Evaluation of a low‐cost temperature measurement system for environmental applications

Thermochron iButtons incorporate the latest in digital technology, making them smaller, less expensive, durable and potentially more reliable than many other temperature logging devices. The objective of this study was to test the accuracy of an inexpensive air temperature measurement system, composed of a Thermochron iButton and radiation shield. Sixty‐one iButtons were subjected to a sequence of two water baths (0 °C and 24·9 °C) to assess the absolute accuracy of the sensors. Five solar radiation shields were tested in a greenhouse setting to evaluate the reduction in radiative heating. Significant differences (p < 0·05) were detected between instruments subsequent to both water‐bath treatment analyses. The accuracy of the sensors was well within the manufacturer's stated specification of ±1·0 °C with a collective temperature variance of ±0·21 °C. Temperature responses generated by the Thermochron iButtons in different radiation shields were consistent, but varied significantly (p < 0·05) from 28 to 44 °C based on diurnal temperature ranges. Results indicate that the Thermochron iButton is an accurate, inexpensive alternative to more expensive temperature data‐logging systems, and is well suited for obtaining quality spatially distributed data for hydrologic and water quality investigations. Copyright © 2005 John Wiley & Sons, Ltd.     

Synoptic climatology of nuisance flooding along the Atlantic and Gulf of Mexico coasts,USA

Natural Hazards - Nuisance flooding (NF; also known as high-tide, or “sunny day” flooding) is an increasingly prevalent phenomenon afflicting coastal developments worldwide. NF often...     

Analysis of loess landslide mechanism and numerical simulation stabilization on the Loess Plateau in Central China

Natural Hazards - Loess landslides have complicated deformation mechanisms. Accurately describing the internal failure deformation of loess landslides and establishing a theoretical method of...     

Integrating international linguistic minorities in emergency planning at institutions of higher education

Natural Hazards - Research concerning the behavior of international linguistic minorities at institutions of higher education during disasters is very limited. Many international groups suffer from...     

Experimental constraints on the mobility of Rhenium in silicate liquids

The volatization of Rhenium (Re) from melts of natural basalt, dacite and a synthetic composition in the CaO-MgO-Al₂O₃-SiO₂ system has been investigated at 0.1 MPa and 1250-1350 °C over a range of fO₂ conditions from log fO₂ = −10 to −0.68. Experiments were conducted using open top Pt crucibles doped with Re and Yb. Analysis of quenched glasses by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) normal to the melt/gas interface showed concentration profiles for Re, to which a semi-infinite one-dimensional diffusion model could be applied to extract diffusion coefficients (D). The results show Re diffusivity in basalt at 1300 °C in air is log D_Re = −7.2 ± 0.3 cm²/s and increases to log D_Re = −6.6 ± 0.3 cm²/s when trace amounts of Cl were added to the starting material. At fO₂ conditions below the nickel-nickel oxide (NNO) buffer Re diffusivity decreases to and to in dacitic melt. In the CMAS composition, . The diffusivity of Re is comparable to Ar and CO₂ in basalt at 500 MPa favoring its release as a volatile. Our results support the contention that subaerial degassing is the cause of lower Re concentrations in arc-type and ocean island basalts compared to mid-ocean ridge basalts.     

Estimating long-term soil respiration rates from carbon isotopes occluded in gibbsite

Carbon occluded in the soil gibbsite crystal structure at the Panola Mountain Research Watershed, Georgia, U.S. is presumed to be in isotopic equilibrium with the CO₂ respired from soil organics by microbes and plant roots. Fitting of the stable carbon isotopic data to a Fickian diffusion-based depth function results in an estimate of 47 gC m⁻² y⁻¹ for the long-term soil respiration rate. A numerical model that includes depth-dependent production and diffusion terms results in estimates of 28-12 gC m⁻² y⁻¹. These values range from 15 to 50 times less than the average of modern values for mixed deciduous forests in wet temperate climates. This disparity has several implications for our understanding of the geologic record of climate change, which include: (1) evidence for a cooler and seasonally drier climate during the mid-Holocene in the southeastern U.S., or (2) fluxes of carbon from the soil pool as recorded by soil mineral proxies (i.e., long-term soil respiration rates) under estimate atmosphere annual carbon flux measurements (i.e., short-term measures), and (3) the need to refine soil respiration models used to relate paleosol stable carbon isotopic measurements to paleo-atmospheric estimates.     

A multi-proxy lacustrine record of Holocene climate change on northeastern Baffin Island, Arctic Canada

Reconstructions of past environmental changes are critical for understanding the natural variability of Earth's climate system and for providing a context for present and future global change. Radiocarbon-dated lake sediments from Lake CF3, northeastern Baffin Island, Arctic Canada, are used to reconstruct past environmental conditions over the last 11,200 years. Numerous proxies, including chironomid-inferred July air temperatures, diatom-inferred lakewater pH, and sediment organic matter, reveal a pronounced Holocene thermal maximum as much as 5°C warmer than historic summer temperatures from 10,000 to 8500 cal yr B.P. Following rapid cooling 8500 cal yr B.P., Lake CF3 proxies indicate cooling through the late Holocene. At many sites in northeastern Canada, the Holocene thermal maximum occurred later than at Lake CF3; this late onset of Holocene warmth is generally attributed to the impacts of the decaying Laurentide Ice Sheet on early Holocene temperatures in northeastern Canada. However, the lacustrine proxies in Lake CF3 apparently responded to insolation-driven warmth, despite the proximity of Lake CF3 to the Laurentide Ice Sheet and its meltwater. The magnitude and timing of the Holocene thermal maximum at Lake CF3 indicate that temperatures and environmental conditions at this site are highly sensitive to changes in radiative forcing.     

A comparison of permafrost prediction models along a section of Trail Ridge Road, Rocky Mountain National Park, Colorado, USA

The distribution of mountain permafrost along Trail Ridge Road (TRR) in Rocky Mountain National Park, Colorado, was modeled using ‘frost numbers’ and a ‘temperature of permafrost model’ (TTOP) in order to assess the accuracy of prediction models. The TTOP model is based on regional observations of air temperature and heat transfer functions involving vegetation, soil, and snow; whereas the frost number model is based on site-specific ratios of ground temperature measurements of frozen and thawed degree-days. Thirty HOBO© temperature data loggers were installed near the surface as well as at depth (30 to 85 cm). From mid-July 2008 to 2010, the mean annual soil temperature (MAST) for all surface sites was − 1.5 °C. Frost numbers averaged 0.56; TTOP averaged − 1.8 °C. The MAST was colder on western-facing slopes at high elevations. Surface and deeper probes had similar MASTs; however, deeper probes had less daily and seasonal variation. Another model developed at the regional scale based on proxy indicators of permafrost (rock glaciers and land cover) classified 5.1 km² of permafrost within the study area, whereas co-kriging interpolations of frost numbers and TTOP data indicated 2.0 km² and 4.6 km² of permafrost, respectively. Only 0.8 km² were common among all three models. Three boreholes drilled within 2 m of TRR indicate that permafrost does not exist at these locations despite each borehole being classified as containing permafrost by at least one model. Addressing model uncertainty is important because nutrients stored within frozen or frost-affected soils can be released and impact alpine water bodies. The uncertainty also exposes two fundamental problems: empirical models designed for high latitudes are not necessarily applicable to mountain permafrost, and the presence of mountain permafrost in the alpine tundra of the Colorado Front Range has not been validated.     

The level and nature of sustainability for clusters of abandoned limestone quarries in the southern Palestinian West Bank

The question of how sustainable a mining site is at the end of its operational life has been somewhat unanswered. The fundamental problem has been how to evaluate the sustainability of a mining site once operations cease and is abandoned. Environmental Impact Assessment (EIA) is certainly a way to evaluate sustainability of such sites, but only through inference and subjective evaluation. This is because the topic of sustainability still hotly debated, and is predominantly focussed on an anthropocentric approach. Even with quantitative-based EIAs, the question is how to directly evaluate sustainability from the data available using a consistent quantitative approach rather than on a case-by-case basis or subjective evaluation.However, by using the ideas and concepts concerning the coupled relationship between the environment and humans prevalent in sustainability science, the question of what is and how to evaluate sustainability has become capable of being answered. Based on previous work of the author in the development and application of a mathematical model of sustainability, the paper applies the model to the results of a quantitative EIA evaluation for nine clusters of abandoned limestone quarries located in the southern Palestinian West Bank.The results indicate that seven of the nine clusters were deemed to be unsustainable, whilst the other two clusters were considered as sustainable at a very weak level only. The results are discussed within the broader context of the coupled environment-human system using one of the supporting frameworks for the development and application of the mathematical model of sustainability: Earth System Analysis. Within this context, the discussion indicates the fact that unmanaged impacts by humans has created the situation for unsustainability to occur. The paper therefore provides for the clearest indication yet of the nature of sustainability at the end of the mining operational life-cycle without an effective and proper management strategy or policies.     

Leaf wax δ2H and varve-thickness climate proxies from proglacial lake sediments, Baffin Island, Arctic Canada

We present a multiproxy paleoclimate record using leaf wax hydrogen isotopes (??²H_wax) and varve thickness from Arctic proglacial lake sediments. We also provide one of the first evaluations of the utility of ??²H_wax as a paleoclimate proxy in Arctic proglacial lakes. We compare varve thickness and ??²H_wax at sub-decadal resolution from 1948 to 2004 AD, and at sub-centennial resolution from 1450 to 2004 AD. Varve thickness and ??²H_wax both contain large interannual variability and are anti-correlated during the late twentieth century, suggesting that both proxies respond rapidly, but by different mechanisms, to catchment-scale forcings. At longer time scales, varve thickness exhibits a strong response to Little Ice Age cooling (1661?C1827 AD in this record) but does not show evidence for twentieth century warming recorded throughout the Arctic. ??²H_wax does record regional-scale temperature changes, with more ²H-depleted values during the Little Ice Age and an abrupt change to more ²H-enriched values in the twentieth century. This corresponds well with a recent Arctic-wide temperature reconstruction in which the seventeenth century is the coldest interval, and the twentieth century is the warmest interval. Our results suggest that ??²H_wax is a promising proxy that can be applied at high resolution in proglacial Arctic lakes.