provides the opportunity to study landforms and processes in high detail; for instance mapping of river terraces (Li et al. 2019) or landslide monitoring (Devoto et al. 2020).</p><p>Due to an almost complete drainage of the Urft Lake reservoir in the northern Eifel mountains (W-Germany) in the autumn of 2020, the lake’s entire ground could be surveyed using a low-cost UAS.</p><p>The lake stretches for 12 km and has a maximum impoundment volume of approximately 45 million m³. Its shape is characterized by multiple fluvial bends and steep slopes, which required an elaborated flight layout. A DJI Phantom 4 Pro V2.0 was used. Each flight was carried out in two parallel heights (90 and 120 m), 80° camera inclination, and in double-grid pattern. Five full days of surveying yielded over 6,000 aerial images. Despite the difficulty to access the drained reservoir, 154 evenly distributed ground control points were taken using a Leica RTK dGPS instrument (accuracy <5 cm). SfM-MVS photogrammetric processing was conducted with Agisoft Metashape Professional 1.6, using an optimized workflow based on USGS (2017) and James et al. (2020).</p><p>The resulting 3D model features high accuracy and precision making it suitable for further detailed stationary as well as multi-temporal geomorphologic analyses. The derived DEM features a spatial resolution of <6 cm and will be used to calculate geometric changes of the reservoir body since its construction in 1905; in particular, due to sedimentation and mass movements along the hillslopes. Moreover, the products can be used to study the anthropogenic influences of the water reservoir on the fluvial morphology of the Urft.</p><p> </p><p>References:</p><p>Devoto, S., Macovaz, V., Mantovani, M., Soldati, S., Furlani, S., 2020. Advantages of Using UAV Digital Photogrammetry in the Study of Slow-Moving Coastal Landslides.  Remote Sensing 2020, 12, 3566. https://doi.org/10.3390/rs12213566  </p><p>James, M.R., Antoniazza, G., Robson, S., Lane, S.N., 2020. Mitigating systematic error in topographic models for geomorphic change detection: accuracy, precision and considerations beyond off-nadir imagery. Earth Surface Processes and Landforms 45, 2251–2271. https://doi.org/10.1002/esp.4878</p><p>Li, H., Lin, C., Wang, Z., Yu, Z., 2019. Mapping of River Terraces with Low-Cost UAS Based Structure-from-Motion Photogrammetry in a Complex Terrain Setting. Remote Sensing 2019, 11, 464. https://doi.org/10.3390/rs11040464</p><p>United States Geological Survey (USGS), 2017. Unmanned Aircraft Systems Data Post Processing: Structure-from-Motion Photogrammtery. Section 2 – MicaSense 5-band MultiSpectral Imagery. USGS National UAS Project Office. https://uas.usgs.gov/nupo/pdf/PhotoScanProcessingMicaSenseMar2017.pdf (Retrieved: 24 July 2020).</p>

Mofette Vegetation as an Indicator for Geogenic CO2 Emission: A Case Study on the Banks of the Laacher See Volcano, Vulkaneifel, Germany

A geogenic CO2 emitting site (mofette U1) at the banks of the Laacher See, Eifel Mountains, was chosen to study the relationship between heavy postvolcanic soil degassing and vegetation during spring season. To test any interrelation between soil CO2 degassing and vegetation, soil chemism (pH, water content, conductivity, and humus content) and vegetation studies (number of species, plant-soil coverage) were performed. Geogenic soil degassing patterns of carbon dioxide and oxygen were clearly inhomogeneous, resembling soil porosity and distinct permeation channels within the soil. CO2 concentrations ranged from zero to 100%. Soil CO2 increased, while soil oxygen decreased with increasing soil depth. There was a reasonable correlation between CO2 degassing and soil pH as well as soil conductivity. Soil organic matter (SOM) resembled soil water distribution. The number of plant species (from a total of 69 species) as well as plant coverage strongly followed geogenic CO2 degassing. The total number of growing species was highest in low CO2 soils (max. 17 species per m2) and lowest at high CO2-emitting sites (one species per m2). Plant coverage followed the same pattern. Total plant coverage reached values of up to 84% in slightly degassing soils and only 5-6% on heavy CO2-venting sites. One plant species proved to be highly mofettophilic (marsh sedge, Carex acutiformis) and strictly grew on CO2 degassing sites. Most other species like grove windflower, spring fumewort, fig buttercup, wood bluegrass, addersmeat, and common snowberry showed a mofettophobic behavior and strictly avoided degassing areas. Specific plant species can thus be used to detect and monitor pre- or postvolcanic CO2 degassing.

Report on the Discovery of Fossil Mares with Preserved Uteroplacenta from the Eocene of Germany

I report on the discoveries of three pregnant mares from the middle Eocene of Germany that contain remains of fetuses still wrapped in the fossilized uteroplacenta. These are the first and up to now only discoveries of this kind. One specimen comes from the Eckfeld Maar (Eifel Mountains). It is 44 million years of age. The other two were discovered at Grube Messel and are 48 million years old. These are the oldest fossil uteroplacentae known so far. Their morphology corresponds to recent homologues. Presumably, the uteroplacenta developed as part of the propagation system of mammals during the Palaeocene, perhaps already during the late Mesozoic.

Noonkanbahite, BaKNaTi2(Si4O12)O2, a new mineral species: description and crystal structure

Noonkanbahite, ideally BaKNaTi2(Si4O12)O2, is described as a new mineral species. At Liley [Löhley], Eifel Mountains, Germany (the holotype locality), it occurs as sprays of prismatic crystals (up to 8 mm) or single prismatic crystals (up to 4 mm) on walls of cavities in alkaline igneous rocks. At Murun, Siberia, Russia, noonkanbahite forms coarse lamellar crystals up to 0.05 cm × 0.7 cm × 1.5 cm embedded in kalsilite syenite. Noonkanbahite is brittle, H = 6, Dobs. = 3.39(1), Dcalc. = 3.49 g/cm3, has a vitreous lustre and does not fluoresce in ultraviolet light. It has poor cleavage on {010} and {100} and weak parting on {011}. Noonkanbahite is biaxial positive with 2Vobs. = 75(2)°, 2Vcalc. = 72.7(9)°, α 1.730(5), β 1.740(5) and γ 1.765(5), dispersion is medium, r < v. In transmitted plane-polarized light, noonkanbahite is strongly pleochroic, with X colourless, Y yellowish, Z straw-yellow; X = a, Y = b, Z = c. Noonkanbahite is orthorhombic, space group Imma, a = 8.0884(4), b = 10.4970(5), c = 13.9372(6) Å, V = 1183.3(1) Å3, Z = 4. The strongest ten X-ray diffraction lines in the powder pattern [d in Å (I)(hkl)] are: 2.907(100)(222), 8.353(50)(001), 3.196(50)(220), 2.097(50)(242), 2.241(40)(215), 2.179(40)(035), 3.377(30)(031), 2.694(30)(015), 2.304(30)(233), and 1.564(30)(064). Electron microprobe analysis gives SiO2 37.82, TiO2 15.54, ZrO2 0.42, Nb2O5 3.18, Al2O3 0.17, Fe2O3 (recalculated from FeO) 5.63, MnO 0.32, MgO 0.53, BaO 20.60, CaO 1.36, K2O 5.32, Na2O 6.14, F 0.78, H2O 0.58, sum 98.39 wt.%, (H2O determined by SIMS). The formula unit, calculated on the basis of 14 anions (O+OH+F), is (Ba0.85K0.13)Σ0.98(K0.59Na0.26Ca0.15)Σ1.00Na(Ti1.23Fe0.453+Nb0.15Mg0.08Mn0.03Zr0.02Al0.01)Σ1.97 (Si3.99Al0.01O12)(O1.33OH0.41F0.26)Σ2.00, Z = 4.The crystal structure was refined to R1 = 2.8% for 970 unique (F0 > 4σF) reflections collected on a Bruker single-crystal P4 diffractometer with a CCD detector and MoKα X-radiation. The crystal structure of noonkanbahite is isostructural with that of batisite, ideally BaNa2Ti2(Si4O12)O2, and scherbakovite, ideally K2NaTi2(Si4O12)O(OH). There are two octahedrally coordinated sites, M(1) and M(2), occupied by (Ti1.23Fe0.453+Nb0.15Mg0.08Mn0.03Zr0.02Al0.01), ideally Ti2 a.p.f.u. There are three interstitial A sites, [9]A(1), [8]A(2) and [6]A(3), occupied by Ba, K and Na, respectively. Si tetrahedra and M octahedra form a framework with interstitial cages occupied by Ba, K and Na atoms at the A sites. Noonkanbahite, BaKNaTi2(Si4O12)O2, is a K analogue of batisite, BaNa2Ti2(Si4O12)O2, and a Ba analogue of shcherbakovite, K2NaTi2(Si4O12)O(OH).

The new era of large paraboloid antennas: the life of Prof. Dr. Otto Hachenberg

Seldom does a scientist get an opportunity in his lifetime to build an instrument that remains unchallenged as the world’s no. 1 for 30 years. The Effelsberg 100- m radio telescope, constructed under the direction of Prof. Dr. Otto Hachenberg, was the world’s largest fully steerable paraboloid antenna since its inauguration in 1971. The radio telescope in a valley in the Eifel mountains near Bonn was constructed with a remarkably precise surface and excellent pointing characteristics. Only in 2001 the 100-m × 110-m Green Bank Telescope became operational and marginally surpassed Effelsberg’s performance. The Effelsberg telescope is still fully operational in 2002 and looking forward to an exciting future. It is a memorial to the ingenuity of a person who influenced the development of German radio astronomy.