Addressing the value of art in cartographic communication

Contemporary methods for depicting the earth and its cultural and natural attributes use graphic and non-graphic formats, maps and map-related artefacts, for visualizing geography and building virtual landscapes and environments. The discipline area of cartography, traditionally, has applied art (design), science and technology to map making to design and realise these products. Prior to the mid-1950s, cartographic artefacts were built under the theoretical and practical ‘umbrella’ of this partnership of art, science and technology. However, since then, the theory and methodology associated with visualizing geography has focused on Science and Technology, and away from Art. This ‘move’ away from art was accelerated by: (1) computing, computers and complete automated systems; and (2) the ‘quest’ to gain ‘scientific legitimacy’ by using scientific visualization as a lodestone for gauging the ‘quality’ of theories and applications.Science and Technology has been embraced by cartography as a means to ensure that what is presented is scientifically ‘correct’ — products are considered to ‘work’ if they are scientifically ‘elegant’, ‘technologically’ ‘buildable’ and ‘deliverable’ using contemporary communication systems. But, it is argued, science or technology, need not always take on primary roles, and there now is a need to address the role that design should take to facilitate the further development of contemporary cartography, especially in the areas where new media has been applied to facilitate the building of geographical visualization tools.This paper will address how, by incorporating art elements into the design criteria of geographical visualization artefacts, ‘different’ visualization tools might be provided using all three elements of cartography: art, science and technology.     

Mapping distortion of detectors in UVIT onboard AstroSat observatory

Ultraviolet Imaging Telescope (UVIT) is one of the payloads onboard AstroSat, India’s first multi-wavelength Astronomy mission. UVIT is primarily designed to make high resolution images in wide field, in three wavelength channels simultaneously: FUV (130–180 nm), NUV (200–300 nm) and VIS (320–550 nm). The intensified imagers used in UVIT suffer from distortions, and a correction is necessary for these to achieve good astrometry. In this article we describe the methodology and calculations used to estimate the distortions in ground calibrations.     

Journey‐to‐Work Patterns in the Age of Sprawl: Evidence from Two Midsize Southern Metropolitan Areas*

Among others, one commonly identified negative consequence of urban sprawl is an increase in the length of the journey to work. However, there has been more discussion of this than serious scrutiny, hence the relationship between urban sprawl and commuting patterns, especially at the intraurban level, remains unclear. Using the 2000 Census Transportation Planning Package (CTPP) data for two Southeastern metropolitan areas, this research investigates the extent to which workers living in sprawl areas commute farther to work than those living in higher density areas. The analysis of variance confirms that workers commuting from sprawl areas to urban areas experience a longer commute in terms of time as well as mileage, though this varies when workplace and home locations are taken into account. However, multivariate statistical results suggest that there are limits to the utility of sprawl as a predictor of travel behavior compared to workers' socioeconomic characteristics, as other factors appear to be equally or more important.     

Estimating groundwater storage changes in the Mississippi River basin (USA) using GRACE

Based on satellite observations of Earth’s time variable gravity field from the Gravity Recovery and Climate Experiment (GRACE), it is possible to derive variations in terrestrial water storage, which includes groundwater, soil moisture, and snow. Given auxiliary information on the latter two, one can estimate groundwater storage variations. GRACE may be the only hope for groundwater depletion assessments in data-poor regions of the world. In this study, soil moisture and snow were simulated by the Global Land Data Assimilation System (GLDAS) and used to isolate groundwater storage anomalies from GRACE water storage data for the Mississippi River basin and its four major sub-basins. Results were evaluated using water level records from 58 wells set in the unconfined aquifers of the basin. Uncertainty in the technique was also assessed. The GRACE-GLDAS estimates compared favorably with the well based time series for the Mississippi River basin and the two sub-basins that are larger than 900,000 km². The technique performed poorly for the two sub-basins that have areas of approximately 500,000 km². Continuing enhancement of the GRACE processing methods is likely to improve the skill of the technique in the future, while also increasing the temporal resolution.     

Millimetre-scale variation in metamorphic permeability of marbles during transient fluid flow: an example from the Reynolds Range, central Australia

Fluid inclusions from a biotite-garnet schist in the Southern Aravalli Mountain Belt (India) give information on both peak metamorphic conditions and post-peak metamorphic processes during uplift. A combination of careful petrography, microthermometry and Raman spectroscopy reveals the presence of at least five generations of enclosed fluids. Lower amphibolite-facies pressure-temperature conditions of the growth of garnet rims are reproduced by the highest fluid density of the relatively oldest inclusion type of CO₂ (±N₂)-rich compositions. A calculated fluid composition in the COH system, in equilibrium with the graphite buffer corresponds to a CO₂-rich fluid at metamorphic conditions. However, the results of these calculations are very sensitive to small fluctuations in oxygen fugacity and the accuracy of thermodynamic properties of mineral equilibria. Re-equilibration, conceived by specific size-density distribution and the absence of an aqueous phase in inclusions that contain nahcolite crystals, is monitored in these inclusions as post-peak metamorphic processes, like partial decrepitation and preferential leakage. The other fluid types represent heterogeneous fluid trapping of coexisting aqueous NaCl-bearing solutions with CO₂-CH₄-rich vapour bubbles in healed cracks, and probably the introduction of external fluids containing high salinity aqueous CaCl₂-rich solutions in nearly pure N₂ vapour bubbles, at lower P-T conditions. This study illustrates that fluid inclusions remain a valuable database of peak metamorphic conditions, moreover, alterations of the entrapped fluids and surrounding crystals are illustrative for specific exhumation evolutions. Received: 24 March 1999 / Accepted: 13 January 2000     

Controls on dissolved inorganic carbon and δC in cave waters from DeSoto Caverns: Implications for speleothem δC assessments

Unraveling the factors controlling the carbon chemistry and transport of carbon within extant karst systems has important implications concerning the assessment of time-series δ¹³C records of speleothems. Here we report the results of a 3-year study of total dissolved inorganic carbon [DIC] and δ¹³C_DIC from cave waters at DeSoto Caverns (Southeastern USA) that offer valuable insight on carbon transport and the accompanied isotope fractionations from end-member sources to speleothems.[DIC] and δ¹³C_DIC values of cave waters range from 0.2 to 6.0 mM and 2.7 to −12.9 (‰ VPDB), respectively. [DIC] and δ¹³C_DIC of “seasonal drips” show seasonal, albeit noisy, variability and are inversely related (δ¹³C_DIC = −2.49[DIC] + 0.64, r² = 0.84). A shallow pool fed by multiple drips shows a bimodal δ¹³C_DIC distribution with an isotopically heavier mode during winter (−4‰ to −5‰ VPDB) relative to summer months (−9‰ to −10‰ VPDB). A multi-year trend of decreasing water availability during the study period is not reflected in a response of cave water carbon chemistry suggesting that rainfall amount may not be a significant controlling factor of the carbon chemistry. Coupled cave air winter ventilation/summer stagnation and varying CO₂ fluxes through the soil horizon and epikarst exert the strongest influence on seasonal [DIC] and δ¹³C_DIC variability. Measured values of high [DIC] and low δ¹³C_DIC from cave waters collected during the summer/early fall closely approximate isotopic equilibrium conditions. Conversely, low [DIC] and high δ¹³C_DIC values during winter/early months indicate kinetically enhanced isotopic fractionations within the cave waters. The kinetically enhanced isotopic fractionation of partitioned between degassed CO₂ and precipitated CaCO₃(1000lnα_{[(CO2-HCO3)+(CaCO3(AR)-HCO3)]/2}) is greater by about a factor of two (−6.7 ± 0.3‰) relative to the same isotopic fractionation under equilibrium conditions (−3.1‰).On the basis of ¹⁴C mass balance and paired ¹⁴C-U/Th measurements we estimate that on average about ∼23% of C delivered annually by the drips to the aragonite stalagmites is derived from ¹⁴C-dead dolomite cap while the remainder of ∼77% is derived from ¹⁴C-live biomass. δ¹³C measurements of aragonite (n = 12) sampled from the tips of active speleothems during the summer months are consistent with theoretical aragonite δ¹³C values calculated using the shallow pool summer/early fall data thus confirming the δ¹³C seasonality in both drips and coeval aragonite. δ¹³C values of an active stalagmite section spanning the last 200 years show a normal distribution with a mean of −7.1 ± 1.2‰ (n = 81) and a mode of −7‰ to −8‰ that are statistically indistinguishable from the annual mean and mode of all dripwaters. Thus secular time-series δ¹³C records of stalagmites at DeSoto Caverns with resolving power >10⁻¹ year will likely carry the imprints of drip annual means that record climate-driven δ¹³C seasonal biases.     

Major-ion chemistry, ��13C and 87Sr/86Sr as indicators of hydrochemical evolution and sources of salinity in groundwater in the Yuncheng Basin, China

Processes controlling hydrogeochemistry in the Yuncheng Basin, China, were characterised using major-ion chemistry, ⁸⁷Sr/⁸⁶Sr ratios and ??¹³C values. Evapotranspiration during recharge increased solute concentrations by factors of ??5?C50 in deep palaeowaters, while higher degrees of evapotranspiration have occurred in shallow, modern groundwater. Aquifer sediments (loess) contain approximately 15 weight% calcite; trends in groundwater HCO₃ concentrations and ??¹³C values (ranging from ?16.4 to ?8.2??) indicate that carbonate weathering is a significant source of DIC. Groundwater ⁸⁷Sr/⁸⁶Sr ratios (0.7110?C0.7162, median of 0.7116) are similar to those in both loess carbonate (0.7109?C0.7116) and local rainfall (0.7112), and are significantly lower than Sr in aquifer silicates (0.7184?C0.7251). Despite evidence for substantial carbonate dissolution, groundwater is generally Ca-poor (<?10% of total cations) and Na-rich, due to cation exchange. Saturation with respect to carbonate minerals occurs during or soon after recharge (all calcite and dolomite saturation indices are positive). Subsequent carbonate dissolution in the deep aquifer must occur as a second-stage process, in response to Ca loss (by ion exchange) and/or via incongruent dissolution of dolomite and impure calcite. The latter is consistent with positive correlations between ??¹³C values and Mg/Ca and Sr/Ca ratios (r ²?=?0.32 and 0.34).     

Spectroscopic Observations of the 2011 Draconids Meteor Shower

Some past October Draconid shower meteoroids fell apart in a spray of fragments at the end of their trajectory before slowing down, from which it was concluded that these were among the most fragile meteoroids known. In those instances, the dust could not be reliably traced to a particular return of the parent comet 21P/Giaconini-Zinner. On October 8th, 2011, Earth was predicted to transverse the 1900 A.D. dust ejecta of the comet. In 1900, the comet’s perihelion distance first moved significantly inwards to the Sun and ejection conditions could have been unusual. An airborne observing campaign was organized, with several teams contributing imaging and spectrographic cameras to study the manner in which these meteoroids released the volatile element sodium during the ablation process in the Earth’s atmosphere. IMCCE, ESA, and the SETI Institute contributed spectrographic cameras based on low-light WATEC 902H2 Ultimate, low-light LCC1, and GenII XX1332 image intensified cameras. An outburst was observed, much as predicted. Despite a lack of bright meteors, a total of 15 Draconid spectra were recorded. All show evidence of an early release of sodium. The loss of sodium was observed to coincide with the formation of a distinct wake of fragments. The observations show that 21P/Giacobini-Zinner ejected fragile meteoroids during the return in 1900. Those grains may have lost some sodium even before impacting Earth.