Classification of coral reef types in Torres Strait (GIS files in zip-archive 319 kB)

Coral reefs represent major accumulations of calcium carbonate (CaCO3). The particularly labyrinthine network of reefs in Torres Strait, north of the Great Barrier Reef (GBR), has been examined in order to estimate their gross CaCO3 productivity. The approach involved a two-step procedure, first characterising and classifying the morphology of reefs based on a classification scheme widely employed on the GBR and then estimating gross CaCO3 productivity rates across the region using a regional census-based approach. This was undertaken by independently verifying published rates of coral reef community gross production for use in Torres Strait, based on site-specific ecological and morphological data. A total of 606 reef platforms were mapped and classified using classification trees. Despite the complexity of the maze of reefs in Torres Strait, there are broad morphological similarities with reefs in the GBR. The spatial distribution and dimensions of reef types across both regions are underpinned by similar geological processes, sea-level history in the Holocene and exposure to the same wind/wave energetic regime, resulting in comparable geomorphic zonation. However, the presence of strong tidal currents flowing through Torres Strait and the relatively shallow and narrow dimensions of the shelf exert a control on local morphology and spatial distribution of the reef platforms. A total amount of 8.7 million tonnes of CaCO3 per year, at an average rate of 3.7 kg CaCO3 m-2 yr-1 (G), were estimated for the studied area. Extrapolated production rates based on detailed and regional census-based approaches for geomorphic zones across Torres Strait were comparable to those reported elsewhere, particularly values for the GBR based on alkalinity-reduction methods. However, differences in mapping methodologies and the impact of reduced calcification due to global trends in coral reef ecological decline and changing oceanic physical conditions warrant further research. The novel method proposed in this study to characterise the geomorphology of reef types based on classification trees provides an objective and repeatable data-driven approach that combined with regional census-based approaches has the potential to be adapted and transferred to different coral reef regions, depicting a more accurate picture of interactions between reef ecology and geomorphology.

Map of Lewis-Glacier - Mt. Kenya 1983 (pdf 600 kB)

In February of 1983 a new terrestrial photogrammetric survey of Lewis Glacier (0° 9' S) has been made, from which the present topographic map has been produced in a scale of 1:5000. Simultaneously a survey of 1963 was evaluated giving a basis for computations of area and volume changes over the 20 year period: Lewis Glacier has lost 22 % of its area and 50 % of its volume. Based on maps and field observations of moraines 10 different stages were identified. Changes of area and volume can be determined for the periods after 1890, two older, undated stages are presumed to be of Little Ice Age-origin. Moderate losses from 1890 to 1920 were followed by strong, uninterrupted retreat up to present. In this respect Lewis Glacier behaves as all other equatorial glaciers that were closer examined. Compared to alpine glaciers the development was similar up to 1950. In the following years, however, the glaciers of the Alps gained mass and advanced while Lewis Glacier experienced its strongest losses from 1974 to 1983.

Tab. 1: Meerfelder Maar Drilling B4, stratigraphy and sequence of the lake sediments (pdf 215 kB)

A core from Meerfelder Maar, with a basal age of 29,000 years, provides a continuous sedimentary sequence from Late-Glacial times to the present. It includes the stratigraphical marker of the Laach Pumice Tuff. Sedimentological, geochemical, palynological, palaeobiological, palaeomagnetic and palaeontological analyses permit reconstructions of the history of the lake and its catchment area, and hence of the climate of the region, to be made. The discovery of Middle Oligocene marine, detrital fossils in the maar sediments provides insights into the palaeogeography of the Eifel region during Tertiary times.

Figure 1 Geomorphological map of proglacial area of Yala (Dakpatsen) Glacier, Langtang Himal, Nepal (pdf 500 kB)

A series of minor moraine ridges are observed on the till surface in the proglacial area of Yala Glacier, Nepal Himalaya. The till surface, which is often fluted, consists ofsix different till sheets. It lies present glacial margin and the bulky terminal moraine ridges. These till sheets correspond to six re-advance stages during the general retreat which followed Little Ice Age ad- vance which formed the bulky terminal moraine ridges. Field observations and till fabric analysis suggest that the minor moraine ridges of Yala Glacier seem to be formed annually, by ice push. On the assumption that their annual character was maintained for a long time, and that the time span needed for each re-advance was proportional to the height of terminal moraine of each till sheet, the dating of Little fee Age moraines was attempted. The results indicate that Little Ice Age advances occurred in 1815 and in 1843, roughly simultanously with those in Europe.

National nitrogen budget for Denmark (excel-file 125 kB)

The data describe the flows of nitrogen between different pools and economic sectors within Denmark. The data are stored in an Excel spreadsheet that is divided into a number of worksheets. The National worksheet contains the national flows of nitrogen for the years 1990 to 2010 (note that for some flows, the data series is not complete for all years). These data underlie the national nitrogen flow figures in the main text of the paper. The remaining worksheets contain the data that underlie the figures presented in the detailed description of nitrogen flows between pools/sectors, that is in the Supplementary Material associated with the paper.