ALBERT

Description: Quelle für Wärme, Speicher für klimaschädliche Gase, Lagerstätte für grünen Wasserstoff – der Untergrund bietet viele Möglichkeiten. Ein Gastbeitrag.

Description: During weathering of the deep rocks, many actors act together. This is a property characteristic of the entire “Earth system”. For example, fractures open up, through which water flows that carries carbon and reagants with it from above. New minerals are formed and open up further fractures. Large fractures are also a gateway for microbes from above. They multiply at depths where there is carbon and iron is oxidised. The explorer Alexander von Humboldt stated “Everything is interaction”. Under and on the earth. In our example, soil is created.

Description: Weathering needs fractures in the rock. When two tectonic plates collide, the plates slide against each other. During earthquakes fractures in the rock are created. The microscope reveals tiny cracks running through the rock. These micro-fractures are caused by the movement of the rocks against each other, but also when erosion at the Earth's surface removes the burden of the overlying rock. Fractures are necessary to bring water, reagents, and microbes to depth to weather rocks.

Description: To weather rock, reagents are required. For example, CO2 is found in rainwater as carbonic acid or CO2 is produced by plant roots and by microbes. Through the large fractures carbonic acid and CO2 reach great depth – dissolved in water. Through the fine fractures they reach the interior of the rock. There they dissolve minerals, like the feldspar. New, completely different minerals form, for example clay minerals. They create fine fractures through which water with carbon can penetrate further and the weathering begins again.

Description: Weathering of rock needs water. A rock fractured by tectonic movement is gradually eroded from above, and it moves closer towards the Earth's surface. There it is exposed to precipitation and water begins to penetrate the soil and the layers beneath the soil. Through the tectonic fractures, the water can reach great depths. This is a rapid transport process. At a millimetre scale the water slowly moves into the interior along the smallest cracks that occur there. This is a slow transport process. The water can now weather rocks from the inside.

Description: Living organisms can also weather rocks. There are microorganisms in deep rock – in the "deep biosphere". With flowing water, the microbes are transported from soil through the fractures to depth. Down there, in complete darkness, the microbes live on water, carbon, and energy. They can oxidise iron in minerals and receive energy in the process. The iron-containing minerals are oxidised, carbon is consumed, and more and more microbes are created. This is how the deep biosphere keeps itself alive and weathers the rock at the same time.

Description: In a small, forested catchment underlain by gneiss (Conventwald, Black Forest, Germany), we found that the magnesium isotope composition (δ26Mg) of creek water did not show seasonal variability, despite variations in dissolved Mg concentrations. To investigate the potential controlling factors on water δ26Mg values, we studied the Mg isotope composition of solid samples (bedrock, bulk soil, clay-sized fraction of soil, separated minerals, the exchangeable fraction of regolith) and water samples comprising time series of creek water, groundwater and subsurface flow. Subsurface flow from 0–15 cm depth (−0.80 ± 0.08‰) and 15–150 cm depth (−0.66 ± 0.17‰), groundwater (−0.55 ± 0.03‰), and creek water (−0.54 ± 0.04‰) are all depleted in heavy Mg isotopes compared to bedrock (−0.21 ± 0.05‰). Subsurface flow samples have similar δ26Mg values to the regolith exchangeable fraction at the respective sampling depths. Also, groundwater and creek water show δ26Mg values that are identical to those of the exchangeable fraction in the deep regolith. We suggest, therefore, that cation-exchange processes in the regolith control Mg concentrations and δ26Mg values of creek water at our study site. This assumption was further verified by batch adsorption-desorption experiments using soil samples from this study, which showed negligible Mg isotope fractionation during adsorption-desorption. We propose that the exchangeable fraction of the regolith buffers dissolved Mg concentrations by adsorbing and storing Mg when soil solutions are high in concentration in the dry season and desorbing Mg when rainfall infiltrates and percolates through the regolith in the wet season. This mechanism may explain the near chemostatic behavior of Mg concentrations and the invariance of δ26Mg values in creek water. In addition, the depth distribution of exchangeable Mg concentration and isotope composition in the regolith reflects mineral dissolution and secondary mineral formation in deep regolith (〉3 m) and biological cycling in shallower depth (0–3 m). Magnesium stable isotopes thus provide an accurate snapshot of the geogenic (weathering) and the organic (bio-cycled) nutrient cycle.

Description: Se descubre un misterioso crimen en un almacén. Muchas rocas han sido asesinadas. El detective Hércule Poirot emprende la investigación del caso. Para ello, contrata a un grupo de geo-científicos internacionales que buscan a los "culpables" en una campaña de perforación en los espectaculares paisajes de Chile. Los científicos encuentran pruebas del crimen en laboratorios de investigación y presentan una sorprendente solución al caso de asesinato. Esta película aborda una pregunta científica: ¿Cómo se convierte la roca en suelo en las profundidades de la superficie terrestre? Los cuatro "sospechosos" (es decir, los procesos) son las fracturas en la roca, el flujo de agua, los reactivos químicos y los microbios, los cuales se ven en acción en animaciones. Sin embargo, estas hipótesis no pueden demostrarse directamente, sólo puede demostrarse que son falsas, como una coartada en un caso criminal. Vea la película para averiguar si los investigadores logran resolver el caso. Esta película se produjo en el marco del proyecto germano-chileno "EarthShape – Earth iSurface Shaping by Biota". Puede ver de qué se trata aquí: La piel de la Tierra - donde la vida se encuentra con las rocas

Description: In einer Lagerhalle wird ein unglaublicher Mordfall entdeckt. Viele Steine sind ermordet worden! Detektiv Hercule Poirot nimmt die Ermittlungen auf. Er engagiert eine Gruppe internationaler Geo-ForscherInnen für die Suche nach den „Tätern“ in einer Bohrkampagne in spektakulären Landschaften Chiles. Sie finden Nachweise zum Tatvorgang in Forschungslaboratorien – und eine überraschende Auflösung des Mordfalles. Im Film geht es um eine wissenschaftliche Frage: Wie wird durch Verwitterung tief unter der Erdoberfläche Gestein zu Boden? Die vier „Verdächtigen“ (also Prozesse) – Brüche im Gestein, Wasserfluss, chemische Reagenzien und Mikroben werden in Animationen sichtbar. Sie sind jedoch Hypothesen. Diese lassen sich nicht direkt beweisen, sondern nur als falsch nachweisen. Wie ein Alibi in einem Kriminalfall. Schaut den Film, um zu sehen, ob dies gelingt!