Refine
Document Type
- Article (2)
- Monograph/Edited Volume (1)
- Other (1)
Is part of the Bibliography
- yes (4)
Keywords
- Earthquake source observations (1)
- Fracture and flow (1)
- Frauenliteratur (1)
- Geomechanics (1)
- Induced seismicity (1)
- Seismicity and tectonics (1)
- Triggered seismicity (1)
- soziale Bewegung (1)
Institute
Brüche und Umbrüche
(2010)
Einen Überblick über historische Veränderungen der Bedingungen, unter denen Frauen geschrieben haben, sollte eine Ringvorlesung vermitteln, die das Institut für Germanistik der Universität Potsdam in zwei Semestern der Jahre 2005/06 veranstaltete. Unter dem Titel »Lesen und Schreiben in Umbrüchen« macht der Lehrplan in Brandenburg und Berlin für die Sekundarstufe II mindestens zwei der drei Umbrüche von 1933, 1945 und 1989 verbindlich zum Gegenstand des Literaturunterrichts. Als Institut der einzigen lehrerbildenden Universität des Landes wollten wir nicht nur Vorschläge machen, welche Autoren sich zur Behandlung dieser Umbrüche des zwanzigsten Jahrhunderts anbieten, sondern zum einen durch die Beschränkung auf weibliche Autoren in den Umbrüchen, der Veränderung gesellschaftlichen Verhältnisse, die Geschlechterverhältnisse hervorheben und über ihnen die Brüche in den Biographien nicht aussparen, zum anderen dem Blick auf die Umbrüche zwischen 1933 und 1989 durch eine Einbeziehung früherer Umbrüche historische Tiefenschärfe geben. Von der Französischen Revolution bis zur ›Wende‹ haben gesellschaftliche Umbrüche nicht nur das Leben weiblicher Autoren im Allgemeinen bestimmt, sondern auch ihr Schreiben als eine Auseinandersetzung mit ganz individuellen Brüchen.
Geophysical datasets sensitive to different physical parameters can be used to improve resolution of Earth's internal structure. Herein, we jointly invert long-period magnetotelluric (MT) data and surface-wave dispersion curves. Our approach is based on a joint inversion using a genetic algorithm for a one-dimensional (1-D) isotropic structure, which we extend to 1-D anisotropic media. We apply our new anisotropic joint inversion to datasets from Central Germany demonstrating the capacity of our joint inversion algorithm to establish a 1-D anisotropic model that fits MT and seismic datasets simultaneously and providing new information regarding the deep structure in Central Germany. The lithosphere/asthenosphere boundary is found at approx. 84 km depth and two main anisotropic layers with coincident most conductive/seismic fast-axis direction are resolved at lower crustal and asthenospheric depths. We also quantify the amount of seismic and electrical anisotropy in the asthenosphere showing an emerging agreement between the two anisotropic coefficients.
Seismicity induced by coal mining in the Ruhr region, Germany, has been monitored continuously over the last 25 yr. In 2006, a dense temporary network (HAMNET) was deployed to locally monitor seismicity induced by longwall mining close to the town of Hamm. Between 2006 July and 2007 July, more than 7000 events with magnitudes M-L from -1.7 to 2.0 were detected. The spatiotemporal distribution of seismicity shows high correlation with the mining activity. In order to monitor rupture processes, we set up an automated source inversion routine and successfully perform double couple and full moment tensor (MT) inversions for more than 1000 events with magnitudes above M-L -0.5. The source inversion is based on a full waveform approach, both in the frequency and in the time domain, providing information about the centroid location, focal mechanism, scalar moment and full MT. Inversion results indicate a strong dominance of normal faulting focal mechanisms, with a steeper plane and a subhorizontal one. Fault planes are oriented parallel to the mining stopes. We classify the focal mechanisms based on their orientation and observe different frequency-magnitude distributions for families of events with different focal mechanisms; the overall frequency-magnitude distribution is not fitting the Gutenberg-Richter relation. Full MTs indicate that non-negligible opening tensile components accompanied normal faulting source mechanisms. Finally, extended source models are investigated for largest events. Results suggest that the rupture processes mostly occurred along the subvertical planes.
Various techniques are utilized by the seismological community, extractive industries, energy and geoengineering companies to identify earthquake nucleation processes in close proximity to engineering operation points. These operations may comprise fluid extraction or injections, artificial water reservoir impoundments, open pit and deep mining, deep geothermal power generations or carbon sequestration. In this letter to the editor, we outline several lines of investigation that we suggest to follow to address the discrimination problem between natural seismicity and seismic events induced or triggered by geoengineering activities. These suggestions have been developed by a group of experts during several meetings and workshops, and we feel that their publication as a summary report is helpful for the geoscientific community. Specific investigation procedures and discrimination approaches, on which our recommendations are based, are also published in this Special Issue (SI) of Journal of Seismology.