Climate warming and its impact on natural regional boundaries in China in the 1980s

The global climate warming accelerated in the 1980s has become a focus in the world. Based on the month by month and year by year temperature data from 160 representative stations throughout the country during 1951-1999, this paper analyses annual and four seasons' temperature variations of China since the 1980s. It was found out that the non-equalibrium response with relative great regional and seasonal differences is represented in the country's climate warming. In regional changes a trend of "warm in the north and cold in the south" occurs whereas in seasonal changes, the characters of "warm in winter and cool in summer" present. Significant verification of the temperature variations conducted in terms of mathematical statistics reveals that a confidence level of over 95% has been basically reached in areas north of the Yangtze River. Meanwhile, according to data of diurnal mean temperature steadily passing through accumulated temperature ≥10℃ from 335 stations since 1951 or since the founding of the stations in the early 1950s to 1999, comparative analysis of the data of the last 19 years with that of the first 30 years was conducted and the accumulated temperature ≥10℃ and the variation range of the persistent number of days ≥10℃ were obtained. It was concluded that a general northward shift of central subtropics, north subtropics, warm temperate zone, mesothermal zone and frigid temperate zone of eastern China was observed. The northward shift of north subtropics and warm temperate zone was obvious but changes of south subtropics and marginal tropics were insignificant. In western China, in addition to southwestern Yunnan, the Qinghai-Tibet Plateau and western Inner Mongolia where the temperature zones of each either shifted northward or trended to move upward, not much changes were found in other areas or they shifted southward slightly and declined.     

Damage and Changes in Mechanical Properties of a Gabbro Thermally Loaded up to 1,000°C

Thermal loading of rocks at high temperatures induces changes in their mechanical properties. In this study, a hard gabbro was tested in the laboratory. Specimens were slowly heated to a maximum temperature of 1,000°C. Subsequent to the thermal loading, specimens were subjected to uniaxial compression. A drastic decrease of both unconfined compressive strength and elastic moduli was observed. The thermal damage of the rock was also highlighted by measuring elastic wave velocities and by monitoring acoustic emissions during testing. The micromechanisms of rock degradation were investigated by analysis of thin sections after each stage of thermal loading. It was found that there is a critical temperature above which drastic changes in mechanical properties occur. Indeed, below a temperature of 600°C, microcracks start developing due to a difference in the thermal expansion coefficients of the crystals. At higher temperatures (above 600°C), oxidation of Fe²⁺ and Mg²⁺, as well as bursting of fluid inclusions, are the principal causes of damage. Such mechanical degradation may have dramatic consequences for many geoengineering structures.     

Urban stream temperature patterns: Spatial and temporal heterogeneity in the Philadelphia region,Pennsylvania, USA

Stream temperature is a critical water quality parameter that is not fully understood, particularly in urban areas. This study explores drivers contributing to stream temperature variability within an urban system, at 21 sites within the Philadelphia region, Pennsylvania, USA. A comprehensive set of temperature metrics were evaluated, including temperature sensitivity, daily maximum temperatures, time >20°C, and temperature surges during storms. Wastewater treatment plants (WWTPs) were the strongest driver of downstream temperature variability along 32 km in Wissahickon Creek. WWTP effluent temperature controlled local (1–3 km downstream) temperatures year-round, but the impacts varied seasonally: during winter, local warming of 2–7°C was consistently observed, while local cooling up to 1°C occurred during summer. Summer cooling and winter warming were detected up to 12 km downstream of a WWTP. Comparing effects from different WWTPs provided guidelines for mitigating their thermal impact; WWTPs that discharged into larger streams, had cooler effluent, or had lower discharge had less effect on stream temperatures. Comparing thermal regimes in four urban headwater streams, sites with more local riparian canopy had cooler maximum temperatures by up to 1.5°C, had lower temperature sensitivity, and spent less time at high temperatures, although mean temperatures were unaffected. Watershed-scale impervious area was associated with increased surge frequency and magnitude at headwater sites, but most storms did not result in a surge and most surges had a low magnitude. These results suggest that maintaining or restoring riparian canopy in urban settings will have a larger impact on stream temperatures than stormwater management that treats impervious area. Mitigation efforts may be most impactful at urban headwater sites, which are particularly vulnerable to stream temperature disruptions. It is vital that stream temperature impacts are considered when planning stormwater management or stream restoration projects, and the appropriate metrics need to be considered when assessing impacts.     

Disproportionation of Ni2SiO4 to stishovite plus bunsenite at high pressures and temperatures

Samples of Ni₂SiO₄ in both olivine and spinel phases have been compressed to pressures above 140 kbar in a diamond-anvil cell and heated to temperatures of 1400–1800°C using a continuous YAG laser. After quenching and releasing pressure, X-ray diffraction examination indicates that the samples disproportionate to a mixture of stishovite (SiO₂) and bunsenite (NiO) at pressures between 140 and 190 kbar. The exact disproportionation pressure is not certain due to transient increases in pressure during the local and rapid heating. However, thermodynamic calculations suggest that the transition pressure is about 192 ± 4 kbar at 1545°C and that the equation of the spinel-mixed oxides phase boundary isP(kbar) = 121 + (0.046 ± 0.020) T (°C).     

Effect of annealing temperature on the reactivity of Lunar fines toward adsorbed water

The ability of adsorbed water to react with feldspar-rich lunar soils, create fine pores, and expand the specific surface area is reduced about five-fold if the fines are heated at 700°C rather than 300°C. The loss of reactivity is attributed to the annealing of radiation damage tracks which reduces their etchability by water. Although the pore volume which can be induced decreases drastically, the distribution of pore sizes is not altered significantly. Most of the induced pores have a width of about 45Åwith a smaller population concentrated at about 120Å. For fines without water treatment, loss of specific surface area by sintering does not occur at temperatures below 700°C.     

Effects of a variety of impacts on seagrass restoration in Jamaica

For the first time seagrass rehabilitation was attempted in a tropical nation, Jamaica. Repairs to a variety of developmental impact types were attempted with test plots: dredge and fill, bauxite and oil spills, channelization, urban run-off, urban sewage, river bulkheading, jetty construction and artificial beach, industrial lagoons, saline lagoons, thermal effluents, and cement tailings. Three species were routinely planted (Thalassia testudinum, Halodule wrightii, Syringodium filiforme) plus Ruppia maritima in saline lagoons, each by two planting techniques. Types of damage which were successfully attempted to be restored for the first time were from heated wastes, bauxite spills, jettied river mouths, small scale oil spills, and diluted urban wastes. Types of pollution damage previously repaired in subtropics and temperate zones, which could be successfully repaired in the tropics also were dredge and fill and urban run-off. Erosion seagrass restoration repair was partially successful at some sites. Attempts to repair high salinity lagoons (up to 160‰) and cement tailings were unsuccessful. Functional species were found which could tolerate ongoing pollutant loads in some cases.     

Habitat restoration after pipeline construction in a tropical estuary: Seagrasses

In 1981 the Florida Keys Aquaduct Authority permitted the construction of a new water transmission pipeline through the Florida Keys, USA. The seagrasses Halodule wrightii and Thalassia testudinum in an estuary and wetland area north of Key Largo would be removed by a portion of the pipeline construction. Consequently, government construction permit conditions required restoration of these seagrasses.After construction, Halodule shoots were planted over the pipeline trench in an area 6.1 × 975 m on 0.9 m centres. Additional transplantation of Halodule and Thalassia was deemed necessary, especially in areas lateral to the pipeline trench, and was done later in 1981 by a second party. Results after ten months showed that $\text{31.1 ± 0.9\% (}\text{X}\text{±}\text{S.E.}$) of the area in the pipeline trench was covered by Halodule shoots. 1261 Thalassia seedlings were observed in the entire affected pipeline area. This is the first report of pipeline damage restored with seagrasses.     

Large-scale seagrass restoration in a damaged estuary

After several years of environmental planning, and the Port of Miami Expansion Program having been started, a large-scale seagrass restoration project, including a test plot programme, was initiated in a damaged estuary in south-eastern Florida, Biscayne Bay, in 1982. For the project 13 test plots throughout the area were selected, totalling 10.38 acres in area, which is the largest test plot programme implemented to date, with the exception of our ongoing test plot programme in Jamaica (16.9 acres). Three seagrasses, Thalassia testudinum, Halodule wrightii and Syringodium filiforme, were transplanted at each test plot by two methods: 9.4–18.6 months after transplantation, survival and growth of the plants were measured (survival measurements taken by Connell Associates, Inc., 1983). Thalassia sprigs ranked first in survival followed by Halodule sprigs.Test plots differed widely in the survival and growth of the three species. Nine of the 13 plots had one species/method successful enough for further planting. Mid-bay sites damaged by dredging had two species surviving 60% or more. High turbidity sites were the least successful. Only Thalassia sprigs were successful at high energy sites. Syringodium sprigs showed poor survival overall, and are not recommended for transplanting. Thalassia seedlings appeared adequate in low energy sites, but required heavier anchoring in medium energy sites. The major impacts to the test plots were dredging, filling and urban run-off. No industrial effluent sites were included.     

Variations of Strength,Resistivity and Thermal Parameters of Clay after High Temperature Treatment

This paper reports the variations of strength, resistivity and thermal parameters of clay after high-temperature heating. Experiments were carried out to test the physical properties of clay heated at temperatures ranging from room temperature to 800°C in a furnace. The experiment results show that below 400°C the uniaxial compressive strength and resistivity change very little. However, above 400°C, both increase rapidly. At a temperature under 400°C, the thermal conductivity and specific heat capacity decrease significantly. The thermogravimetric analysis (TG) and differential scanning calorimeter (DSC) test indicate that a series of changes occur in kaolinite at temperatures from 400 to 600°C, which is considered the primary cause of the variation of physical and mechanical properties of clay under high temperatures.     

Detection of thermal pollution from power plants on China’s eastern coast using remote sensing data

The acceleration of the industrialization process in China has increased the demand for electricity and triggered a power-plant building boom, especially along China’s eastern coast, where the economy gets off early and enjoys a fast development. The thermal plumes, residual chlorine, nuclides and other pollutions produced by the thermal and nuclear power plants have exerted an impact on the coastal eco-environment. To monitor the thermal pollution from the power plants at Yueqing Bay on the eastern coast, in this research, the distribution of sea surface temperature (SST) surrounding the power plants is obtained by using the SST retrieval methods developed for Landsat Enhanced Thematic Mapper Plus (ETM+), HJ-1B infrared sensor (IRS) and Terra moderate resolution imaging spectroradiometer (MODIS) data. The comparison of the SST retrieval results before and after the operation of power plants indicates that the total area of sea waters that is impacted by the thermal discharge from the two power plants at Yueqing Bay is approximately 17.95 km², with the highest SST rise of 4.5 °C appearing over the waters around the outlet of the Huaneng Yuhuan power plant on the eastern shore, whereas the highest SST rise around the Zheneng Yueqing power plant on the western shore reaches 3.8 °C. The intensity and scope of influence of the thermal discharge mainly depend on the installed capacity of power plants, coastal terrain, and tide. Although the area where the SST rise is more than 3 °C is not large, thermal discharge still has an impact on bay ecosystems due to the relatively closed nature of the bay environment. Due to the influence of rising water temperatures on the reproduction and individual evolution of fish, shrimp, crabs, shellfish and other aquatic creatures, in the long term, the thermal pollution from coastal power plants will affect the volume of natural fishery and biological resources throughout the waters. The quantitative retrieval results also suggest that relative to MODIS data, Landsat ETM+ and HJ-1B IRS data with a high spatial resolution are more applicable to the estimation of small-scale SST, and IRS data with a high temporal resolution are more helpful in the study of spatio-temporal variability of thermal plumes from coastal power plants.     

Longitudinal and temporal thermal patterns of the French Rh?ne River using Landsat ETM+ thermal infrared images

Understanding the thermal regime of rivers is a key issue for predicting ecosystem change in the context of global warming. However, water temperature is not only influenced by air temperature. To better highlight relative contribution of factors controlling water temperature, we used satellite thermal infrared (TIR) images from Landsat ETM+ to investigate longitudinal and temporal variations in thermal patterns of the French Rh?ne River. Because satellite TIR remote sensing is limited to large rivers, we used an automated water extraction technique to remove pixels contaminated by terrestrial surfaces. We calculated water surface temperatures of the 500?km long reach for 83 dates between 1999 and 2009. The average accuracy and uncertainty of our data, ±1.1 and ±0.4°C for reaches with more than 3?pixels across and ±1.4 and ±0.5°C for reaches with one to 3?pixels across, are comparable to other satellite TIR studies of rivers. Our results confirmed previous studies on the thermal impacts of tributaries and nuclear power plants on the Rh?ne, providing an understanding of their seasonal pattern and their longitudinal impact. We showed temperature differences of 0?C2°C within the largest hydroelectric bypass facilities between the bypass section and the canal, with Montélimar and Caderousse showing the most pronounced differences. Discussion points concern the potential impacts of tributaries and nuclear power plants on the spatio-temporal thermal patterns, as well as the factors responsible for thermal differences in the bypass facilities: length and minimum flow of the bypass section, and tributaries coming into this reach.     

Large-scale seagrass restoration in a damaged estuary

This investigation in Biscayne Bay, Florida, describes four large scale implementation attempts after an extensive test plot programme in which 13 locations throughout the impacted northern portion of the bay were examined, using three species and two restoration techniques per area. Season of planting for three species and three techniques were examined in 2.27 hectares and 9.09 hectares. A large floating scoop cut approximately 2 × 1 m sods from a seagrass bed scheduled to be buried by a beach fill project. These were subdivided, transported and planted in 73.3 areas (61 m × 61 m each). Over one million plants were planted in a total of 59.6 ha.Success in large scale implementation survival occurred in Phase III (9.09 ha) (Thalassia sprigs: 89% medium depth, 88% deep; Halodule sprigs: 35% shallow and 38% medium depth, 19% deep) all growing with appreciable lateral expansion and Phase IV (32.32 ha) with substantial plug survival (12 month quantitative survival 65–75%) of Thalassia and Syringodium.Animals ranging from commercial fisheries species (lobster, shrimps, crab, conch, fish) to food chain animals (echinoderm, manatee, hundreds of small invertebrates, egg cases, and larva) were seen to rapidly recolonize these areas. If the United Nations' value of more than $187,000 per hectare for seagrasses is assessed, a value of $9 million has been re-established by creating productive bay bottom in areas which have lain barren sand and silt for many decades. Less than a 10% of the value was spent in planting costs (including expensive test plot studies, which were part of federal government permit conditions).     

Testing the limitations of artificial protein degradation kinetics using known-age massive Porites coral skeletons

High-temperature isothermal heating of biominerals has commonly been used to artificially accelerate protein degradation in order to extrapolate kinetic parameters to the lower temperatures experienced in vivo and in the burial environment. It is not easy to test the accuracy of these simulations due to the difficulty of finding samples of known age held at a known temperature. We compare protein degradation in the intra-crystalline organic matrix of heated (80 °C, 110 °C, and 140 °C) massive Porites sp. coral to that directly measured in the skeleton of colonies growing at ∼26 °C and deposited over the last five centuries. This provides the opportunity to critically evaluate the underlying assumption that high-temperature experiments accurately mimic degradation processes and kinetics occurring in a ‘naturally aged’ biomineral. In all samples the intra-crystalline protein fraction was isolated and the L- and D- concentration of multiple amino acids measured using reverse-phase high-performance liquid chromatography (RP-HPLC). There was no evidence of a failure of the closed system in the high-temperature experiments (assessed by X-ray diffraction, thermogravimetric analyses and determination of leached amino acid concentration). We compared conventional methods for estimation of kinetic parameters with a new ‘model-free’ approach that makes no assumptions regarding the underlying kinetics of the system and uses numerical optimisation to estimate relative rate differences. The ‘model-free’ approach generally produced more reliable estimates of the observed rates of racemization in ‘naturally aged’ coral, although rates of hydrolysis (as estimated from the release of free amino acids) were usually over-estimated. In the amino acids for which we were able to examine both racemization and hydrolysis (aspartic acid/asparagine, glutamic acid/glutamine and alanine), it was clear that hydrolysis was less temperature sensitive than racemization, which may account for the differences in degradation patterns observed between the ‘naturally aged’ coral and high-temperature data. It is clearly important to estimate the individual temperature dependence of each of the parallel reactions.     

Synthesis of a perovskite-type polymorph of CaSiO3

Synthetic crystalline (wollastonite) and glass forms of CaSiO₃ have been compressed to loading pressures above 160 kbar and heated to about 1500° C by a laser in a diamond-anvil cell. After cooling, an X-ray diffraction study carried out whilst the sample was maintained at high pressure revealed that it had transformed to a cubic perovskite-type 3olymorph with a = 3.485 ± 0.008A?. After release of pressure, however, the sample showed a mixture of glass plus a few weak lines corresponding to ε-CaSiO₃ which is thus interpreted as a retrogressive transition product. The density of the perovskite polymorph of CaSiO₃ is about 9.2% greater than that of an isochemical mixture of CaO + SiO₂ (stishovite) at about 160 kbar.     

Melting relationships in CaO-CO2 and MgO-CO2 to 36 kilobars with comments on CO2 in the mantle

The melting curves of CaCO₃ and MgCO₃ have been extended to pressures of 36 kb by experiments in piston-cylinder apparatus. At 30 kb, the melting temperatures of calcite and magnesite are 1610°C and 1585°C, respectively. New data for the magnesite dissociation reaction permit the location of an invariant point for the assemblage magnesite + periclase + liquid + vapor near 26 kb-1550°C. New data are also presented for the calcite-aragonite transition at 800°C, 950°C and 1100°C. At pressures above 36–50 kb, calcite and magnesite melt at temperatures lower than the solidus of dry mantle peridotite. Natural and experimental evidence suggests that carbon dioxide in the Earth's mantle could be present in a variety of forms: (a) a free vapor phase, (b) vapor dissolved in silicate magma, (c) crystalline carbonate, (d) carbonatite liquid, (e) carbon-bearing silicate analogs, or (f) carbonato-silicates (such as scapolite, spurrite, tilleyite, and related compounds).     

Paleomagnetic evidence for low-temperature emplacement of the phreatomagmatic Peperino Albano ignimbrite (Colli Albani volcano, Central Italy)

The Peperino Albano (approximately 19–36 ka old) is a phreatomagmatic pyroclastic flow deposit, cropping out along the slopes of the associated Albano maar (Colli Albani volcano, Italy). The deposit exhibits lateral and vertical transitions from valley pond to veneer facies, as well as intracrater facies. We present the results of a paleomagnetic study of thermal remanent magnetization (TRM) of the lithic clasts of the Peperino Albano ignimbrite that provide quantitative estimates of the range of emplacement temperatures across the different facies of the ignimbrite. Emplacement temperatures estimated for the Peperino Albano ignimbrite range between 240° and 350°C, with the temperatures defined in the intracrater facies being generally lower than in the valley pond and veneer facies. This is possibly due to the large size of the sampled clasts in the intracrater facies which, when coupled with low temperature at the vent, were not completely heated throughout their volume during emplacement. The emplacement temperatures derived from the paleomagnetic results are in good agreement with the presence of un-burnt plants at the base of the ignimbrite, indicating that the temperature of the pyroclastic flow was lower than the temperature of ignition of wood. Paleomagnetic results from the Peperino Albano confirm the reliability of the paleomagnetic approach in defining the thermal history of pyroclastic flow deposits.     

40Ar/39Ar dating of the long range dikes,Newfoundland

Stepwise outgassing experiments were performed on eleven whole rock samples from a sequence of diabase dikes from the Great Northern Peninsula. Gas released at high temperatures (> ? 925–950°C) was consistently characterized by anomalously high apparent ages. These are attributed to the release of excess radiogenic argon, gas which probably resides in the mineral augite. At temperatures below ? 700°C, a wide range in apparent age was observed. On the other hand, the medium temperature region (? 700–950°C) is characterized by a relatively small range in apparent age. Data points corresponding to this region are rather well correlated in an isochron-type diagram; the slope of the best-fitting straight line corresponds to an aget = 605 ± 10m.y. We suggest that the outgassing of unaltered plagioclase is dominating the age spectra in this temperature interval. Consequently, we take 605 ± 10 m.y. as the time of emplacement of the Long Range dike swarm. This event may have marked the opening of a proto-Atlantic Ocean. The Acadian Orogeny (perhaps the ocean-closing event ? 380 m.y. ago) appears to be recorded in the low-medium temperature regions in the cases of two rather extensively altered samples.     

Measurement of the adiabats of quartz,forsterite, and magnesium oxide at high pressures and high temperatures and adiabatic gradient in the mantle

The geophysically-important adiabat (?T/?P)_s has been measured at pressures up to 50 kbar and temperatures up to 1000°C. A simple power law describes the relationship between (?T/?P)_s and the compression of the material. The power is independent of the material and of the temperature within the uncertainty. This consistency in the power allows the extrapolation of the adiabat to pressure and temperature conditions of the mantle of the earth. The adiabatic gradient is shown to be significantly smaller than the melting gradient.     

Nitrogen contents and isotopic ratios of clasts from the enstatite chondrite Abee

Nitrogen contents and isotopic ratios have been determined for three clasts from the enstatite chondrite Abee by stepwise heating. The clasts possess a wide range in nitrogen content, ranging from 254 to 850 ppm, whereas the nitrogen isotopic ratios are nearly identical atδ¹⁵N= ?29.2±0.6‰. A refractory inorganic nitrogen-bearing phase contains about 90% of the nitrogen which is released at temperatures of 1000°C and above. The stepwise heating experiments suggest the possible existence of two other distinct nitrogen components, released at low (770°C) and high (1500°C) temperatures.     

Effect of temperature on embryonic and larval development of bream (Abramis brama L.)

Influence of water temperature on embryonic and larval development of bream (Abramis brama L.) was stdied. Eggs of bream were incubated at eight constant water temperatures between 13.2 and 26.8°C. The temperature of 21.1°C gave highest hatching success, with no abnormalities in the eleutheroembryos and lowest mortality observed between eyed egg stage and the time of hatching. Developmental rate increased with increasing temperature. Duration of embryonic development (y; hours) decreased with increasing incubation temperature (x; °C) according to the formula: y=910.1−65.88 x+1.318 x². Larvae were reared at eight constant temperatures ranging from 13.5 to 34.0°C. The instantaneous growth rate in wet weight increased with increasing test temperature from 13.5 to 29.9°C, and then decreased at higher temperatures. Individual growth of fish and biomass production rate were highest at 27.9°C. This temperature is considered optimal when food availability and photoperiod are no limiting factors.