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[Karl Fuchs]: Das Marienbild, genannt das Vesperbild, zu Mergentheim. Sein Alter, seine Geschichte, sein Einfluß auf Mergentheim und dessen Stellung im Tauberthale. Mergentheim 18353.

Knowledge of the present-day crustal in-situ stress field is a key for the understanding of geodynamic processes such as global plate tectonics and earthquakes. It is also essential for the management of geo-reservoirs and underground storage sites for energy and waste. Since 1986, the World Stress Map (WSM) project has systematically compiled the orientation of maximum horizontal stress (S-Hmax). For the 30th anniversary of the project, the WSM database has been updated significantly with 42,870 data records which is double the amount of data in comparison to the database release in 2008. The update focuses on areas with previously sparse data coverage to resolve the stress pattern on different spatial scales. In this paper, we present details of the new WSM database release 2016 and an analysis of global and regional stress pattern. With the higher data density, we can now resolve stress pattern heterogeneities from plate-wide to local scales. In particular, we show two examples of 40 degrees-60 degrees S-Hmax rotations within 70 km. These rotations can be used as proxies to better understand the relative importance of plate boundary forces that control the long wave-length pattern in comparison to regional and local controls of the crustal stress state. In the new WSM project phase IV that started in 2017, we will continue to further refine the information on the S-Hmax orientation and the stress regime. However, we will also focus on the compilation of stress magnitude data as this information is essential for the calibration of geomechanical-numerical models. This enables us to derive a 3-D continuous description of the stress tensor from point-wise and incomplete stress tensor information provided with the WSM database. Such forward models are required for safety aspects of anthropogenic activities in the underground and for a better understanding of tectonic processes such as the earthquake cycle.

Two major earthquakes ‘which shook the world’, that of Lisbon of 1755 and that of Aceh/Sumatra of 2004, are compared. Both were catastrophic earthquakes with nearly identical magnitude M≈9 and accompanying destructive tsunamis. They are paradigms for Low Probability Extreme Events (LPEEs) and for the reaction of the societies in which they occurred, although 250 years apart. Modern seismology developed from its birth as disaster management following the Lisbon quake to a mature science, which however, still remains under the obligation to improve its role in enhancing society's preparedness for such catastrophes. The catastrophe of hurricane Katrina, which was predicted, showed that the realm of societal responsibility extends beyond that of scientific technical competence.

Aims: To develop a protocol for harvesting ex vivo samples of gingival-biofilm consortia and to investigate their basic characteristics. Methods and Results: Gingival epithelial cells with attached biofilm were collected from healthy subjects by taking a smear. The bacterial viability was estimated via the alteration of the membrane permeability and metabolic activity via the double/single-stranded nucleic acid ratio using a confocal laser-scanning microscope. Morphological analysis was performed by scanning and transmission electron microscopy. Additionally, microbiological estimations were made. The electron microscopy revealed fimbriae-mediated adhesion and the formation of a biofilm matrix. Most bacteria were viable and had a high metabolic activity. Conclusions: The presented study offers an easy to follow approach for harvesting samples of gingival-biofilm consortia. The latter differs considerably from the supragingival plaque in viability and zonal distribution. Related to free-living and in vitro-grown biofilms, the gingiva-associated biofilm revealed an atypically high metabolic activity. Significance and Impact of the Study: Biofilm fragments should possess the basic features of the entire gingiva-associated biofilm; which as yet cannot be simulated in vitro. Thus, samples of ex vivo gingival-biofilm consortia can be used to investigate the resistance of oral biofilms against antibiotics and biocides.

Chlorhexidine, the most used biocide in periodontology, alters the permeability of the bacterial cell membrane. However, the chlorhexidine-induced morphological alterations in the oral biofilm have not been studied. To examine the effects of chlorhexidine on oral biofilm on an electron microscopic level, gingival epithelial cells with attached biofilm were collected from 10 volunteers, subjected to 0.1% chlorhexidine for 1 or 5 min, stained with ruthenium red-tetroxide, and analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM visualized the bacterial glycocalyces and the biofilm matrix on the biofilm surface; however, no chlorhexidine-induced alterations were observed. TEM revealed loss of bacterial membrane integrity and fimbrial disintegration in a few bacteria. In the proximity of these alterations, a restricted matrix disintegration was also observed. However, the chlorhexidine-induced alterations only effected a minor part of the oral biofilm and did not cause its disintegration. These findings suggest the insufficient efficiency of chlorhexidine against oral biofilm.

Background: Glycaemic disorders and oral candidosis can be accompanied by burning mouth sensations. However, no clear relation between all three disorders is known. Methods: Seventy-two native Upper-Austrians with burning mouth sensations were examined and smears for Candida estimation were taken from the spots where the sensations were felt. All patients with previously unknown diabetes mellitus (DM) were subjected to an oral glucose tolerance test (OGTT). Use of glucocorticoid-containing anti-asthmatic sprays and the body mass index (BMI) were determined. Results: Of the examined non-inhalers of sprays, 52% had increased candidal density. A correlation between that increase and type 2 DM was found. The burning sensations in all patients with increased candidal density subsided completely after anti-mycotic therapy. Conclusion: The perception of burning sensations was hypothesised to occur via stimulation of the capsaicin (vanilloid) receptor by Candida metabolites. The Candida-induced stomatopyrosis should be regarded as a single symptom indicating (predisposition to or established) type 2 DM in non-inhalers of the concerned population.

The purpose of this study was to investigate, by electron microscopy, the type of bacterial attachment to the sulcular epithelium in periodontitis. Gingiva biopsies were observed in a transmission electron microscope using cytochemical staining with ruthenium red for glycocalyx visualisation. In addition, subgingival plaque samples and biopsies from the sulcular epithelium in periodontitis from the patients were estimated microbiologically. Aerobic bacteria only were estimated in the subgingival plaque and both aerobic and anaerobic bacteria in the gingival biopsies. No bacterial internalisation could be observed. Fimbria-mediated adhesion as the only type of bacterial attachment and a large diversity of bacterial glycocalyces were detected. As the fimbrial adhesins of putative periodontal pathogens are able in vitro to induce inflammation and bone resorption via stimulation of the proinflammatory cytokine production, the demonstrated fimbrial adhesins suggest the significant role of bacterial adhesion to sulcular epithelium in periodontitis.

I have been asked to contribute with some informal personal impressions from the early time in Stephan Mueller’s scientific career at Karlsruhe and before to the opening of this first Stephan Mueller conference. These times between 1959– 1972 are unforgettable because I met a colleague, an advisor and, last not least, a friend. What did we learn from Stephan almost 40 years ago? What should we keep in mind as we try to master the future of Earth Sciences in Europe? Out of many advises Stephan had a simple rule which I want to share with you. It may surprise you, he himself followed it almost 100%, and he transmitted it to his students and colleagues at Karlsruhe in the early sixties: A good presentation has always to start with a seismogram. I will follow this rule now

Modern civilisation explores and penetrates the interior of the Earth's crust, recovers from it and stores into it solids, fluids and gases to a hitherto unprecedented degree. Management of underground structures such as boreholes or reservoirs take into account the existing stress either to take advantage of it or at least to minimise the effects of man-made stress. This paper presents the World Map of Tectonic Stresses (in short: World Stress Map or WSM) as a fundamental geophysical data-base. The impact of the WSM is pointed out: in the context of global tectonics, in seismic hazard quantification and in a wide range of technological problems in industrial applications such as oil reservoir management and stability of underground openings (tunnels, boreholes and waste disposal sites).

Pn phases are observed along many refraction seismic profiles and are common in earthquake records. Their velocities usually range from 7.8 to 8.2 km s−1. Classical ray theory used to interpret these observations implies a positive upper mantle velocity gradient. However, a wide spread positive velocity gradient in the lithospheric mantle is not expected from petrological and petrophysical data. Laboratory velocity measurements at elevated temparatures and pressures suggest positive velocity gradients only for very low heat flow values (≤40 mW m−2). Higher heat flow causes negative gradients. Consequently, petrological models of the upper mantle would restrict Pn observations to Precambrian shields and old platforms, contrary to observations. We overcome this contradiction by considering media that contain random velocity fluctuations superimposed on positive or negative velocity gradients. In both cases, these structures generate Pn phases by wide-angle scattered waves. Short-wavelength random velocity fluctuations of only 0.5–1% superimposed on negative velocity gradients are sufficient for generating Pn phases. Consequently, this implies that an observed Pn wave does not necessitate a positive upper mantle velocity gradient. For a peridotitic upper mantle, fluctuations of this size can be explained by slightly varying the relative proportions of its mineralogical constituents. Anisotropy is likely to contribute to the inferred fluctuations.

High-frequency coda signals consistently recorded by a temporary seismic network of 29 short-period stations during a 6-month survey in the French Massif Central are concordant with independent evidence for a heterogeneous lower crust obtained from wide-angle and near-vertical reflection experiments in the same region. The teleseismic recordings of 22 events have been analysed in record sections rather than as single station seismograms. Following the low-frequency (LF; 0.5–1.5 Hz) first P-arrival a high-frequency (HF) coda (2–4 Hz dominant frequency) extends over several seconds duration. The HF signals become clearly visible after bandpass filtering, but can also be identified in the original seismograms. In event sections the HF coda forms a consistent pattern of reverberations which is characterized by the following properties: (1) the duration is typically longer on the radial (4–15 s) than on the vertical (3–11 s) component; (2) the beginning of the HF coda, referred to the picked LF first P-arrivals varies between 0–2.5 s, with a dominance around 1.5–2 s; (3) the amplitude of the HF coda is about 3%–10% of the primary LF P-phase amplitude; (4) the signals are incoherent between neighbouring stations and over the network; (5) the HF coda arrives dominantly around the plane of incidence of the teleseismic wave in the first 2 s to maximum 4 s; afterwards a widening of the particle motion to an elliptical shape is observed, indicating arrivals off the sagittal plane. The data parameters (1) to (5) point to the conclusion that the HF signals are generated by a scattering process. Wide-angle and CDP-reflection experiments in the same region measured a similar reverberating coda pattern and located the origin also in the lower crust. These observations and the data parameters of the HF coda suggest that the HF teleseismic waves are scattered at heterogeneities in the lower crust in the Massif Central. In this contribution we mainly concentrate on the presentation of the teleseismic recordings and conclude with a preliminary structural model which contains randomly distributed scatterers in the lower crust.

Following two previous experiments in 1985 (KRISP 85) and 1989–1990 (KRISP 90), a series of geophysical experiments was undertaken in 1993–1995 (KRISP 94) to study the lithospheric structure of the southern Kenya rift down to depths of greater than 100 km, with special emphasis on the Chyulu Hills, a complex of volcanic centres on the eastern flank of the rift. KRISP 94 involved a teleseismic tomography experiment of the Chyulu Hills area in July and August 1993, a seismic refraction-wide-angle reflection survey across southern Kenya from Lake Victoria to the Indian Ocean in February 1994, seismicity studies of southern Kenya from 1993 to 1995, a special seismicity study of the Lake Magadi area in February 1994, a gravity study along the seismic-refraction lines before and after the seismic-refraction study, and a magnetotelluric study of southern Kenya in February 1995. Major scientific goals of the project were to reveal the detailed crustal and upper-mantle structure under the southern Kenya rift and its flanks for several 100 km to the west and to the east and their evolution, to study the relationship between deep crustal and uppermost mantle structure, to learn more on the development of sedimentary basins and volcanic features on the flanks and its relation to the Kenya rift, to obtain information on the temperature conditions underneath the rift and its flanks, to perform a particular integrated and calibrative study of seismological and petrological data in the Chyulu Hills, and to understand the processes which are producing extension, uplift, and extensive magmatism. This report is an introduction to a series of subsequent papers. It focuses on the technical description of the main seismic surveys of the KRISP 94 effort and summarizes the key results. During the teleseismic survey an array of 31 seismographs was deployed to record teleseismic, regional and local events for a period of about 3 months from June to August 1993. The elliptical array covered an area about 150 km (N-S) × 100 km (E-W) and spanned the central portion of the Chyulu Hills and its surroundings, with an average station spacing of 10–30 km. The seismic refraction-wide-angle reflection survey was carried out in a 2-week period in February 1994. It consisted of two profiles: one extending from Lake Victoria across the western flank and the southernmost Kenya rift at Lake Magadi, the other extending from Athi River near Nairobi across the eastern flank of the rift, traversing the Chyulu Hills and terminating at the Indian Ocean near Mombasa. A total of 204 mobile seismographs, with an average station interval of about 2 km, recorded the energy of underwater and borehole explosions to distances of up to 730 km. Key results are as follows: (1) The crust reaches a maximum thickness of up to 44 km under the Chyulu Hills. (2) Only a minor upwarping of the crust-mantle boundary is seen under the rift proper in the Lake Magadi area. (3) To the west the crust shallows to about 34 km near Lake Victoria, in contrast to the thickening of the crust further north from the central part of the rift near Lake Baringo towards the west. (4) There is a steep rise of the Moho east of the Chyulu Hills towards the Indian Ocean. (5) P-wave velocities in the uppermost mantle are above 8 km/s except under the rift proper and under the Neogene volcanic centre of the Chyulu Hills, where the velocity is 7.9–8.0 km/s. (6) Under the Chyulu Hills, the Moho is replaced by a gradual crust-mantle transition, and the low velocities near the crust-mantle boundary extend to greater depths as evidenced by teleseismic tomography which indicates a velocity decrease of 3–5%, i.e. from 8.1–8.2 km/s to at least 7.9 km/s. Both effects are probably caused by the local recent volcanic activity, but cannot be interpreted as due to plume activity which is assumed to be present under the Nyanza craton further west. (7) Gravity modelling and first preliminary results of the magnetotelluric measurements support the seismic-refraction and tomographic results. Furthermore, under the western flank the magnetotelluric and gravity data indicate increased conductivity and decreased density in the uppermost mantle below 60–80 km depth.

‘Stress and Stress Release in the Lithosphere’ has been studied within a Collaborative Research Centre at Karlsruhe University (SFB 108) as special contribution from Germany to the International Lithosphere Program (ILP). This synopsis is an outline of the research results obtained by the SFB 108 as presented in this special volume of Tectonophysics . It starts with a summary of ideas on stress and stress release in the lithosphere which guided the SFB 108 at its beginning in 1981. It is followed by a review of strategy in cooperative research on rift systems, world stress map and the scales of structure of the continental lithosphere from crust to mantle. The main observations are then summarized and connections are made between key results from the various disciplines to obtain new views in lithospheric tectonics. Finally we address open questions and perspectives for future research. The research addressed various styles of continental rifting from the Afro-Arabian rift system to the Central European rift system with the Rhinegraben and the grabens in the French Massif Central as outstanding features. A number of critical parameters such as thickness, heat flow, rheology, composition, strength of the crust and of the lithospheric mantle and the influence of active mantle plumes were identified and classified. Together they strongly influence the style of rifting. Petrophysical modelling of integrated information on seismic velocities, composition and temperature from xenolith analysis, density, gravity and topography provided essential constraints on plume-lithosphere interaction in the French Massif Central and also in the Kenya rift. The Rhinegraben and its Variscan environment offered the opportunity to study different concepts of upper and lower crust, including the occurrence of deep crustal earthquakes and the role of an Alpine detachment. A special concern of the SFB 108 was the distribution of dimensions of heterogeneities in the lithosphere and its relation to the scales of their generating processes. The crust-mantle boundary was recognized as a major change in scales of heterogeneities by deep seismic sounding (DSS) methods applied to the lower crust and the lithospheric mantle. The study of the tectonic stress in western Europe revealed that the crust is in frictional equilibrium down to midcrustal levels and is also decoupled from the mantle allowing adjustive motions of blocks and independent subduction in the foreland of the Alps. This decoupling is achieved in a thin and hot lithosphere driven by mid-Atlantic ridge push and Alpine continent-continent collision. It is described in a quantitative dynamic model of crust-mantle decoupling. The SFB 108 has shown that earth scientists have to rediscover the importance of pattern recognition if complex influences are to be recognized.

The data of the European part of the World Stress Map (WSM) are used to study the western European stress province north of the Alps and Pyrenees. The study area is characterised by an almost homogeneous N 145 degrees E orientation of the maximum horizont

Advances in Deep-Seismic Sounding observations of the lithosphere on continents allow to identify various scales of heterogeneities in the crust-mantle transition. In this paper a fresh look is taken at the dynamic properties of seismic waves propagating through this zone ranging from the lower crust well into the lithospheric mantle as observed in near-vertical reflection and wide-angle refraction experiments. The abrupt termination of near-vertical reflections at the Moho and the coincident presence of a strong coda, accompanying the supercritical PMP reflection phase in record sections of continental seismic wide-angle refraction experiments, reveal a new property of the crust-mantle boundary. The Moho forms a sandwiched mix of crust-mantle material between lower crust and topmost mantle in combination with a step in mean velocity, a significant change in scale of the structural dimensions and of velocity variance. This view is strongly supported by the recognition of the subcrustal lithosphere as a high-frequency (5–10 Hz) scattering wave-guide for long-distance propagation of the Pn phase over more than 3000 km, detected during seismic experiments in Russia using Peaceful Nuclear Explosions. Evidence is brought forward that this high-frequency wave-guide is likely to be present also in the Phanerozoic upper mantle of western Europe. It is furthermore hypothesized that the global propagation of teleseismic Sn or corresponding Pn waves observed on continents and oceans combined with the recording of strong PMP-codas for wave paths on continents points to a world-wide change of scale of structure and velocities near the Moho. A change in scale of heterogeneities under almost all physical and chemical conditions indicates possibly a differential horizontal movement or decoupling of crust and upper mantle at the level of the Moho. The global presence of the scattering Pn wave-guide with a preferred horizontal elongation is hypothetically described as a seismic image of processes in the lithospheric mantle. Locations of present-day tectonic activity where horizontal decoupling between crust and mantle are likely to occur (e.g., subduction at continent-continent collision zones, change of tectonic regimes and continental transform faults) are discussed.

In the Eurasian part of the World Stress Map almost the whole region east of the Tornquist-Teisseyre line is terra incognita. The closure of this information gap is of fundamental importance to the understanding of the geodynamics of the Eurasian continent. A detailed analysis of stress-induced wellbore breakouts has been performed over a 4.1-km-long depth interval in the Vorotilov drillhole (VGS). The borehole is located in the central part of the Russian platform, right in the center of the Vorotilov meteorite impact crater 60 km to the NNE of the city of Nizni Novgorod. An ultrasonic borehole televiewer (BHTV) was used to obtain high-resolution acoustical images from the borehole wall. With an interactive system for analyzing BHTV data the azimuth and shape of borehole breakouts occurring in the depth range of 1.3–4.8 km were analyzed. A statistical analysis of the resulting orientation profile of the breakout azimuths yields an overall direction of the maximum horizontal principal stress S H of N 137°E ± 15°. Variations of breakout orientation with depth ranging from a few degrees up to more than 90° are seen on various depth scales. The observed stress direction of N 137°E agrees very well with the average S H orientation of N 145°E in Central Europe. If this measurement is taken as representative for the Russian platform, the stress field in Russia is only slightly rotated in comparison to Central Europe. This can possibly be interpreted as indicative for the stress field to be governed by broad scale tectonic forces, such as a strong contribution from the forces exerted by the collision zone in the Alpine-Himalayan belt and by the Mid-Atlantic ridge.

A new technique for interpretation of 3-D seismic tomographic models in terms of temperature, degree of partial melt and rock composition is presented and tested. We consider both anharmonic and anelastic temperature effects on seismic velocities as well as the effects of mineral reactions, composition and partial melt. It is shown that composition effect is small (less than 1% of velocity) if there are no strongly depleted, Mg-rich harzburgites. We calculate anharmonic temperature derivatives of seismic velocities from compositions of mantle xenoliths. The parameters of a non-linear frequency and temperature-dependent model of attenuation have been taken from published laboratory experiments and calibrated using global Q observations in the upper mantle. For every block of the tomographic model we calculate the absolute temperature and melt fraction required to fit the observed V p perturbation, the average temperature of the tomographic layer being constrained by the observed surface heat flow. With these temperatures we calculate attenuation, density, V p and V s from petrophysical modelling, using the average for 80 mantle xenoliths samples from the French Massif Central. The technique is applied to a recently published 3-D teleseismic P wave tomographic model of the upper mantle beneath the French Massif Central. The observed velocity perturbations are probably caused there by variations in temperature. Temperature does not reach the dry solidus temperature (except for a few tomographic blocks), although it comes close to it at the depth of 60–100 km below volcanic areas. At high subsolidus temperatures the contribution of anelasticity to velocity perturbations is at least as important as the combined effect of anharmonicity and mineral reactions. Our model is consistent with the Pn velocities from refraction seismic studies, Q S estimations from surface waves, observed gravity, geoid, topography and surface heat flow, as well as with the composition and temperatures derived from mantle xenoliths. We suggest that the lithosphere-asthenosphere boundary is uplifted to 50–60 km depth beneath the main volcanic fields. The central and southern part of the Massif Central is underlain by the hot mantle body (plume?) with a potential temperature that is 100–200°C higher than the average potential temperature of the upper mantle.

Short-period, three-component recordings of the seismic wave field of Peaceful Nuclear Explosions (PNEs) on long-range profiles are used to determine the fine structure of the mantle lithosphere. By analyzing the frequency content of the recorded phases and applying different band-pass filters to the data, it is possible to divide the wave field into two distinctly different constituents: low-frequency body waves traveling along Fermat paths (first arrivals) and the high-frequency teleseismic (or long-range) Pn phase traveling with a group velocity of 8.1 km/s and accompanied by a long, incoherent coda. This high-frequency teleseismic Pn phase is observable from about 750 km, where it separates from the faster first arrival, to the maximum recording distance of 3145 km. It is recorded from shots at different locations and appears to be almost unaffected by the major tectonic feature along the profile, the Urals. The frequency spectrum of this Pn phase contains more high-frequency energy (up to 12 Hz) than first arrivals that penetrate deeper into the upper mantle. The teleseismic high-frequency Pn arrival has a remarkable coda, which is incoherent between closely spaced stations. The coda duration is dependent on the component of motion, being shortest on the vertical and longest on the transverse component. We propose a velocity model that is characterized by a zone extending from the crust-mantle boundary to a depth of about 100 km. This zone has randomly distributed, spatially anisotropic velocity fluctuations. We propose that these velocity heterogeneities are “stretched” in the horizontal direction. This zone forms a scattering waveguide that confines the high-frequency teleseismic Pn. There are indications that below this Pn waveguide, either the scale of the velocity fluctuations or the Q factor changes. This is expressed in a separation of the teleseismic Pn phase from the phase diving deeper into the mantle lithosphere.

The Massif Central, the most significant geomorphological unit of the Hercynian belt in France, is characterized by graben structures which are part of the European Cenozoic Rift System (ECRIS) and also by distinct volcanic episodes, the most recent dated at 20 Ma to 4000 years BP. In order to study the lithosphere-asthenosphere system beneath this volcanic area, we performed a teleseismic field experiment. During a six-month period, a joint French-German team operated a network of 79 mobile short-period seismic stations in addition to the 14 permanent stations. Inversion of P-wave traveltime residuals of teleseismic events recorded by this dense array yielded a detailed image of the 3-D velocity structure beneath the Massif Central down to 180 km depth. The upper 60 km of the lithosphere displays strong lateral heterogeneities and shows a remarkable correlation between the volcanic provinces and the negative velocity perturbations. The 3-D model reveals two channels of low velocities, interpreted as the remaining thermal signature of magma ascent following large lithospheric fractures inherited from Hercynian time and reactivated during Oligocene times. The teleseismic inversion model yields no indication of a low-velocity zone in the mantle associated with the graben structures proper. The observation of smaller velocity perturbations and a change in the shape of the velocity pattern in the 60–100 km depth range indicates a smooth transition from the lithosphere to the asthenosphere, thus giving an idea of the lithosphere thickness. A broad volume of low velocities having a diameter of about 200 km from 100 km depth to the bottom of the model is present beneath the Massif Central. This body is likely to be the source responsible for the volcanism. It could be interpreted as the top of a plume-type structure which is now in its cooling phase.

We present the results of a finite-element modelling study of pull-apart basin formation related to left-stepping left lateral strike-slip faults. The modelling quantifies the relationship between fault geometry (i.e., fault overlap and separation) and pull-apart basin formation. Two depocentres (subbasins) separated by a broad zone of relative uplift in between may develop if the strike-slip domain is characterized by fault underlap. For overlapping faults migration of the subbasins is predicted by the models. Deep subbasins in a large area of subsidence which spans the entire inner fault zone may form if fault overlap is about three times the fault separation. The models suggest that a topographic asymmetry within the fault zone may arise due to a different displacement ratio of the strike-slip faults. The modelling results show that this asymmetry in topography becomes more pronounced towards the more active fault. Thus, basin deepening occurs progressively towards the fault characterized by the largest amount of lateral displacement. Moreover, the results indicate that the smaller the fault separation (less than basin length) the less pronounced the topographic asymmetry. The models provide quantitative estimates for the effects of changes in elastic material properties, the magnitude of the compressive far-field stress and the coefficient of friction of the faults on the resulting topography. Comparison of the modelling results with field observations from the Cerro Blanco-El Barranquete (CBB) subbasin located in the Internal Zone of the Betic Cordillera, southeastern Spain support an interpretation in which the interplay of major faults has formed the CBB subbasin.

Stress orientations inferred from breakout directions found in 17 wellbores in the Central Graben area of the North Sea have a bimodal distribution. One orientation of S Hmax trends subparallel to the strike of the Central Graben, while the other is almost perpendicular. The graben itself strikes NW-SE and is subparallel to the orientation of the maximum principal horizontal stress S Hmax of western Europe. The observed stress field was modeled with the help of finite element analysis to explain the bimodal distribution of stress observations and to investigate the degree of refraction of the principal stresses in the vicinity of the graben. The orientation of the principal stresses in the vicinity of a soft sediment graben was determined as a function of the difference in Young's moduli, the far-fieldstress ratio S Hmax /S hmin , and the angle of the far-field stress relative to the strike of the graben axis. The results of the modeling show that contrasts in material properties can modify stress orientations and magnitudes in the vicinity of the graben. Stress orientations near the graben are rotated by up to 90° for substantial variations in Young's modulus and for ratios of the magnitudes of the greatest to least compressive horizontal stress of 1·0–1·5. The FE-modeling results are in good agreement with analytical calculations of stress refraction at the boundary between two elastic media in close contact.

Two major earthquakes ‘which shook the world’, that of Lisbon of 1755 and that of Aceh/Sumatra of 2004, are compared. Both were catastrophic earthquakes with nearly identical magnitude M≈9 and accompanying destructive tsunamis. They are paradigms for Low Probability Extreme Events (LPEEs) and for the reaction of the societies in which they occurred, although 250 years apart. Modern seismology developed from its birth as disaster management following the Lisbon quake to a mature science, which however, still remains under the obligation to improve its role in enhancing society's preparedness for such catastrophes. The catastrophe of hurricane Katrina, which was predicted, showed that the realm of societal responsibility extends beyond that of scientific technical competence.

Although many estimates of crustal stress levels at seismogenic depth have been made on the basis of laboratory data and simple faulting theory, the Kontinentales Tiefbohr (KTB) deep drilling project offers the first opportunity to directly measure at mid-crustal depth the absolute magnitudes of crustal stresses, the uniformity of stress changes with depth, the influence of pore pressure on stress magnitude and the magnitude and orientation of tectonic stresses in the vicinity of the brittle-ductile transition. The planned 10-12 km depth of the KTB Hauptbohrung (main borehole) will penetrate those depths where the shear stresses in the crust are highest and where the greatest discrepancy will exist between observations and predictions if either ‘Byerlee’s law' is not applicable to the mid-crust or near-lithostatic pore pressure exists which substantially weakens the crust.

A review has been undertaken of all available information on crustal stresses in Norwegian continental shelf and North Sea. The data have principally come from the results of borehole breakouts, supplemented by focal mechanisms. A simple model of a soft linear inclusion was developed to explain the rapid changes in stress orientation in the Central Graben area. This example indicates that the stress field is affected locally by the geological or structural environment.

This is an unusual conference. Here we are not mainly speaking to the experts of our own discipline. The common denominator of our presentations and discussions are processes in the solid earth related to temporal and spatial changes in a global scale and their interaction with other processes, possibly of different time scales in the spheres surrounding the lithosphere on which mankind is living. Welcome to this Alfred-Wegener-Conference on the Contribution of Solid Ear th Sciences to the IGBP. Welcome also in the name of the International Lithosphere Program. This conference is held at the request of the Bureau of the InterUnion Commission on the Lithosphere issued at Vancouver, August 1987. The Bureau felt tha t there is an urgent need for a better definition of the role of the solid earth sciences in the new International Geosphere-Biosphere Program, also known as the Global Change Program. To remind y o u t h e ICSU General Assembly in 1986 approved the IGBP-Global Change Program to start in the early 1990's. A special Committee for the IGBP was formed in 1987 comprising 13 members; it is charged with the preparation of the IGBP program at its start in early 1990's. The Special Committee has meanwhile formed 4 Coordinating Panels: 1. Terrestrial Biosphere-Atmospheric Chemistry Interactions (P.J. Crutzen) 2. Marine Biosphere-Atmosphere Interactions (T. Nemoto) 3. Biosphere Aspects of the Hydrological Cycle (S. Dyck) 4. Effects of Climate Change on Terrestrial Ecosystems (B.H. Walker) and 4 working Groups: 1. Global Geopshere-Biosphere Modelling (B. Bollin) 2. Data and Information Systems (S.I. Rasool) 3. Techniques for Extracting En "vtronmental Data of the Past (H. Oeschger); now: Working Group on Global Changes of the Past. 4. Geo-Biosphere Observatories (R. Herrera) One important item in the discussion on the contribution of the solid earth sciences to IGBP is the question of the time scale of global changes to be investigated in IGBP. This discussion is gradually converging

SUMMARY Compared to clear crustal P- and S-waves as well as a strong refracted Pn-wave propagating in the topmost mantle (i.e., 10 to 15 km below the Moho), an anomalously weak appearance of the corresponding refracted shear wave Sn is observed on refraction seismic profiles in SW Germany, France, coastal Maine (NE United States) and Fennoscandia. It is possible that the observation of Pn/PMP ratios close to unity combined with small Sn/SMS ratios (i.e., small Sn amplitudes) is typical for the continental uppermost mantle since this was observed for quite different types of continental crust. It is shown that the observed phenomenon is not a source effect. Several possible causes to explain the observations are studied, also with the aid of synthetic seismograms. The effects of temperature, attentuation and anisotropy have been investigated. Their influence cannot explain the observations. The most likely candidate is a depth-increasing VP/VS ratio (an increase in the order of 0.027 over a depth range of 10 km), forcing P- and S-waves to propagate on different paths in the topmost mantle. The observed phenomenon provides new constraints on the change of composition with depth for the crust mantle transition zone with basalt depletion as the most likely explanation.

Controlled shear-wave sources (a horizontal vibrator and dynamite) were used in near-vertical reflection studies to explore the nature of the reflective laminated lower crust in southwest Germany. The data reveal strong S-wave reflections from the lower crust. These lower crustal S-reflections were not observed by previous wide-angle surveys in the same region. A laminated crustal model with isotropic layers (and changing Poisson's ratio) cannot explain the differing near- and far-offset S-response. By introducing alternating anisotropic and isotropic lamellae, this discrepancy may be resolved. This Seismic model is consistent with a petrological model of deformed amphibolites containing 10–30% of preferentially orientated hornblende. Observed amplitude differences in P- and S-wave reflections from the same depth in the lower crust suggest regions with a changing Poisson's ratio.

Glycaemic disorders and oral candidosis can be accompanied by burning mouth sensations. However, no clear relation between all three disorders is known.Seventy-two native Upper-Austrians with burning mouth sensations were examined and smears for Candida estimation were taken from the spots where the sensations were felt. All patients with previously unknown diabetes mellitus (DM) were subjected to an oral glucose tolerance test (OGTT). Use of glucocorticoid-containing anti-asthmatic sprays and the body mass index (BMI) were determined.Of the examined non-inhalers of sprays, 52% had increased candidal density. A correlation between that increase and type 2 DM was found. The burning sensations in all patients with increased candidal density subsided completely after anti-mycotic therapy.The perception of burning sensations was hypothesised to occur via stimulation of the capsaicin (vanilloid) receptor by Candida metabolites. The Candida-induced stomatopyrosis should be regarded as a single symptom indicating (predisposition to or established) type 2 DM in non-inhalers of the concerned population.

Seismic investigations of the Earth’s velocity structure have revealed a rather complex image of the Earth, exemplified by velocity perturbations of several percent over scales ranging from centimeters to thousands of kilometers (Figure 11.1). Reflection seismic data often show a “layered”, reflective lower crust (Mooney and Meissner, 1992) with velocity inhomogeneities up to 10% (e.g., Sandmeier and Wenzel, 1986; 1990; Levander and Holliger, 1992). The spatial distribution of lower crustal impedance fluctuations seems to obey fractal scaling laws over a scale range of at least 0.1–1 km (Hurich, 1996; Hurich, this volume). At the crust/mantle boundary (Moho) the scale of heterogeneity seems to change rapidly.