The climate of Lower Franconia since 1500

Summary The present article summarizes the essential methods and results of an investigation which was carried out by the paleoclimatological working group of the Geographical Institute of the University of Würzburg from 1983–1989. The aim of this investigation was a seasonal scale reconstruction of the historical climate of Lower Franconia (southern Germany) using instrumental data, narrative sources and harvest records for wine, grain and hay as well as dendrological data (proxy data). Both method and data discussed and regional climate patterns within Franconia are presented.With 2 Figures     

Land reclamation in Singapore,Hong Kong and Macau

The spatial and temporal significance of land reclamation from the sea in relation to the development of the three SE Asian small coastal territories of Singapore, Hong Kong and Macau are examined and compared. In all three territories the rate of reclamation has been an index of the rate of economic development. Four phases of land reclamation are identified: (1) pre-1900: involved relatively unplanned and uncostly projects in shallow water and swamplands around the main focus of settlement; (2) 1900–1945: involved military projects outside the main settlement core; (3) 1945–1980: this phase of large-scale projects unconstrained by natural conditions because of advances in technology and high rate of reclamation was driven by rapid industrial and population growth; (4) 1980 to date: a period marked by large infrastructure projects designed to maintain and extend the status of the territories as world economic and commercial centres. Currently 10%, 5% and 33% of the total land surfaces of Singapore, Hong Kong and Macau respectively comprise land reclaimed from the sea and these proportions will continue to rise.     

Gibbsite solubility and thermodynamic properties of hydroxy-aluminum ions in aqueous solution at 25°C

Solubility curves were determined for a synthetic gibbsite and a natural gibbsite (Minas Gerais, Brazil) from pH 4 to 9, in 0.2% gibbsite suspensions in 0.01 M NaNO₃ that were buffered by low concentrations of non-complexing buffer agents. Equilibrium solubility was approached from oversaturation (in suspensions spiked with Al(NO₃)₃ solution), and also from undersaturation in some synthetic gibbsite suspensions. Mononuclear Al ion concentrations and pH values were periodically determined. Within 1 month or less, data from over-and undersaturated suspensions of synthetic gibbsite converged to describe an equilibrium solubility curve. A downward shift of the solubility curve, beginning at pH 6.7, indicates that a phase more stable than gibbsite controls Al solubility in alkaline systems. Extrapolation of the initial portion of the high-pH side of the synthetic gibbsite solubility curve provides the first unified equilibrium experimental model of Al ion speciation in waters from pH 4 to 9.The significant mononuclear ion species at equilibrium with gibbsite are Al³⁺, AlOH²⁺, Al(OH)⁺₂ and Al(OH)^?₄, and their ion activity products are $\text{1K}{}_{50}\text{= 1.29 × 10}{}^8$, $\text{1K}{}_{\mathrm{s1}}\text{= 1.33 × 10}{}^3$, $\text{1K}{}_{\mathrm{s2}}\text{= 9.49 × 10}{}^{\mathrm{?3}}$ and $\text{1K}{}_{\mathrm{s4}}\text{= 8.94 × 10}{}^{\mathrm{?15}}$. The calculated standard Gibbs free energies of formation (ΔG°_f) for the synthetic gibbsite and the A1OH²⁺, Al(OH)⁺₂ and Al(OH)^?₄ ions are ?276.0, ?166.9, ?216.5 and ?313.5 kcal mol^?1, respectively. These ΔG°_f values are based on the recently revised ΔG°_f value for Al³⁺ (?117.0 ± 0.3 kcal mol_?1) and carry the same uncertainty. The ΔG°_f of the natural gibbsite is ?275.1 ± 0.4 kcal mol^?, which suggests that a range of ΔG°_f values can exist even for relatively simple natural minerals.     

Variations in Reconstructed Ice Winter Severity in the Western Baltic from 1501 to 1995, and their implications for the North Atlantic Oscillation

Variations in ice winter severity in the Western Baltic between 1501 and 1995 were investigated using an index time series derived from classified values of accumulated areal ice volume along the German Baltic coast, the time series back to 1701, having been extended to the beginning of the 16th century. When compared with the 1501–1995 mean, the Gaussian lowpass-filtered time series of the ice winter index numerals with a 40-year cutoff period shows increased severity (strong phases) in 1554–1576, 1593–1630, 1655–1710, and 1763–1860, while periods of decreased severity occurred in 1501–1553, 1577–1592, 1631–1654, 1711–1762, and from 1861 to the present. During the latter part of the Little Ice Age, especially during the 1655–1710 and 1763–1860 phases, the lowpass-filtered time series lay more than half a standard deviation above the arithmetic mean of the reference period 1901–1960, representing the present regime, for more than three decades. Between 1501 and 1860, the ice winter severity in the Western Baltic fluctuated around a level 55% higher than that during the present period. Using the contingency table published by Koslowski and Loewe, the frequency of events of weak westerly flow above the northeastern North Atlantic during the Little Ice Age was estimated. The calculated values of weak westerly flow expected per decade suggest that strong phases of increased ice winter severity were characterized by frequent blocking situations (weak westerly flow), and that, contrarily, the weak phases of reduced ice winter severity between about 1575 and 1860 may be regarded as phases of increased zonal circulation.     

International multidisciplinary ecological research and bioprotection

The following article combines the review of a significant new book concerning the environment issue with a short report on new developments of the UN Environment Programme in general and UNESCO's Man and the Biosphere Programme in particular.     

Regional landslide risk to the Cairns community

A GIS-based regional reconnaissance-level assessment of landslide risk to the Cairns community has been carried out to provide information to the Cairns City Council for planning and emergency management purposes. Magnitude recurrence relations were tentatively established for the two main slope processes: landslides on the hill slopes; and large debris flows extending out from the gully systems on to the plains. From the recurrence relations, landslide hazard (H) was estimated as the annual probability of a point being impacted by a landslide. The nature, number (E) and geographic distribution of the elements at risk were obtained by interrogating the GIS, and their vulnerabilities (V) to destruction by the two main landslide slope processes were assessed. From this information, specific risk (= H × V) and total risk (= H × V× E) maps were produced.Although total landslide risk is relatively low at present, it will increase as development extends further into the hill slopes, unless adequate mitigation measures are taken. Large debris flows, while considerably less frequent than landslides on cut slopes, could impact on subdivisions at the base of the slopes. Blockage by landslides of roads and railways providing access to Cairns can cause isolation of the community. Flash flooding in Freshwater Creek, or debris flows, have the potential to disrupt the Cairns water supply by blocking the intake or destroying sections of the pipeline.     

Ground-Based and Airborne Measurements of Nonmethane Hydrocarbons in BERLIOZ: Analysis and Selected Results

During the Berlin Ozone Experiment BERLIOZ in July–August 1998 quasi-continuous measurements ofC₂–C₁₂ nonmethane hydrocarbons (NMHCs) were carried out at 10 sites in and around the city of Berlin using on-line gas-chromatographic systems (GCs) with a temporal resolution of 20–120 minutes. Additional airborne NMHCmeasurements were made using canister sampling on three aircraft and an on-line GC system on a fourth aircraft. The ground based data are analyzed to characterize the different sites and to identify the influence of emissions from Berlin on its surroundings. Benzene mixing ratios at the 4 rural sites were rather low (<0.5 ppbv). Berlin (and the surrounding highway ring) was identified as the main source of anthropogenic NMHCs at Eichstädt and Blossin, whilst other sources were important at the furthermost site Menz. The median toluene/benzene concentration ratio in Berlin was 2.3 ppbv/ppbv, agreeing well with measurements in other German cities. As expected, the ratios at the background sites decreased with increasing distance to Berlin and were usually around one or below. On 20 and 21 July, the three northwesterly sites were situated downwind of Berlin and thus were influenced by its emissions. Considering the distance between the sites and the windspeed, the city plume was observed at reasonable time scales, showing decreasing toluene/benzene ratios of 2.3, 1.6 and 1.3 with increasing distance from Berlin. Isoprene was the only biogenic NMHC measured at BERLIOZ. It was themost abundant compound at the background sites on the hotter days, dominating the local NMHC reactivity with averaged contributions to the total OH loss rate of 51% and 70% at Pabstthum and Blossin, respectively. Emissionratios (relative to CO and to the sum of analysed NMHCs) were derived from airborne measurements. The comparison with an emission inventory suggests traffic-related emissions to be the predominating source of the considered hydrocarbon species. Problems were identified with the emission inventory for propane, ethene and pentanes.     

Diversity of the Woody Vegetation of Gondwanan Southern Africa

The flora of Gondwanan southern Africa is represented in the rock record by micro-fossils, macro-fossils and petrified woods. All these types of fossils are seldom preserved together in any one particular facies because of taphonomic and preservational biases. In order to obtain as accurate a picture as possible of the woody vegetation, both the fossil woods and other macroplant fossils, such as leaf impressions, fructifications and cuticle, of woody plants, have been correlated. This was done for each Formation in the Karoo Supergroup in order to illustrate the changes in diversity of woody vegetation over time. Sediments of the Karoo Supergroup represent the terrestrial fossil record of the period Upper Carboniferous to the Lower Cretaceous when Africa finally separated from South America. In the Upper Carboniferous to Lower Permian (Dwyka Formation) there are at least five described genera of woods from South Africa and Namibia. Early to Middle Permian woods (Ecca Group) are a little more diverse with six genera, representing the glossopterids, cordaitaleans and possibly other seed fern groups. Late Permian to Early Triassic (Beaufort Group) woods show very little change in diversity in spite of the major floral and biotic turnover evident from the rest of the fossil record. Although the Late Triassic (Molteno Formation) macro-flora has been shown to be an example of explosive diversification, the generally poorly preserved woods do not reflect this. Lower Jurassic fossils (Clarens Formation) are also poorly preserved but have araucarian characteristics. Early Cretaceous woods represent the Araucariaceae, Cheirolepidiaceae and Podocarpaceae with a number of species. The diversity of the woods has not changed as much as the rest of the floral components in southern Africa from the Late Carboniferous to the Early Cretaceous. Possible reasons for this apparent stasis are the conservative nature of wood, functional restrictions, limitations of suitable conditions for petrifications and the fact that very little research has been done on southern African woods.     

Effect of sill spacing and sediment size grading on scouring at grade‐control structures

Sequences of arti?cial steps are sometimes used to reproduce the natural step–pool morphology of high‐gradient streams. The depth, length and shape of the scour holes in gravel‐bed rivers can be predicted reasonably using recently developed formulae. However, the properties of the scour holes can sometimes be affected by the distance between structures. This effect is called ‘geometrical interference’ and leads to a reduction of the scour hole compared to its potential size. Geometrical interference may occur in sequences of arti?cial steps in high‐gradient torrents, where structures are sometimes built at distances of a few tens of metres apart, but may also apply to natural step–pool systems. In this paper, a series of tests have been conducted to determine the effect of bed sill spacing and sediment grading on the potential erosion by jets forming over the sills. A new formula is derived, applicable to high‐gradient streams (slope > 0·04), which can be applied to the special case of scour holes developed by interfering sills. Sediment size gradation, not accounted for in previous formulae, is found to have a signi?cant effect on the scour dimensions and is included in the new predictive formula. Copyright © 2004 John Wiley & Sons, Ltd.     

The Banda Sea earthquake of 24 November 1983: evidence for intermediate depth thrust faulting in the Benioff zone

On 24 November 1983, a major earthquake occurred at 180 km depth beneath the Banda Sea. In the focal mechanism solution the pressure axis is almost horizontal, (azimuth 191°, plunge 02°) and the tension axis nearly vertical (plunge 88°). A comparison with the foreshock-aftershock pattern suggests that shear failure took place within the north-north-westerly dipping Benioff zone by thrust faulting along a southerly dipping plane. The focal mechanism solution does not conform to the usual pattern of the tension or compression axis being roughly parallel to the dip of the Benioff zone. Consequently the faulting could not have been caused by down-dip tension or compression within a sinking slab.