Modeling of changes in thermal bioclimate: examples based on urban spaces in Freiburg, Germany

The Place of the Old Synagogue is a popular place in the city center of Freiburg, a medium-sized city in southwest Germany. It is going to be redesigned soon. In this paper the impact of urban street design and surface material on human thermal comfort is analyzed using the example of the Place of the Old Synagogue. The models SkyHelios, RayMan, and ENVI-met were applied to quantify and qualify the changes. All three models are freely available. Their combination allows analysis of development in long-term conditions, as well as changes in spatial distribution of thermal comfort, as well as of heat stress in summer. Results show that the models can provide valuable information. About the Place of the Old Synagogue, quantitative results show that the period with heat stress will become longer, while the intensity of heat stress increases. The spatial results show that the most significant changes are due to changes in shading. Nevertheless, an increase in thermal stress up to 10 °C is calculated for areas, where ground coverage changes from grass to pavement.     

Seismic observations at an overstep of the western North Anatolian Fault (Abant–Sapanca region, Turkey)

The course of the active North Anatolian Fault system from Lake Abant to Lake Sapanca was traced by its high micro-earthquake activity. If approaching from the east this section includes a broad south to north overstep (fault offset) of the main fault. Local seismicity has been recorded in this area by a semi-permanent network of 8 stations since 1985 within the frame of the Turkish–German Joint Project for Earthquake Research. The effect of the overstep and its complex fracture kinematics are reflected by the seismicity distribution, the variations of composite fault-plane solutions, and by the spatial coda-Q distribution. Areas of different stress orientation can be distinguished and assigned to different groups of faults. The stresses and the tectonic pattern only in part correspond to a simple model of an extensional overstep and its correlative pull-apart basin. Other types of deformation involved are characterized by normal faulting on faults parallel to the general course of the main strike-slip fault and by synthetic strike-slip faults oriented similar to Riedel shears. Shear deformation by this fault group widely distributed in an area north and east of the main fault line may play an important role in the evolution of the overstep. The development of a pull-apart basin is inhibited along the eastern half of the overstep and compatibility of both strands of the main fault (Bolu–Lake Abant and Lake Sapanca– Izmit–Marmara Sea) seems to be achieved with the aid of the fault systems mentioned. The extension of the missing part of the pull-apart basin seems to be displaced to positions remote from the Lake Abant–Lake Sapanca main fault line, i.e. to the Akyaz?–Düzce basin tract. Highest Q-values (lowest attenuation of seismic waves) were found in the zone of highest seismicity north and west of the overstep which is the zone of strongest horizontal tension. If high coda-Q is an indicator for strong scattering of seismic waves it might be related to extensional opening of fractures.     

Die Bedeutung der Versumpfung für die Entstehung von Hochmooren in Deutschland

Zusammenfassung Es ist nur bei Gebirgsmooren zulässig, von Versumpfungsmooren zu reden. Die als solche erscheinenden Hochmoore des Flachlandes dürften in der Mehrzahl der Fälle keine Versumpfungsmoore im engeren Sinne sein, sondern nur durch Versumpfugserscheinungen in ihrer Ausbreitung geförderte Hochmoore, die ursprünglich als Hochmoore auf eutrophen und mesotrophen Moorschichten begannen (sogen. kombinierte Profile).Das Vorhandensein von Hochmooren des Flachlandes, die wirklich durch Versumpfung ins Leben gerufen worden sind, ist erst noch zu beweisen.     

Heat island and oasis effects of vegetative canopies: Micro-meteorological field-measurements

Dry-bulb temperature, dew-point, wind speed, and wind direction were measured in and around an isolated vegetative canopy in Davis CA from 12 to 25 October 1986. These meteorological variables were measured 1.5 m above ground along a transect of 7 weather stations set up across the canopy and the upwind/downwind open fields. These variables were averaged every 15 minutes for a period of two weeks so we could analyze their diurnal cycles as well as their spatial variability. The results indicate significant nocturnal heat islands and daytime oases within the vegetation stand, especially in clear weather. Inside the canopy within 5 m of its upwind edge, daytime temperature fell by as much as 4.5 °C, whereas the nighttime temperature rose by 1 °C. Deeper into the canopy and downwind, the daytime drop in temperature reached 6 °C, and the nighttime increase reached 2 °C. Wind speed was reduced by ~ 2 ms^–1 in mild conditions and by as much as 6.7 ms^–1 during cyclonic weather when open-field wind speed was in the neighborhood of 8 ms^–1. Data from this project were used to construct correlations between temperature and wind speed within the canopy and their corresponding ambient, open-field values.With 10 Figures     

A review of: “Physical fluid dynamics”

Abstract

by D. J. Tritton, Second Edition, Oxford University Press XVII + 519 pp. Hardback (ISBN 0–19–854489–8) $35.00; paperback (ISBN 0–19–854493–6) $16.95; 1988.     

An exceptional eruption: Mt. Niragongo,Jan. 10th, 1977

The two westernmost volcanoes of the Virunga range (Zaïre Rep.) have just offered simultaneous eruptions. The volcano Niragongo delivered an exeeptionally short, yet important, eruption on 10 Jan. 1977. More than 20 × 10 m³ of molten melilite nephelinite were drained from the 3,270 m suspended lava-lake and spread over 20 km² in less than one hour. This put an end to the half-a-century old sub-permanent lava-lake activity which had rendered Niragongo known world-wide. This event happened during a flank eruption (the new Murara vent) of the close-by sister-volcano, Nyamlagira. This Murara event is quite similar to the many previous ones observed during the last 40 years. Neither of the two outbursts did have, even slightly, any detectable effect on each other. Yet, this simultaneity is probably not due to mere coïncidence.     

Sr-isotope stratigraphy of the Upper Jurassic of central Portugal (Lusitanian Basin) based on oyster shells

Strontium isotope stratigraphy was performed on oyster shells from the Late Jurassic of the Lusitanian Basin (central Portugal). This represents the first approach to obtain numerical ages for these strata. The new chronostratigraphic data provide a more precise age determination of several units. After a basin-wide hiatus sedimentation in the Late Jurassic is proven in the Cabo Mondego and Cabaços formations to resume as early as the Middle Oxfordian. The Alcobaça formation can be placed in the latest Late Oxfordian to Late Kimmeridgian, while data from the upper part of the Abadia Formation indicate an Early to Late Kimmeridgian age. The Farta Pao formation ranges from the latest Kimmeridgian to the latest Tithonian. The largely synchronous Sobral, Arranhó I, and Arranhó II members are overlain by the late Early to Late Tithonian Freixial Member. The brief, local carbonate incursion of the Arranhó I member marks the Kimmeridgian–Tithonian boundary. Oysters are shown once more to be suitable for strontium isotope studies. Their calcitic shells are often unaffected by diagenesis. In particular for marginal marine Jurassic and Cretaceous strata, where belemnites are usually absent, oysters may serve as a valuable tool for isotope stratigraphy.     

Geochemistry and lithofacies of Permo-Carboniferous carbonaceous rocks from the southwestern edge of the Bohemian Massif (Germany). A contribution to facies analysis of continental anoxic environments

The Permo-Carboniferous Schmidgaden, Weiden, Erbendorf and Stockheim basins from southern Germany host discontinuous seams of high ash coal and carbargillites which were mined for hard coal, explored for uranium and only recently have proved their source rock potential for gaseous and fluid hydrocarbons. Alteration and facies of these carbonaceous beds were geologically and chemically investigated. During silicification which is exclusively confined to the carbonaceous interbeds of pyroclastic depositions, element depletion prograded except for Zn, Pb, U. The anoxic environments under consideration may be subdivided into fluvial/swamp (Upper Westphalian beds from Schmidgaden, Weiden, Erbendorf and Stockheim) and lacustrine depositions (Upper Stephanian and Upper Autunian carbargillites from Erbendorf, Weiden-Bechtsrieth). SiO₂, MgO, CaO, Mo and Zr have proved to be most suitable for recognition of these environments, whereas, U, K₂O and notably Cu/Zn are less appropriate. In the ternary plots displaying the organic chemistry of extracts of these carbonaceous beds fluvial swamps have low and lacustrine beds high contents of saturated hydrocarbons. All samples show a pronounced OEP (=odd even predominance) of n-alkanes which partly are environment-controlled (terrestrial origin), partly maturity-controlled. The high iso- and cyclo-alkanes of Schmidgaden and bimodal n-alkyl distribution point to a contribution of algal material. Finally four basin types bearing carbonaceous rocks are discussed with respect to their economic potential and compared with basins elsewhere (Cerilly, Lodève, St. Hippolyte, Uinta): type I: intramontane fault-bounded basin (swamp), type II: volcanic-depression with steep relief (swamps), type III: halfgraben (lake), type IV: volcanic-depression with smooth relief (lake). Types I and II are of interest for hard coal, organic-hosted U-deposits and mainly gasprone; types III and IV, however, show good source-rock potential for crude oil.     

Annealing studies of fission tracks in allanite

The annealing characteristics of fission tracks in allanite have been studied. All the tracks in the mineral fade at 720° C for one hour heating. The activation energy of allanite ranges from 1.4 to 3.4 eV.