News Article | November 24, 2016
Geothermal Alliance Bavaria: Three universities team up to study the utilisation of geothermal energy MUNICH, 24-Nov-2016 — /EuropaWire/ — Temperatures in the Earth’s interior reach thousands of degrees Celsius. Geothermal technology makes use of this energy. It has enormous potential particularly in Bavaria. In response to an initiative of the Bavarian state government, three universities have formed the Geothermal Alliance Bavaria (GAB), headed by the Technical University of Munich (TUM). In an interview, project coordinator Dr. Katharina Aubele of TUM’s Munich School of Engineering discusses the benefits of this form of renewable energy and explains where more research is needed. Can you explain in simple terms what geothermal energy is all about? Aubele: “Geothermal” comes from the ancient Greek words for “Earth” and “heat”. And that sums it up: it uses the heat stored in the Earth’s interior. Temperatures there are currently in the range of five to six thousand degrees Celsius. Naturally, the closer you are to the surface, the cooler the temperatures become. The rise in temperature with increasing depth, known as the geothermal gradient, averages 3°C for every hundred metres. We distinguish between near-surface and deep geothermal applications. In near-surface applications, holes are drilled to a depth of up to 400 metres. After that, the deep applications begin. What are the differences? Aubele: Near-surface applications generally serve as a local energy source for heating or hot water in single family homes or office buildings with the aid of heat pumps. That means that an additional energy source is needed in order to raise the relatively low water temperatures in the geothermal collectors to where the hot water circulation in a building can be heated, for example. In most deep applications, temperatures are reached that allow direct use as an energy source. At temperatures above 100°C, it’s also possible to generate electric power. In the Geothermal Alliance we are working exclusively with deep geothermal applications. How did the GAB come about? Aubele: The Geothermal Alliance Bavaria was established as an interdisciplinary research project under an initiative of the Bavarian state government. The consortium is made up of the Friedrich Alexander Universität (FAU) in Nuremberg, the University of Bayreuth and TUM. The alliance is working in close cooperation with operators of geothermal facilities. “GEOLOGICAL CONDITIONS IN BAVARIA ARE VERY FAVOURABLE” Why is Bavaria’s geology so well suited for deep geothermal applications? Aubele: As a rule, geothermal applications in Bavaria involve hydrothermal set-ups. That means pumping high-temperature water that is present at great depths. The geological conditions in Bavaria are very favourable for this approach. Below the surface we have Southern German Molasse Basin deposits. This is the foreland basin that has formed north of the Alpine mountain belt. Below the Molasse Basin deposits, there is a deep aquifer known as the Malm that dates back to the Late Jurassic epoch. The limestone formations in the aquifer are subject to karstic erosion, which tends to produce large hollow spaces that are conducive to excellent water flow. The Alps are pushing down on this layer, causing even hotter temperatures. That means that there is a permeable layer at a depth of 3000 to 5000 metres. When a hole is drilled down to that layer and the hot groundwater is pumped to the surface, it can be used directly. Of the 33 deep geothermal installations in Germany, 21 are in Bavaria. How is the water pumped to the surface and utilised? Aubele: A hydrothermal set-up generally takes the form of a doublet. That means that two wells are drilled. The first is the production well, through which the hot groundwater is pumped to the surface, in most cases using submersible centrifugal pumps. If the water reaching the surface is not hot enough to generate electric power, it is used for district heating via heat exchangers. The cooled thermal water is returned to the reservoir through the injection well to maintain equilibrium in the aquifer. The thermal water is pumped to the surface in a closed loop and does not come into contact with the atmosphere. “COMPLETELY INDEPENDENT OF THE TIME OF DAY AND THE SEASONS” What advantages does geothermal energy offer over other energy sources? Aubele: It can be considered a form of renewable energy. Naturally we remove a little heat from the Earth’s crust over extended periods. However, when we consider that the Earth is 4.6 billion years old and the core temperature is still several thousand degrees Celsius, it’s clear that this cooling process will have no impact over the course of our lifetime or even our grandchildren’s lifetime. Another advantage of geothermal energy is that, in contrast to solar or wind energy, it is completely independent of the time of day and the seasons. The objective of the GAB is to conduct research on open questions related to the use of geothermal energy. Can you give us some examples of planned projects? Aubele: One area of research is scaling. There is a lot of hard water here in Bavaria. When it is pumped to the surface, the drop in temperature as well as pressure causes sedimentation of the dissolved minerals. The main problem is then the lime deposits throughout the system, which of course damage the seals, standpipes and pumps. Descaling is a time-consuming and costly process for system operators. The GAB will study the mechanisms behind scaling in order to develop successful approaches for avoiding it. In addition, we were also recently selected by the German Federal Environment Agency for a project to study how to integrate geothermal electric power into the electricity market. “YOU HAVE TO HAVE THE PUBLIC ON YOUR SIDE” There are also plans for a degree programme in geothermal energy. Aubele: The geothermal/geoenergy programme will be set up within the framework of the GAB, and is due to begin in the winter semester of 2017/18. It will be coordinated by FAU, which will also run most of the lectures, labs and seminars. The course is intended above all for engineers and geoscience students. However, it will also cover skills that are important especially for geothermal science and renewable energy. Courses of this kind are relatively rare in Germany at the moment. Along with scientific and geoscience disciplines, students will acquire a knowledge of business, regulatory aspects of renewable energy, and civic participation issues. Civic participation is also a topic of interest for the GAB … Aubele: To succeed in establishing this kind of technology, you have to have the public on your side. There are always concerns. For example, people wonder: What will happen below ground? Will my property sink? Will my house fall into a hole? These fears must be taken seriously. Another fear is that it might trigger earthquakes. In Bavaria we have the good fortune of living in a region where there is not much pre-existing geological tension below ground. There are also plans to set up a monitoring network for municipal areas to address these concerns. All in all, it has been my experience that many concerns can be clarified by being open and honest and explaining everything. Further information: The Geothermal Alliance Bavaria (GAB) was established to investigate scientific phenomena in the field of deep geothermal energy and as a networking platform for facility operators to share their experiences. The alliance consists of seven research chairs, junior research groups, working groups of the Technical University of Munich (TUM), GeoZentrum Nordbayern at FAU Nuremberg-Erlangen, and one chair at the University of Bayreuth. The Munich School of Engineering(MSE) at TUM is responsible for project coordination. The cooperative research project is supported by the Bavarian Ministry for Education, Science and the Arts.
Westphal H.,University of Bremen |
Hilgen F.,Institute of Paleoenvironments and Paleoclimate Utrecht |
Munnecke A.,GeoZentrum Nordbayern
Earth-Science Reviews | Year: 2010
A manual is presented to assist in assessing the suitability of individual calcareous rhythmites for high-resolution stratigraphic applications and orbital dating. While the astrochronological approach offers an unprecedented high temporal resolution for stratigraphy, caution is required to carefully choose suitable rhythmites for the analysis. Diagenesis is known to distort or mimic primary signals in particular in carbonate rhythmites. To keep orbital dating a reliable method, the choice of sedimentary successions has to be undertaken with utmost scrutiny. Here, we review and evaluate the methods that have been used for assessing the record of primary signals in calcareous rhythmites. The goal is to provide the orbital stratigrapher with tools for a straightforward and systematic assessment of such successions. © 2010 Elsevier B.V.
Munnecke A.,GeoZentrum Nordbayern |
Zhang Y.,CAS Nanjing Institute of Geology and Palaeontology |
Liu X.,CAS Nanjing Institute of Geology and Palaeontology |
Cheng J.,CAS Nanjing Institute of Geology and Palaeontology
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2011
About 500 samples from 11 Ordovician sections in South China have been analysed for their δ13Ccarb composition. Four sections are located in the Yangtze platform region, the remaining seven sections in the Jiangnan slope region. The sections span more or less the entire Ordovician, but the sample resolution in its lower part (Tremadocian to Dapingian) is lower than in its upper part (Darriwilian to Hirnantian). Overall, the data show a good correlation with the published global isotope curve. At the Cambrian-Ordovician boundary positive values are observed. In the succeeding Tremadocian the values decrease and remain negative into the early Floian. In the late Floian, the values increase to slightly positive. The correlation of Dapingian rocks between the Yangtze and the Jiangnan regions is somewhat problematic which might be due to high siliciclastic input in the Yangtze section. In the Darriwilian a small positive excursion is observed in the Yangtze platform area, however, it is missing in the Jiangnan slope area. This excursion probably correlates with the mid-Darriwilian excursion (MDICE) reported from Baltoscandia. Both chemostratigraphy and conodont biostratigraphy indicate a possible gap between the Shihtzupu Formation and the Pagoda Formation, i.e. most of the Sandbian is probably not represented in the Upper Yangtze region. The earliest Katian is characterised by a pronounced positive excursion correlating with the well-known global Guttenberg excursion (GICE). In the late Katian at least one additional positive excursion was determined. The precise biostratigraphy, however, is not clear, and therefore it is not known which of the known four to five remaining Katian δ13C excursions identified in Baltica correlate(s) with the one(s) observed in the present study, and further biostratigraphic study is required. The lower part of the Hirnantian excursion (HICE) is probably not preserved, with only small remnants of the HICE observed near the base of the Kuanyinchiao Bed. © 2011 Elsevier B.V.
John T.,University of Munster |
Gussone N.,University of Munster |
Podladchikov Y.Y.,University of Lausanne |
Bebout G.E.,Lehigh University |
And 6 more authors.
Nature Geoscience | Year: 2012
At subduction zones, oceanic lithosphere that has interacted with sea water is returned to the mantle, heats up during descent and releases fluids by devolatilization of hydrous minerals. Models for the formation of magmas feeding volcanoes above subduction zones require largescale transport of these fluids into overlying mantle wedges 1-3. Fluid flow also seems to be linked to seismicity in subducting slabs. However, the spatial and temporal scales of this fluid flow remain largely unknown, with suggested timescales ranging from tens to tens of thousands of years 3-5. Here we use the Li-Ca-Sr isotope systems to consider fluid sources and quantitatively constrain the duration of subduction-zone fluid release at ∼ 70 km depth within subducting oceanic lithosphere, now exhumed in the Chinese Tianshan Mountains. Using lithium-diffusion modelling, we find that the wall-rock porosity adjacent to the flowpath of the fluids increased ten times above the background level. We show that fluids released by devolatilization travelled through the slab along major conduits in pulses with durations of about ∼ 200 years. Thus, although the overall slab dehydration process is continuous over millions of years and over a wide range of pressures and temperatures, we conclude that the fluids produced by dehydration in subducting slabs are mobilized in short-lived, channelized fluid-flow events. © 2012 Macmillan Publishers Limited. All rights reserved.
Munnecke A.,GeoZentrum Nordbayern |
Calner M.,Lund University |
Harper D.A.T.,Statens Naturhistoriske Museum Geologisk Museum |
Servais T.,GeoZentrum Nordbayern |
Servais T.,French National Center for Scientific Research
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010
Following the Cambrian Explosion and the appearance in the fossil record of most animal phyla associated with a range of new body plans, the Ordovician and Silurian periods witnessed three subsequent major biotic events: the Great Ordovician Biodiversification Event, the end-Ordovician extinction (the first animal extinction and second largest of the five mass extinctions of the Phanerozoic), and the Early Silurian post-extinction recovery. There are currently no simple explanations for these three major events. Combined extrinsic (geological) and intrinsic (biological) factors probably drove the biodiversifications and radiations, and the appearance and disappearance of marine habitats have to be analysed in the frame of changing palaeogeography, palaeoclimate and sea-water chemistry. The present paper reviews the relationships of the three biotic events to chemical and physical processes occurring in the ocean and atmosphere during the Ordovician and Silurian, including sea-level changes, geochemical proxies (δ13C, δ18O, 87Sr/86Sr) of the ocean waters, and the evolution of the atmosphere (oxygen and carbon dioxide content). © 2010 Elsevier B.V.
Just J.,Geozentrum Nordbayern |
Schulz B.,TU Bergakademie Freiberg |
de Wall H.,Geozentrum Nordbayern |
Jourdan F.,Curtin University Australia |
Pandit M.K.,University of Rajasthan
Gondwana Research | Year: 2011
The in-situ "chemical" Th-U-Pb dating of monazite with the electron microprobe is used to unravel the Neoproterozoic tectono-thermal history of the "Erinpura Granite" terrane in the foreland of the Delhi Fold Belt (DFB) in the NW Indian craton. These granitoids are variably deformed and show effects of shearing activity. Monazites from the Erinpura granitoids recorded two main events; (1) protolith crystallization at 863 ± 23. Ma and (2) recrystallization and formation of new Th-poor monazite at 775 ± 26. Ma during shear overprint. Some components of the Erinpura granitoids, such as the Siyawa Granite and granites exposed near Sirohi town, show evidence of migmatization. This migmatization event is documented by anatexis and associated monazite crystallization at 779 ± 16. Ma. The age data indicate an overlap in timing between anatectic event and ductile shear deformation. The end of the tectono-thermal event in the Sirohi area is constrained by a 736 ± 6. Ma Ar-Ar muscovite age data from the ductile shear zone. © 2010 International Association for Gondwana Research.
Beuck L.,GeoZentrum Nordbayern |
Freiwald A.,GeoZentrum Nordbayern |
Taviani M.,CNR Marine Science Institute
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2010
This study focuses on the carbonate biodegradation processes of deep-water scleractinians from off Apulia at Santa Maria di Leuca (SML) in the Ionian Sea, including living colonies of Lophelia pertusa, Madrepora oculata and Desmophyllum dianthus. The corallites were grouped into three zones: the live zone, edge zone and dead zone. In total, 13 trace types were encountered and are attributed to borings of sponges (3), fungi (6), foraminifers (2), bacteria (1) and annelids (1). Their relative spatial appearance within the host skeletons led to the distinction between six succession stages of bioerosion. The first endobiontic traces are exclusively produced by bacteria and fungi and are already present in the edge zone, which could be attributed to their fast growth rates and/or temporal exposure of the bare skeleton to the water column. In D. dianthus the entire ichnospecies assemblage has been documented within the first 1.9 cm below the live zone and represents the most condensed bioerosion succession amongst the coral species studied. The strongest degradation of corallites at SML is made by boring sponges, which can excavate 70% or more of the skeleton. The finding of a unilateral condensed succession of bioerosion stages may be linked to prevailing unidirectional strong currents. A comparison of the present ichnocoenosis with bioerosion studies from the Eastern Atlantic evidences a reduced ichnodiversity in Ionian Sea bathyal corals. © 2009 Elsevier Ltd. All rights reserved.
Jarochowska E.,GeoZentrum Nordbayern |
Munnecke A.,GeoZentrum Nordbayern |
Kozlowski W.,University of Warsaw
GFF | Year: 2014
The Homerian (middle Silurian) Mulde Event is an extinction event affecting hemipelagic organisms associated with a positive stable carbon isotope excursion, and an increased proliferation of microbial deposits. The Event is recorded in the Bagovytsya section (Podolia, Ukraine), representing a carbonate ramp setting in the East European Craton, and recording the δ13Ccarb excursion with values reaching +5.17%. The associated facies include oncolitic beds, mud-mounds and thrombolitic buildups dominated by cyanobacteria and microproblematica with proposed bacterial affinities. The associated faunal assemblage includes a high proportion of rostroconchs and abundant gastropods and trilobites. The co-occurrence of grazing organisms and microbial sediments suggests that the microbial preservation was not caused by decreased grazing rates. © 2014 © 2014 Taylor & Francis.
Teichert S.,GeoZentrum Nordbayern |
Freiwald A.,Senckenberg Institute
Biogeosciences | Year: 2014
In this study we present a comparative quantification of CaCO3 production rates by rhodolith-forming coralline red algal communities situated in high polar latitudes and assess which environmental parameters control these production rates. The present rhodoliths act as ecosystem engineers, and their carbonate skeletons provide an important ecological niche to a variety of benthic organisms. The settings are distributed along the coasts of the Svalbard archipelago, being Floskjeret (78° 18' N) in Isfjorden, Krossfjorden (79°08' N) at the eastern coast of Haakon VII Land, Mosselbukta (79 °53' N) at the eastern coast of Mosselhalvøya, and Nordkappbukta (80 °31' N) at the northern coast of Nordaustlandet. All sites feature Arctic climate and strong seasonality. The algal CaCO3 production rates were calculated from fuchsine-stained, presumably annual growth increments exhibited by the rhodoliths and range from 100.9 g (CaCO3) m-2 yr-1 at Nordkappbukta to 200.3 g (CaCO3) m-2 yr-1 at Floskjeret. The rates correlate to various environmental parameters with geographical latitude being the most significant (negative correlation, Combining double low line 0.95, Combining double low line 0.0070), followed by the duration of the polar night (negative correlation, Combining double low line 0.93, Combining double low line 0.0220), the duration of the sea ice cover (negative correlation, Combining double low line 0.87, Combining double low line 0.0657), and the annual mean temperature (positive correlation, Combining double low line 0.48, Combining double low line 0.0301). This points out sufficient light incidence to be the main control of the growth of the examined coralline red algal rhodolith communities, while temperature is less important. Thus, the ongoing global change with its rising temperatures will most likely result in impaired conditions for the algae, because the concomitant increased global runoff will decrease water transparency and hence light incidence at the four offshore sites. Regarding the aforementioned role of the rhodoliths as ecosystem engineers, the impact on the associated organisms will presumably also be negative. © Author(s) 2014. CC Attribution 3.0 License.
Teichert S.,GeoZentrum Nordbayern
Scientific Reports | Year: 2014
Rhodoliths are coralline red algal assemblages that commonly occur in marine habitats from the tropics to polar latitudes. They form rigid structures of high-magnesium calcite and have a good fossil record. Here I show that rhodoliths are ecosystem engineers in a high Arctic environment that increase local biodiversity by providing habitat. Gouged by boring mussels, originally solid rhodoliths become hollow ecospheres intensely colonised by benthic organisms. In the examined shelf areas, biodiversity in rhodolith-bearing habitats is significantly greater than in habitats without rhodoliths and hollow rhodoliths yield a greater biodiversity than solid ones. This biodiversity, however, is threatened because hollow rhodoliths take a long time to form and are susceptible to global change and anthropogenic impacts such as trawl net fisheries that can destroy hollow rhodoliths. Rhodoliths and other forms of coralline red algae play a key role in a plurality of environments and need improved management and protection plans. © 2014 Macmillan Publishers Limited.