ALBERT

Beschreibung: Five years after the Earth Summit in Rio de Janeiro, the hesitancy of developed countries is turning out to be the main impediment to implementing an effective policy for sustainable development. Alongside the further development of international environmental regimes, setting up national action plans is necessary to close the action-gap in the North. However, this can only succeed if the action plans include binding objectives that can be monitored and evaluated. Current national strategies for sustainable development only meet this criterion in exceptional cases; in most cases only qualitatively and legally nonbinding objectives are included. In the present paper, a suggestion for a cluster of environmental policy targets is put forth, which - using Germany as an example - establishes the sustainability concept at the national level. Particular emphasis is placed on the normative dimension of target setting.

Beschreibung: The issue or concept of "sustainable development" entered onto the public and political agenda only relatively recently, and, five years after signing Agenda 21, perceptions of it are still ambiguous. A review of organisational adjustments and of German communications to the United Nations Commission on Sustainable Development shows that the German government's level of commitment to Agenda 21 is still low. This view is supported by an assessment of developments, and the Government's poor performance so far, in three institutional indicators. However, there is evidence that some incremental steps towards a sustainability transition are being taken as in some areas of business and industry and local government attitudes are begining to change. In addition, awareness of sustainable development is being raised by the efforts of non‐governmental organisations and the scientific community. Generally though, the lack of institutional reorganisation is the major obstacle to a German sustainability transition. This is an expression of the generally low priority of environmental and global development issues in the aftermath of German unification and the related economic and social problems. The traditional economic paradigm where economic growth is believed to be the precondition for welfare prevails and is considered by a majority of decision‐makers not to be compatible with the sustainability transition.

Beschreibung: This paper takes a look at the development of freight transport and its further perspectives in the light of environmental sustainability. It clearly challenges the traditional view that further growth in freight transport is indispensable whatever stage of economic development an individual economy has achieved. Moreover it suggests measures to be taken into consideration in sectors other than the transport sector which may help to break the trend of continuing freight transport growth. Current developments of freight transport volume and modal split are rather counterproductive as regards curbing the unwanted environmental impacts. As growth in volume is a major contributing factor for most adverse effects caused, a substantial decoupling of economic growth and freight transport would be extremely helpful. While freight transport activity is almost entirely derived demand there can be no sufficient solution for the resulting environmental problems within the sector itself. Therefore, it is necessary to examine potentials for reducing demand for freight transport in all sectors of the economy. Contrasting to the widely held view that freight transport is in general an inevitable prerequisite of economic development, there are potentials for reducing the freight intensity of the economy which could be far more exploited. Such potentials are increasing the share of regional production, slowing down the metabolism of materials in the economy, and substituting transfer of information for transport of physical products. While each of these potentials on its own may appear to offer limited effects, a proper combination might yield substantial results. The presented preliminary ideas suggest that the notion of everlasting freight transport growth is misleading and hint at the necessity for further research.

Beschreibung: A local, broadband, seismic network of four observatory-quality stations (KTB-NET) was operated during the drilling of the KTB hole, within the framework of the interdisciplinary German Continental Deep Drilling Program (KTB). The aim was to investigate the seismic activity with regard to the tectonic stress field and to compare it with data from in situ measurements in the 9.1-km deep borehole sections (bottom temperature of 260°C and heat flow of 82–85 mW/m2). From October 1990 to November 1995, over 80 local microearthquakes with magnitudes from 0.2 to 2.8 ML were recorded: eight small events by the KTB-NET only and four earthquake swarms with 73 events by the KTB-NET and stations of the Vogtland/Western Bohemia networks. Six of the small events are located within or close to the KTB-NET. The swarm events occurred at the southwestern extension of the Ohre rift, in an area 20 km north of the drill site, which is revealed to be part of the Vogtland/Western Bohemia seismotectonic unit, characterized by swarm activity. The hypocenters are limited to the upper 13 km of the crust, with a distinct concentration between 10 and 12 km. All types of fault plane solutions are found, but at depths greater than 8 km, reversed faulting mechanisms predominate. P axes are very uniformly oriented in a NNW-SSE direction, corresponding to the well-known regional stress orientation in central Europe and in agreement with the special in situ stress measurements of the KTB program. The focal mechanism of a ML=1.2 event induced by a fluid injection experiment fits into the results obtained from the natural events. Possible indications for the brittle-ductile transition are discussed in view of the observed earthquake depth and focal mechanism distributions.

Beschreibung: For almost 10 years the KTB superdeep drilling project has offered an excellent field laboratory for adapting seismic techniques to crystalline environments and for testing new ideas for interpreting seismic reflections in terms of lithological or textural properties of metamorphic rock units. The seismic investigations culminated in a three-dimensional (3-D) reflection survey on a 19 × 19 km area with the drill site at its center. Interpretation of these data resulted in a detailed, structural model of the German Continental Deep Drilling Program (KTB) location with dominant, steep faults in the upper crust. The 3-D reflection survey was part of a suite of seismic experiments, ranging from wide-angle reflection and refraction profiles to standard vertical seismic profiles (VSP) and more sophisticated surface-to-borehole observations. It was predicted that the drill bit would meet the most prominent, steeply dipping, crustal reflector at a depth of about 6500–7000 m, and indeed, the borehole penetrated a major fault zone in the depth interval between 6850 and 7300 m. This reflector offered the rare opportunity to relate logging results, reflective properties, and geology to observed and modeled data. Post-Variscan thrusting caused cataclastic deformation, with partial, strong alterations within a steeply dipping reverse fault zone. This process generated impedance contrasts within the fault zone on a lateral scale large enough to cause seismic reflections. This was confirmed by borehole measurements along the whole 9.1 km deep KTB profile. The strongest, reflected signals originated from fluid-filled fractures and cataclastic fracture zones rather than from lithological boundaries (i.e., first-order discontinuities between different rock types) or from texture- and/or foliation-induced anisotropy. During the interpretation of seismic data at KTB several lessons were learned: Conventional processing of two-dimensional (2-D) reflection data from a presite survey showed predominantly subhorizontal layering in the upper crust with reflectivity striking in the Variscan direction. Drilling, however, revealed that all rock units are steeply dipping. This confirms that surface common depth point (CDP) seismics strongly enhances subhorizontal reflectivity and may thus produce a very misleading crustal image. Although this was shown for synthetic examples earlier, the KTB provides the experimental proof of how crucial this insight can be.

Beschreibung: The PUNA (Plateau Untersuchung Nw Argentinien) seismograph network was deployed across the Andes at ∼23.5°S. The array was centered in the backarc, atop the Puna high plateau in NW Argentina and was in operation for approximately 100 days between late August and late November 1997. Most stations were equipped with short-period1-Hz 3-component seismometers and PDAS data loggers recording continuously 100 sps. The deployment was part of the collaborative research center „Deformation processes in the Andes - SFB267”. Waveform data are available from the GEOFON data centre, under network code ZB under CC-BY 4.0 license.

Beschreibung: Fluctuations in the length of day (Δlod) can be caused by temporal variations of the inertia tensor described by the excitation function and by disturbances of the torque balance between core and mantle. Recent models of the atmospheric excitation of the variations of the lod certainly failed with respect to longer periods (e.g., at about 70 years), but seem to be responsible for the annual period, the 22 years period and for a part of the nearly 30 years period. So, another geophysical phenomenon is needed which is responsible for the remaining part of unexplained lod variations. Previous studies of the geomagnetic core-mantle coupling were re-examined using lod values from which atmospherically excited parts were removed. The remaining part of the 30 years period could be explained by core-mantle coupling. Additionally, the torque blance was realized by assuming lower values of the electrical conductivity at the bottom of the mantle. It was concluded that the consideration of geophysical processes within atmosphere and hydrosphere will be important for future refinements of the core-mantle coupling models of the decade fluctuations in the lod.

Beschreibung: The amplitude spectra of global geophysical phenomena were investigated to motivate research of physical connections between them. The suggested causality was derived from comparison of the spectra, and from cross correlation functions. The following global parameters were discussed: for the earth rotation by the variations of the length of day, for the gemagnetic variation by the global field intensity, changes of the dipole axis and the westward drift, and for climate change by the atmospheric excitation function derived from air pressure variations, and temperature variations. The model of atmospheric excitation, which can be proved most exactly for the annual variation of length of day, is responsible for the 11 and 22 years periods, too. It failed for longer periods e. g., partially for the 30 years periods and completely for the 60 to 80 years periods, which were also discovered in the mean temperature and geomagnetic field variations. Therefore, it was suggested that longer periods in climate change and in the variations of the earth's rotation are caused independently by the same process in the earth core, provided that a physical influence of the geomagnetic field on climate will be accepted in future. The investigation was completed by comparison with the spectra of some local temperature variations in Europe.

Beschreibung: The tremor wave‐field at Mt.Etna was recorded with an array of three 3‐component broadband seismometers. The analysis of its polarisation and dispersion properties leads to the conclusions that (1) the wave‐field consists mainly of surface waves and that (2) two of the observed spectral peaks are caused by a wave guide effect along the propagation path.

Beschreibung: The wave-field of volcano-induced seismic signals at Stromboli volcano (Italy) was observed using a network of four broadband seismometers. In addition to the standard spectral analysis of the recorded signals, new spectral techniques such as wavelet transform and wavelet coherence analysis were also used in order to discriminate between signals related to volcanic tremor and volcanic explosions. The common features of these two types of signals are characterised by the maximum of the power spectral density values located in the frequency band > 2.0 Hz, and the main orientation of the principal axes of the particle motion ellipsoids in the frequency bands analysed. The seismic signals of the volcanic explosions at Stromboli cover the total frequency band, whereas the spectral content of the volcanic tremor is restricted to narrow frequency bands ranging from 0.3–5.0 Hz. In order to localize both types of signals, a modified inversion technique was used. The result of this beam-forming on diffraction hyperboloids of both types of signals reveal a surprisingly shallow source location ranging from 0.2 km–0.7 km above sea level, suggesting that the sources of the volcanic explosions, as well as of the volcanic tremor, are restricted to the uppermost parts of the volcano. This is in agreement with several nonseismological observations of this volcano. The combination of spectral analysis of volcanic tremor and volcanic explosions with the analysis of ground displacement implies a mechanism which can be described by an ascending bubble of volcanic gas in a nearly closed volcanic system, and finally the forced ejection of the material through a narrow channel at the top of the magma column.

Beschreibung: A fluid injection-induced seismicity experiment was conducted in the German Continental Deep Drilling Program (KTB) main borehole at 9.1 km depth (in situ temperature of 260°C) to extend knowledge about stress magnitudes and brittle faulting to depths and temperatures approaching the brittle-ductile transition. Almost 400 microearthquakes were induced at an average depth of 8.8 km by injection of KBr/KCl brine into a ∼70 m open hole section near the bottom of the borehole. Although most focal plane mechanisms were poorly constrained due to the very small size of the induced earthquakes, several different clusters of microearthquakes with distinct mechanisms were defined. Most of the microearthquakes for which focal plane mechanisms were determined were strike-slip events with a NNW trending P axis, essentially parallel to the direction of maximum horizontal compression observed in the borehole. The largest induced earthquake, M 1.2, occurred 18 hours after injection was started. This event was a strike-slip/reverse faulting event which also had a NNW trending P axis. Utilization of a precise relative location technique indicates that many of microearthquakes occurred relatively far (50–100 m) from the well bore. Modeling of the pore pressure disturbance caused by injection suggests that many of the earthquakes were induced by extremely small pore pressure perturbations (〈1 MPa) less than 1% greater than the ambient, approximately hydrostatic pore pressure at depth. Thus it is apparent that there are critically stressed, permeable fault zones in the crust, even at great depth and temperature. A frictional analysis of the focal plane mechanisms of the induced microearthquakes indicates that fault slip is consistent with the stress magnitudes and orientations determined in situ at depths to 7.7 km in the borehole and relatively high coefficients of friction (∼0.6–0.7) reported by Brudy et al. [this issue]. This and the observation that very small pore pressure perturbations were able to trigger seismicity appear to confirm the hypothesis that “Byerlee's law” (i.e., that differential stresses in situ are limited by the frictional strength of well-oriented, preexisting faults) is valid to great crustal depth and that the crust is in brittle failure equilibrium at depths and temperatures approaching the brittle-ductile transition, even in this relatively stable intraplate area.

Beschreibung: Rischmüller, H.: Technical Limits for Scientific Drilling and Downhole Measurements. p. 5-15. Storms, M. A.: Science/Industry Cooperation in the Research & Development of ODP Drilling/Coring Technology. p. 19-48. Khakhaev, B. N.: Technological Problems while Drilling Superdeep Wells. p. 51-66. Basovitch, V. S.: Requirements for Borehole Verticality in Superdeep Drilling. p. 69-73. Saito, S.: High Temperature Experiences and Developments in Geothermal Drilling in Kakkonda, Japan. p. 77-95. Guangzhi, Liu: The Strategy and Concept of the Proposed Pilot hole Drilling in China. p. 99-118. Beswick, A. J.: High Quality Coring for Scientific Purpose on Hard Rock to 2000 m. p. 121-123. Beswick, A. J.: Summary of Deep Slimhole Wireline Drilling in South Africa. p. 127-130. Holtrop, J. F.: Some Remarks to Mud Technology and Wellbore Stability. p. 133-134. Rowley, J. C.: Drilling and Coring Technologies for CSD Products. p. 137-148. Gloth, H.: Scientific Drilling, Sampling and Testing up to 5000 m Depth. p. 151-173. Jürgens, R.: Slim Hole and Horizontal Drilling. p. 177-184. Young, F., Hohoff, H., Kerk, T.: UTB: Rig Layout and Rig Operation for Ultradeep Scientific Drilling. p. 187-203. Boyeldieu, C.: Logging while Drilling and other New Logging Technologies. - Their Potential for Lithosphere Research. p. 209-237. Kehrer, P., Bram, K., Draxler, J. K., Kück, J., Kessels, W., Zoth, G.: Subsurface Data Acquisition for Science by Downhole Measurements. p. 241-250. Lysne, P.: Evolution of Downhole Measurement Systems. p. 253-260. Draxler, J. K., Bram, K.: Measurement Systems for in situ Data Acquisition in Normal, Superdeep, Slim and Tough Boreholes. p. 263-277.

Beschreibung: Umsonst, Th., Lauterjung, J., Tran Viet, T., Wöhrl, Th.: Technical aspects and sampling procedures at the KTB-Hauptbohrung. p. A1-A11. Duyster, J., Grawinkel, A., Kontny, A.: Petrographic and Structural Characterization. p. B1-B80. Machon, L.: Geochemistry/Fluid Analysis. p. C1-C28. Rauen, A., Winter, H.: Petrophysical Properties. p. D1-D45. Röckel, Th., Natau, O.: Rock Mechanics. p. E1-E9. Conze, R.: Electronic Data Processing at KTB. p. F1-F13.

Beschreibung: This technical report has been initiated, compiled and edited until March 1994. Its objective was to collect the existing geoscientific database and state of the art on the Uralides. It serves as a platform for financial and operational decisions by national and international funding agencies on the URSEIS95-project (Urals Reflection Seismic Experiment and Integrated Studies) under the EUROPROBE umbrella. The German DEKORP2000 (GFZ Potsdam), funded by BMBF, decided to operate this project in June 1994. Until November 1994, the COCORP project (Cornell University, U.S.A), funded by NSF, and CICYT (Barcelona, Spain) got funding to join a western consortium on the operation ofURSEIS in 1995. Until the end of 1994, a Russian consortium, funded by ROSGEOLCOM, was built under the leadership of SPETSGEOFISIKA (Moscow), integrating the BAZHENOV Geophysical Expedition (Sheelite, Ekaterinburg), BASHNEFTEGEOFISIKA (Ufa) and the GEON institute (Moscow). All partners in the project join forces in financing, acquisition, processing, interpretation and publishing the results of the seismic experiment. The field parameters of the experiment (chapter VI) have been slightly modified in the meantime and include the Vibroseis source technique. The field campaign is scheduled for May-September 1995. The interdisciplinary studies (chapter Vll) have been approved by the E.C. in the frame of the INTAS-programme (International Association for the Promotion of Cooperation with Scientists from the Independent States of the Former Soviet Union). in October 1994 and started their operational phase.

Beschreibung: For many years, in situ stress in the brittle crust has been measured at relatively shallow depth and related to the mechanical behavior of the crust as inferred from laboratory studies and faulting theory. A continuous profile of the magnitudes and orientations of the three principal stresses has been estimated to depths of 7.7 km and 8.6 km in the German Continental Deep Drilling Program (KTB). This was achieved by hydraulic fracturing tests at relatively shallow depth (1–3 km), estimates of the magnitude of the least horizontal principal stress provided by modified hydraulic fracturing experiments at 6 km and 9 km depths, and analysis of compressional (breakouts) and tensile (drilling-induced tensile wall fractures) failures of the borehole wall over nearly the entire depth of the KTB borehole. The orientation of the maximum horizontal principal stress was found to be uniform with depth with an orientation of N160°±10°E, which is consistent with the average orientation found throughout western Europe. The only significant change in stress orientation was observed directly below a major fault zone crosscutting the borehole. The profile of stress magnitudes we have obtained demonstrates that to a depth of 8 km, the state of stress in the brittle crust in southern Germany is in frictional equilibrium. That is, the ratio of shear to normal stress as resolved on preexisting faults which are well-oriented to the in situ stress field is comparable to their frictional strength based on predictions of Coulomb faulting theory for a coefficient of friction of about 0.7 and near-hydrostatic pore pressure.